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Engine Starts

Check if engine will start and idle for one minute. If engine starts and idles for one minute, go to next step. If engine does not start or starts but does not idle for one minute, go to step 130).

121) Verify Fuel Pump Is Off  Turn ignition on, and wait 5 seconds. Listen for motor noise from fuel pump. If fuel pump is off, go to step 126). If fuel pump is on, go to next step.

122) Check VCRM  Turn ignition off. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Turn ignition on. Listen for fuel pump noise. If fuel pump is off, turn ignition off. Replace VCRM. Reconnect all components. Repeat QUICK TEST. If fuel pump is on, turn ignition off and go to step 123).

123) Check HFP Relay & Circuits  Turn ignition off. Ensure VCRM is disconnected. Disconnect HFP relay. Relay is located in engine compartment fuse block. Turn ignition on. Listen to fuel pump. If fuel pump is off, go to next step. If fuel pump is on, turn ignition off. Repair short to power in power-to-fuel pump/FPM circuit. Reconnect all components. Repeat QUICK TEST.

124) Check For Short To Ground In HFP Circuit  Turn ignition off. Ensure VCRM and HFP relay are disconnected. Measure resistance between negative battery terminal and terminal No. 10 (Brown/White wire) at VCRM connector. If resistance is more than 10,000 ohms, replace HFP relay. Reconnect all components. Repeat QUICK TEST. If resistance is 10,000 ohms or less, repair short to ground in HFP circuit. Reconnect all components. Repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 124) to step 126). No test procedures have been omitted.

126) Check FPM Circuit Continuity  Turn ignition off. Disconnect and inspect PCM connector. Clean or repair connector as necessary. Install breakout box. Leave PCM disconnected. Disconnect HFP relay. Measure resistance between test pin No. 8 at breakout box and power-to-fuel pump terminal (Pink/Black wire) at HFP relay connector. See Fig 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in FPM circuit between PCM and splice to power-to-fuel pump circuit. Remove breakout box, and reconnect all components. Repeat QUICK TEST.

Fig 1: High Speed Fuel Pump (HFP) Relay Conn. Terminal ID (XB4)
G93F40688

127) Check For Short To Power In Left HO2S  Turn ignition off. Disconnect left HO2S. Measure resistance between HO2S SIGNAL terminal and KEY POWER terminal at HO2S connector. See Fig 2. If resistance is more than 10,000 ohms, to next step. If resistance is 10,000 ohms or less, replace HO2S. Reconnect all components. Repeat QUICK TEST.

Fig 2: Heater Oxygen Sensor (HO2S) Terminal ID (XB5)
G93J40690

128) Check For Short To Power In Left HO2S Circuit  Turn ignition off. Ensure left HO2S is disconnected. Disconnect and inspect PCM connector. Clean or repair connector as necessary. Turn ignition on. Measure voltage between negative battery post and HO2S SIGNAL terminal (Red/Black wire) at harness side of HO2S connector. See Fig 2. If voltage is less than 2 volts, replace PCM. Reconnect all components. Repeat QUICK TEST. If voltage is 2 volts or more, repair short to power in left HO2S circuit.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 128) to step 130). No test procedures have been omitted.

130) Check Inertia Fuel Shutoff (IFS) Switch  Turn ignition off. Disconnect IFS switch. IFS switch is located in left front of trunk. Ensure IFS switch button is in the down (set) position. Measure resistance between IFS switch terminals. If resistance is less than 5 ohms, reconnect IFS switch. Check for open in power-to-fuel pump circuit, open in fuel pump or poor fuel pump ground. Repair wiring as necessary. Repeat QUICK TEST. If resistance is 5 ohms or more, attempt to reset IFS switch or replace IFS switch. Reconnect all components. Repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 130) to step 135). No test procedures have been omitted.

135) Code 524, 543 & Continuous Memory Code 583  KOEO Code 524 or 543 indicates that when PCM commanded fuel pump on, voltage was not detected on Fuel Pump Monitor (FPM) circuit (PCM terminal No. 8). Code 524 refers to low speed output (VCRM terminal No. 24; Pink/Black wire). Code 543 refers to high speed output. It is not possible to distinguish between circuits due to vehicle wiring and fuel pump operating strategy. Continuous Memory Code 583 indicates that when fuel pump was activated, power-to-fuel pump exceeded normal current draw. This could be due to a hard fault or an intermittent condition. Following are possible causes for these faults. Without Continuous Memory Code 583

With Continuous Memory Code 583

If Continuous Memory Code 583 is present, go to next step. If Continuous Memory Code 583 is not present, go to step 144).

