Diagnostic Aids

Perform this test when directed by QUICK TEST. This CIRCUIT TEST is intended to diagnose:

Injector Driver Module (IDM).
Wiring harness circuit (EF).
Powertrain Control Module (PCM).

Fig 1: Identifying Injector Driver Module Feedback Circuit

1) DTC P1668

This DTC indicates a PCM/IDM communication error. Possible causes for this fault are:
- Faulty Injector Driver Module (IDM).
- Open or grounded circuit.
- Faulty Powertrain Control Module (PCM).
Perform KOEO ON-DEMAND SELF-TEST again. If DTC P1668 is not present, go to next step. If only DTC P1668 is present, go to step 3). If DTCs P1663, P1667 and P1668 are present, go to step 8). If DTC P1668 is present with DTC P1298 or P1667, go to CIRCUIT TEST V . If DTCs P1668 and P1663 are present, go to CIRCUIT TEST T . If DTCs P1668 and P1662 are present, go to CIRCUIT TEST W .

2) Check EF Circuit

Start engine and allow it to idle. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. Perform KOEO ON-DEMAND SELF-TEST . If DTC P1668 is present, locate and repair intermittent in wiring harness. Clear DTCs and repeat QUICK TEST . If DTC P1668 is not present, no problem is indicated at this time.

3) Check Circuit No. 818

Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Measure resistance between terminal No. 4 (Gray/White wire) at IDM connector and test pin No. 48 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/White wire. Clear DTCs and repeat QUICK TEST .

4) Check For Short To Ground

Turn ignition off. Measure resistance between test pin No. 48 and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are more than 10,000 ohms, go to next step. If any reading is 10,000 ohms or less, locate and repair short to ground in Gray/White wire. Clear DTCs and repeat QUICK TEST .

5) Check For Short To Power

Reconnect PCM to breakout box. Measure resistance between test pin No. 48 and test pins No. 55, 71 and 91 at breakout box. If any reading is 10,000 ohms or less, locate and repair short to power in Gray/White wire. Clear DTCs and repeat QUICK TEST . If all readings are more than 10,000 ohms, go to next step.

6) Check SIG RTN Circuit

Measure resistance of Gray/Red wire between test pin No. 91 at breakout box and terminal No. 2 at IDM connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Gray/Red wire. Clear DTCs and repeat QUICK TEST .

7) Check IDM Power

Disconnect IDM 40-pin connector. IDM is located in left side of engine compartment. Turn ignition on. Measure voltage between ground and terminal No. 14 (Dark Green/Light Green wire) at IDM wiring harness connector. If battery voltage is present, go to next step. If battery voltage is not present, go to CIRCUIT TEST W .

8) Check IDM Ground

Turn ignition off. Measure resistance between ground and terminal No. 26 (Black/White wire) at IDM connector. If resistance is less than 5 ohms, replace IDM. Clear DTCs and repeat QUICK TEST . If resistance is 5 ohms or more, locate and repair open circuit in Black/White wire. Clear DTCs and repeat QUICK TEST.

9) Measure EF Circuit Frequency

Reconnect IDM connector. Start engine and allow it to idle. Using New Generation Star (NGS) scan tool, select frequency meter. Use 4V DC scale. Using a jumper wire, connect test pin No. 48 of breakout box to SIG INPUT on scan tool. Using another jumper wire, connect test pin No. 77 (ground) of breakout box to COMMON on scan tool. Measure frequency at specified engine RPM. See IDM FREQUENCY SPECIFICATIONS table. If frequency is not as specified, replace IDM. Clear DTCs and repeat QUICK TEST . If frequency is as specified, replace PCM. Clear DTCs and repeat QUICK TEST.