136) Attempt To Re-Generate Continuous Memory Code 583  Turn ignition off. Clear continuous memory. See CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Start engine. If engine will not start, crank engine for 5 seconds. Repeat KOEO SELF-TEST. If Continuous Memory Code 583 is present, code is a hard fault. Go to step 139). If Continuous Memory Code 583 is not present, code is intermittent. Go to next step.

137) Was KOEO Code 524 Or 543 Present In Step 136)  If KOEO Code 524 and/or 543 was present in step 136), an over-current condition (short to ground) was present sometime during last 80 warm-up cycles. Go to step 144). If KOEO Code 524 and/or 543 was not present in step 136), go to step 147).

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 137) to step 139). No test procedures have been omitted.

139) Attempt To Isolate Short To Ground  Turn ignition off. Clear continuous memory. Disconnect Inertia Fuel Shutoff (IFS) switch. IFS switch is located in left front of trunk. Crank engine for 5 seconds. Repeat KOEO SELF-TEST. If Continuous Memory Code 583 is present (disregard other codes), go to step 140). If Continuous Memory Code 583 is not present, check for short to ground in power-to-fuel pump circuit or fuel pump. Repair wiring or replace fuel pump as necessary. After repair is complete, repeat QUICK TEST.

140) Check For Short To Ground In Power-To-Fuel Pump/FPM Circuit  Turn ignition off. Ensure IFS switch is disconnected. Disconnect and inspect PCM and VCRM connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM and VCRM disconnected. Measure resistance between test pins No. 8 and 40 at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short to ground in power-to-fuel pump/FPM circuit. Remove breakout box, and reconnect all components. Clear continuous memory. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST.

141) Check VCRM  Turn ignition off. Ensure IFS switch is disconnected. Install breakout box. Leave PCM disconnected. Reconnect VCRM connector. Connect a jumper wire between test pins No. 22 and 40 at breakout box. Turn ignition on. Measure voltage between test pins No. 8 and 60 at breakout box. If voltage is more than 8.5 volts, replace PCM. Remove breakout box, and reconnect all components. Clear continuous memory. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST. If voltage is 8.5 volts or less, replace VCRM. Remove breakout box, and reconnect all components. Clear continuous memory. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 141) to step 144). No test procedures have been omitted.

144) Check If Engine Starts With High Speed Fuel Pump (HFP) Relay Disconnected  Turn ignition off. Disconnect HFP relay. Relay is located in engine compartment fuse block. Attempt to start engine. If engine does not start or starts but runs for less than one minute, go to next step. If engine starts and runs for one minute, reconnect HFP relay. Go to step 127).

145) Check for B (+) To VCRM  Turn ignition off. Ensure HFP relay is disconnected. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Connect negative lead of DVOM to negative battery post. Using positive lead of DVOM, measure voltage at terminals No. 4 (Yellow wire) and No. 5 (Yellow wire) at VCRM connector. If both voltage readings are more than 10.5 volts, go to next step. If any reading is 10.5 volts or less, repair open in B (+) supply to VCRM. Ensure all related fuses are okay. Reconnect all components. Repeat QUICK TEST.

146) Check Power-To-Fuel Pump Circuit Continuity  Turn ignition off. Disconnect HFP relay and VCRM. Measure resistance between terminal No. 24 (Pink/Black wire) and power-to-fuel pump terminal at HFP relay. See Fig 1. If resistance is less than 10 ohms, replace VCRM. Reconnect all components. Repeat QUICK TEST. If resistance is 10 ohms or more, repair open in power-to-fuel pump circuit between VCRM and Fuel Pump Monitor (FPM) splice. Reconnect all components. Repeat QUICK TEST.

147) Check For Intermittent Short To Ground In Power-To-Fuel Pump Circuit  Turn ignition off. Visually inspect power-to-fuel pump circuit between VCRM and fuel pump. Also, inspect Fuel Pump Monitor (FPM) circuit to PCM and power-to-fuel pump circuit at High Speed Fuel Pump (HFP) relay. Repair wiring as necessary. Install a fuel gauge or listen to fuel pump to check if fuel pump quits while performing wiggle test.

Start engine. Shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between VCRM, fuel pump, PCM and HFP relay. To simulate road shock, lightly tap on Inertia Fuel Shutoff (IFS) switch, fuel pump, HFP relay, VCRM and fuel pump. If fuel pump stops, fuel pressure drops or engine stalls or stumbles, a short to ground in power-to-fuel pump circuit has been detected. Isolate fault and repair as necessary. Clear continuous memory (Code 583 should have been set). Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST. If no fault is detected, go to next step.

148) Check For Intermittent Short To Ground In Power-To-Fuel Pump  Turn ignition off. Disconnect PCM, VCRM and fuel pump. Inspect connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM, VCRM and fuel pump disconnected. Connect a test light between test pins No. 1 (KAPWR) and No. 8 (FPM) at breakout box. Observe test light, and shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between VCRM, fuel pump, PCM and HFP relay. To simulate road shock, lightly tap on Inertia Fuel Shutoff (IFS) switch, fuel pump, HFP relay and VCRM. If a fault is detected, test light will turn on, indicating a short to ground. If a short to ground is detected, isolate fault and repair wiring as necessary. Start engine and wait 5 seconds. Turn ignition off. Repeat QUICK TEST. If a short to ground is not detected, fault is intermittent and cannot be duplicated at this time. Testing is complete. Reconnect all components. For further diagnosis, see the appropriate TESTS W/O CODES - EEC-IV (2.0L) article in the ENGINE PERFORMANCE section.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 148) to step 150). No test procedures have been omitted.

150) Continuous Memory Code 524, 543 Or 556  Continuous Memory Code 524 or 543 indicates that when PCM commanded fuel pump on, voltage was not detected at the power-to-fuel pump circuit. Code 524 refers to low speed output (VCRM terminal No. 24; Pink/Black wire). Code 543 refers to high speed output. It is not possible to distinguish between circuits due to vehicle wiring and fuel pump operating strategy. Following are possible causes for these faults.

Continuous Memory Code 556 indicates that sometime during vehicle operation, fuel pump primary circuit failure occurred. Possible cause for this fault is an open or short in fuel pump circuit (PCM terminal No. 22). If Continuous Memory Code 583 is also present, go to step 136). If Continuous Memory Code 583 is not present, go to next step.

151) Check Power-To-Fuel Pump & Fuel Pump Circuits  Start engine. Disconnect High Speed Fuel Pump (HFP) relay. Relay is located in engine compartment fuse block. Connect a test light between ground and power-to-fuel pump terminal at HFP relay connector. If a fault is detected, test light will go out, indicating a open FP circuit. Also, listen for engine stall/stumble or fuel pump turning off. Observe test light and perform the following:

If a short to ground is detected, isolate fault and repair wiring as necessary. Clear continuous memory. Repeat QUICK TEST. If Code 556 is present and a short to ground is not detected, go to next step. If Code 556 is not present and a short to ground is not detected, go to step 158).

152) Check For Intermittent Short To Ground In Fuel Pump Ckt.  Turn ignition off. Disconnect and inspect PCM and VCRM connectors. Clean or repair connectors as necessary. Connect ohmmeter between terminals No. 18 (Light Blue/Orange wire) and No. 1 (Black wire) at VCRM connector. Observe ohmmeter, and shake, wiggle and bend Light Blue/Orange wire (fuel pump circuit) between VCRM and PCM connectors. Also check fuel pump circuit to Data Link Connector (DLC). If a fault is detected, ohmmeter will show continuity, indicating a short to ground. If continuity exists, isolate fault and repair wiring as necessary. Clear continuous memory. Repeat QUICK TEST. If no continuity exists, fault is intermittent and cannot be duplicated at this time. Testing is complete. Reconnect all components. For further diagnosis, see TESTS W/O CODES - EEC-IV (2.0L) article in the ENGINE PERFORMANCE section.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 152) to step 155). No test procedures have been omitted.

155) Continuous Memory Code 542  Continuous Memory Code 542 indicates that one of the following conditions has occurred.

Start engine. Check for engine stall/stumble while performing the following (if possible, listen for fuel pump turning off). Shake, wiggle and bend Pink/Black wire (power-to-fuel pump circuit) between fuel pump and FPM splice. To simulate road shock, lightly tap on fuel pump, Inertia Fuel Shutoff (IFS) switch and VCRM. If engine stalls or stumbles, isolate fault and repair wiring as necessary. Clear continuous memory. Repeat QUICK TEST. If engine does not stall or stumble, go to next step.

156) Check For Intermittent Open Or Short In FPM, Power-To-Fuel Pump & Fuel Pump Ground Circuits  Turn ignition off. Disconnect and inspect PCM connector. Clean or repair connector as necessary. Install breakout box. Leave PCM disconnected. Connect a test light between test pins No. 8 and 37 at breakout box. Turn ignition on, engine off. Observe test light, and shake, wiggle and bend the following circuits.