IDM FREQUENCY SPECIFICATIONS

Engine RPM	Frequency (Hz)
1000	66
2000	133
3000	200

10) DTC P1316

This DTC indicates IDM DTCs are stored in the IDM. Injector faults are stored in the IDM and reported to PCM during KOEO ON-DEMAND SELF-TEST and KOEO INJECTOR ELECTRICAL SELF-TEST. An intermittent fault will store a DTC in the IDM. IDM DTCs are cleared by using CLEAR ALL command from the RETRIEVE/CLEAR CONTINUOUS DTCs menu on scan tool. Possible causes for this fault are:
- Faulty Injector Driver Module (IDM).
- Open or grounded circuit.
- Faulty Powertrain Control Module (PCM).
Perform KOEO ON-DEMAND SELF-TEST again. If any IDM DTCs are present, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat QUICK TEST . If no IDM DTCs are present, go to next step.

11) Verify DTC P1316 Resets

Clear Continuous Memory DTCs. Road test vehicle. Retrieve and clear Continuous Memory DTCs. Perform KOEO ON-DEMAND SELF-TEST . Retrieve DTCs. If DTC P1316 is present in continuous memory with any KOEO IDM DTCs, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat QUICK TEST . If DTC P1316 is present in continuous memory without any KOEO IDM DTCs, go to next step (if only DTC P1316 is present) or perform appropriate circuit test (if any other Continuous Memory DTCs are present).

12) Check For Open Circuit

Turn ignition off. Disconnect IDM connector. IDM is located in left side of engine compartment. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal No. 4 (Gray/White wire) at IDM connector and test pin No. 48 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 5 ohms or less, go to next step. If resistance changes to more than 5 ohms, locate and repair open circuit in Gray/White wire between PCM and IDM. Clear DTCs and repeat QUICK TEST .

13) Check For Intermittent Short To Ground

Measure resistance between ground and test pin No. 48 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 10,000 ohms or more, go to next step. If resistance changes to less than 10,000 ohms, locate and repair short to ground in Gray/White wire between PCM and IDM. Clear DTCs and repeat QUICK TEST .

14) Check For Intermittent Short To Power

Turn ignition on. Measure voltage between ground and test pin No. 48 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If no voltage is ever present, go to next step. If any voltage is present, locate and repair short to power in Gray/White wire between PCM and IDM. Clear DTCs and repeat QUICK TEST .

15) Check For Intermittent Open Circuit

Turn ignition off. Measure resistance of Brown/Orange wire between terminal No. 17 at IDM wiring harness connector and test pin No. 95 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 5 ohms or less, go to next step. If resistance changes to more than 5 ohms, locate and repair open circuit in Brown/Orange wire between PCM and IDM. Clear DTCs and repeat QUICK TEST .

16) Check For Intermittent Short To Ground

Measure resistance between ground and test pin No. 95 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If resistance stays at 10,000 ohms or more, go to next step. If resistance changes to less than 10,000 ohms, locate and repair short to ground in Brown/Orange wire between PCM and IDM. Clear DTCs and repeat QUICK TEST .

17) Check For Intermittent Short To Power

Turn ignition on. Measure voltage between ground and test pin No. 95 at breakout box. Wiggle and bend small sections of wiring harness starting at IDM connector and working toward PCM. If no voltage is ever present, go to next step. If any voltage is present, locate and repair short to power in Brown/Orange wire between PCM and IDM. Clear DTCs and repeat QUICK TEST .

18) Verify DTC P1316 Resets

Clear Continuous Memory DTCs. Road test vehicle. Retrieve and clear Continuous Memory DTCs. Perform KOEO ON-DEMAND SELF-TEST . Retrieve DTCs. If DTC P1316 is present in continuous memory with any KOEO IDM DTCs, perform appropriate circuit test and repair as necessary. Clear DTCs and repeat QUICK TEST . If DTC P1316 is present in continuous memory without any KOEO IDM DTCs, go to next step.

19) Attempt To Generate IDM DTCs

Disconnect one fuel injector connector. Start engine to generate IDM DTCs. Perform KOEO INJECTOR ELECTRICAL SELF-TEST . Perform KOEO ON-DEMAND SELF-TEST . If any IDM DTCs are present, replace PCM. Reconnect all connectors, clear DTCs and repeat QUICK TEST . If no IDM DTCs are present, replace IDM. Reconnect all connectors, clear DTCs and repeat QUICK TEST.