To simulate road shock, lightly tap on Inertia Fuel Shutoff (IFS) switch, VCRM and HFP relay. If a fault is detected, test light will turn off indicating an open circuit. Test light will also turn off and fuel pump will run, if a short to power or HFP circuit short to ground is detected. If a fault is detected, isolate fault and repair wiring as necessary. Remove breakout box. Reconnect all components. Repeat QUICK TEST. If a fault is not detected, go to step 158).

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 156) to step 158). No test procedures have been omitted.
NOTE: Due to internal circuitry of PCM, an intermittent short to power in left HO2S signal may produce a Continuous Memory Code 524, 542 or 543.

158) Check For Short To Power In Left HO2S  Turn ignition off. Install breakout box. Leave PCM disconnected. Connect test light between test pins No. 43 and 40 at breakout box. Turn ignition on. Observe test light and shake, wiggle and bend Red/Black wire between left HO2S and PCM connector. To simulate road shock, lightly tap on left HO2S. If a fault is detected, test light will turn on bright, indicating a short to power. If a short to power is detected, isolate fault and repair wiring as necessary. Remove breakout box. Reconnect all components. Repeat QUICK TEST. If a short to power is not detected, fault is intermittent and cannot be duplicated at this time. Testing is complete. Reconnect all components. For further diagnosis, proceed to the appropriate TESTS W/O CODES - EEC-IV (2.0L) article in the ENGINE PERFORMANCE section.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 158) to step 160). No test procedures have been omitted.

160) Lack Of Power/Hard Start; Check HFP Relay Operation  Turn ignition off. Disconnect HFP relay. Relay is located in engine compartment fuse block. Measure voltage between negative battery post and B(+) terminal at HFP relay connector. See Fig 1. Turn ignition on. Measure voltage between IGN START/RUN terminal at HFP relay connector and negative battery post. If both voltage readings are more than 10.5 volts, go to next step. If any reading is 10.5 volts or less, repair open in B(+) or IGN START/RUN circuit. Also, ensure all related fuses are good. After repair is completed, reconnect all components. Recheck system operation.

161) Check Power-To-Fuel Pump Circuit Continuity  Turn ignition off. Disconnect HFP relay connector. Measure resistance between negative battery post and POWER-TO-FUEL PUMP terminal at HFP relay connector. See Fig 1. If resistance is less than 10 ohms, go to next step. If resistance is 10 ohms or more, repair open in power-to-fuel pump circuit between HFP relay and splice to main power-to-fuel pump circuit. After repair is completed, reconnect all components. Recheck system operation.

162) Check VCRM & HFP Circuit Operation  Turn ignition off. Reconnect HFP relay. Start engine. Run engine until normal operating temperature is reached. Turn ignition off. Disconnect HFP relay. Connect DVOM between terminals B(+) and HFP at HFP relay connector. See Fig 1. Ensure all accessories are off. Observe DVOM and start engine. Within 10 seconds of start, record voltage reading. Observe DVOM and allow engine to idle for 2 minutes. If voltage reading decreases 0.4 volt or more within 2 minutes of running engine, VCRM and HFP circuits are okay. Turn ignition off. Check HFP relay. Go to next step. If voltage reading does not decrease a minimum of 0.4 volt within 2 minutes of running engine, turn ignition off. Go to step 165).

163) Check HFP Relay  Turn ignition off. Disconnect HFP relay. Connect a jumper wire between positive battery post and IGN START/RUN terminal at HFP relay. See Fig 3. Connect one end of another jumper wire to HFP terminal at HFP relay. Listen to HFP relay and touch remaining end of jumper wire to negative battery post. If relay clicks, relay is working properly. Remove jumper wires and reconnect HFP relay. If relay does not click, replace relay. Reconnect all components. Recheck system operation.

Fig 3: High Speed Fuel Pump (HFP) Relay Terminal ID (XB6)
G93C40693
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 163) to step 165). No test procedures have been omitted.

165) Check HFP Circuit Continuity  Turn ignition off. Disconnect HFP relay. Disconnect and inspect VCRM connector. Clean or repair connector as necessary. Measure resistance between terminal No. 10 (Brown/White wire) at VCRM connector and HFP terminal at HFP relay connector. See Fig 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in HFP circuit (Brown/White wire). Reconnect all components. Recheck system operation.

166) Check For Short To Power In HFP Circuit  Turn ignition off. Ensure VCRM and HFP relay are disconnected. Turn ignition on. Measure voltage between negative battery post and HFP terminal at HFP relay connector. See Fig 1. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to power in HFP circuit. Reconnect all components. Recheck system operation.

167) Check For Short To Ground In HFP Circuit  Turn ignition off. Ensure VCRM and HFP relay are disconnected. Measure resistance between negative battery post and HFP terminal at HFP relay connector. See Fig 1. If resistance is more than 10,000 ohms, replace VCRM. Reconnect all components. Recheck system operation. If resistance is 10,000 ohms or less, repair short to ground in HFP circuit. Reconnect all components. Recheck system operation.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 167) to step 170). No test procedures have been omitted.

170) KOEO & Continuous Memory Code 587: Check Wiring Harness  Code 587 indicates a Data Link Connector (DLC) failure between PCM and VCRM. DLC includes data (+) and data (-) circuits. Following are possible causes for this fault.

Check wiring harness containing data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between VCRM and PCM connectors for proper installation, location (not close to high voltage wires) and for aftermarket modifications. Relocate or repair wiring as necessary. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If KOEO Code 587 is present and wiring is okay, go to next step. If Continuous Memory Code 587 is present and wiring is okay, go to step 180).

171) Check Data (+) & Data (-) Circuit Short To Power  Turn ignition off. Disconnect any test equipment connected to Data Link Connector (DLC). Leave equipment disconnected throughout procedure unless otherwise instructed. Disconnect and inspect VCRM and PCM connectors. Clean or repair connectors as necessary. Install breakout box. Turn ignition on. Leave PCM disconnected. Measure voltage between test pin No. 18 and 40 at breakout box. Also, measure voltage between test pin No. 19 and 40 at breakout box. If both voltage readings are less than 1.0 volt, go to next step. If any reading is 1.0 volt or more, repair short to power in Tan/Orange and/or Pink/Light Blue wire. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

172) Check For Short In Data (+) & Data (-) Circuits  Turn ignition off. Install breakout box. Disconnect PCM and VCRM. Measure resistance between test pins No. 18 and 40, and pins No. 19 and 40 at breakout box. Measure resistance between test pins No. 18 and 19. If all readings are greater than 10,000 ohms, go to next step. If any reading is less than 10,000 ohms, repair short circuit in data (+) (Tan/Orange wire) and/or data (-) (Pink/Light Blue wire) circuits. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

173) Check Data (+) & Data (-) Circuit Continuity  Turn ignition off. Disconnect and inspect VCRM and PCM connectors. Clean or repair connectors as necessary. Install breakout box. Turn ignition on. Leave PCM disconnected. Measure resistance between test pin No. 18 at breakout box and terminal No. 21 (Tan/Orange wire) at VCRM harness connector. Also, measure resistance between test pin No. 19 at breakout box and terminal No. 23 (Pink/Light Blue wire) at VCRM harness connector. If both resistance readings are less than 5.0 ohms, go to next step. If any reading is 5.0 ohms or more, repair open in Tan/Orange and/or Pink/Light Blue wire. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

174) Check Data Communication Link (DCL) In VCRM  Turn ignition off. Ensure all test equipment is disconnected from DLC. Ensure breakout box is installed and PCM is disconnected. Reconnect VCRM connector. Turn ignition on. Measure voltage between test pins No. 18 (data (+) circuit) and No. 19 (data (-) circuit) at breakout box. If voltage is between 3.5-5.3 volts, go to next step. If voltage is not between 3.5-5.3 volts, turn ignition off. Replace VCRM. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

175) Check Data (-) Circuit In VCRM  Turn ignition off. Ensure all test equipment is disconnected from Data Link Connector (DLC), breakout box is installed and PCM is disconnected. With VCRM connected, measure resistance between test pins No. 19 (data (-) circuit) and No. 40 (GND) at breakout box. If resistance is 1500-2500 ohms, go to next step. If resistance is not 1500-2500 ohms, turn ignition off. Replace VCRM. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off.

176) Verify That PCM Can Communicate On DCL  The purpose of this test is to verify that PCM can communicate on DCL. A scan tool is required for this test step. Follow manufacturer's instructions to hook up equipment. Turn ignition off. Remove breakout box. Reconnect PCM. Connect scan tool to DLC. Start engine. While in DCL display, view RPM Parameter Identification (PID). Monitor RPM, and change engine speed. If RPM PID is displayed and changes with engine speed, go to next step. If RPM PID is not displayed or is displayed but does not change with engine speed, go to step 179).

177) Verify DCL In VCRM  Turn ignition off. Ensure PCM and VCRM are connected. Turn A/C off. Enter Output State Diagnostic Test Mode (OS DTM). See OUTPUT STATE CHECK procedure under ADDITIONAL SYSTEM FUNCTIONS. Turn outputs off. Depress and hold throttle near Wide Open Throttle (WOT) until Malfunction Indicator Light (MIL) flashes once (about 10 seconds). Release throttle. Cooling fan should turn on. Depress throttle to turn cooling fan off. If cooling fan turns on and off as requested, exit OS DTM. Go to next step.

NOTE: Cooling fan can only be cycled once during OS DTM. To retest, exit and re-enter OS DTM.

If cooling fan does not turn on and off as requested, ensure OS DTM is operating properly. MIL should flash when throttle is depressed and released. If MIL does not flash, check throttle linkage and DLC connections. If OS DTM is operating properly, replace VCRM. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

178) Check DCL In VCRM  Turn ignition off. Ensure PCM and VCRM are connected. Disconnect cooling fan. Ensure A/C and defroster are off. Perform KOEO SELF-TEST. If KOEO Code 582 is present, reconnect cooling fan. No problem is indicated at this time. Data (+) and data (-) circuits test okay and DLC is operational in PCM. Reconnect all components. If KOEO Code 582 is not present, allow time for engine to cool down to verify that cooling fan does to come on. After engine is cooled, start engine and wait 10 seconds. Turn ignition off. Repeat KOEO SELF-TEST. If KOEO Code 582 is still not present, replace VCRM. Reconnect cooling fan. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST.

179) Check Data (+) & Data (-) Circuit Continuity To DCL  Turn ignition off. Install breakout box. Leave PCM disconnected. Disconnect scan tool from DLC. Measure resistance between test pin No. 18 at breakout box and data (+) terminal (Tan/Orange wire) at DLC. See Fig 4. Also measure resistance between pin No. 19 at breakout box and data (-) terminal (Pink/Light Blue wire) at DLC. If both readings are less than 5 ohms, replace PCM. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If any reading is 5 ohms or more, repair open circuit as necessary. After repair is complete, return to step 176).

Fig 4: Data Link Connector (DLC) Terminal ID (XB7)
G93H40433

180) Check For Intermittent In Data (+) & Data (-) Circuits.  Perform test while cooling fan is off. Start engine. Ensure A/C is off. Shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors. To simulate road shock, lightly tap on VCRM. VCRM will turn fan on if DLC fault is detected. If cooling fan turns on, for other than normal operation, isolate fault and repair wiring as necessary. Clear continuous memory. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If cooling fan does not turn on, go to next step.

181) Check For Intermittent Short In Data (+) & Data (-) Circuits  Turn ignition off. Disconnect test equipment from Data Link Connector (DLC). Disconnect and inspect PCM and VCRM connectors. Clean or repair connectors as necessary. Install breakout box. Leave PCM and VCRM disconnected. Connect a jumper wire between data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits at DLC. See Fig 4. Connect test light between test pins No. 19 and 37 at breakout box. Observe test light, and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors.

If a fault is detected, test light will turn on, indicating a short to ground. Disconnect jumper wire. Reconnect test light between test pins No. 19 and 40 at breakout box. Observe test light, and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors. If a fault is detected, test light will turn on, indicating a short to power. If a short is detected, isolate fault and repair wiring as necessary. Remove breakout box, and reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If a short is not detected, go to next step.

182) Check For Intermittent Open In Data (+) & Data (-) Circuits  Turn ignition off. Ensure breakout box is installed and PCM and VCRM are disconnected. Connect a jumper wire between terminals No. 21 (Tan/Orange wire) and No. 23 (Pink/Light Blue wire) at VCRM connector. Ensure jumper wire does not contact other terminals at VCRM connector. Using an ohmmeter, measure resistance between test pins No. 18 and 19 at breakout box. Observe ohmmeter, and shake, wiggle and bend data (+) (Tan/Orange wire) and data (-) (Pink/Light Blue wire) circuits between PCM and VCRM connectors.

If reading increases to more than 5 ohms at any time, isolate and repair open circuit and repair wiring as necessary. Remove jumper wire and breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C and ignition off. Repeat QUICK TEST. If reading stays at 5 ohms or less, fault is intermittent and cannot be duplicated at this time. Testing is complete. Remove jumper wire and breakout box. Reconnect all components.

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