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Test DH: Throttle Position Sensor: Testing

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION  table of fault code setting condition.
FAULT CODE SETTING CONDITION

Fault Code KOEO KOER Continuous Memory
P0068    DH15  DH15
P0121    DH22  DH22
P0122  DH11  DH11  DH11
P0123  DH8  DH8  DH8
P1120  DH3  DH3  DH3
P1121  DH15  DH15  DH15
P1124  DH1  DH1  
P1125      DH20
    NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  1. 1) For KOEO & KOER Only DTC P1124: Check For Other DTCs
    DTC P1124 is set when TP sensor rotation angle or voltage reading is less than 13.27 percent (.66 volt), or is more than 23.52 percent (1.17 volt) during KOEO or KOER self-test. Possible causes for this fault are:
    • Binding Or Bent Throttle Linkage
    • TP Sensor Not Seated Properly
    • Throttle Plate Below Closed Throttle Position
    • Throttle Plate Screw Misadjusted
    • Faulty TP Sensor
    • Faulty Powertrain Control Module (PCM)

    Perform KOEO ON-DEMAND SELF-TEST and KOER ON-DEMAND SELF-TEST . Check for DTC P0405 or P1400. If DTC P0405 or P1400 is present along with P1124, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If DTC P0405 or P1400 are not present with DTC P1124, go to next step.

  2. 2) Check For Binding Throttle Plate Or Linkage

    Inspect throttle linkage and plate for binding. Ensure throttle plate is at closed position. If throttle linkage and/or plate is binding, or if throttle plate is not at closed position, repair as necessary. If throttle moves freely, opens fully and returns to closed throttle position and no mechanical concern is found, go to step  8).
    3. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  3. 3) For KOEO, KOER & Continuous Memory DTC P1120: Check For Frayed Wires Or Corrosion On Connector Terminals
    DTC P1120 is set when TP sensor rotation angle or voltage reading remains within calibrated range but falls between 3.42-9.85 percent (.17-.49 volt) during KOEO or KOER self-test. Possible causes for this fault are:
    • Frayed Or Corroded Circuit Wires Or Connectors
    • VREF Circuit Open To TP
    • VREF Circuit Shorted To SIG RTN Circuit
    • Loose Connector Or Terminals At TP Sensor

    Inspect TP sensor connector for loose, damaged or corroded terminals. Inspect wiring harness between TP sensor and PCM for damage or corrosion. Repair as necessary. If no concern is found, go to next step.

  4. 4) Check For Stuck TP Sensor

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, access TP and TP V PID from PID/DATA MONITOR & RECORD menu. While observing TP V PID, slowly move throttle plate from closed to wide open throttle position. If TP reading or (TP V) PID value indicates any sudden drop to less than 9.85 percent (.49 volt), go to next step. If TP and TP V PID readings increase and decrease gradually and smoothly, go to step  20).

  5. 5) Check Voltage Between VREF & SIG RTN Circuits To TP Sensor

    Turn ignition switch to OFF position. Disconnect TP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between VREF and SIG RTN terminals at TP sensor harness connector. See Figure, Figure and Figure . If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, reconnect TP sensor and go to TEST C, step  1).

  6. 6) Check TP Circuit For Open In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals and repair as necessary. Using a DVOM, measure resistance of TP circuit between PCM harness connector and TP sensor harness connector. See Figure, Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in TP circuit.

  7. 7) Check TP Sensor Voltage To PCM

    Reconnect PCM and TP sensor harness connector(s). Start engine and idle for 2 minutes. Using scan tool, access TP and (TP V) PID from PID/DATA MONITOR & RECORD menu. While observing TP and TP V PID, slowly open throttle. If at any time TP or (TP V) PID readings fall between 3.42-9.85 percent (.17-.49 volt), replace TP sensor. If TP or (TP V) PID readings do not fall between 3.42-9.85 percent (.17-.49 volt), repeat QUICK TEST . If DTC P1120 is still present, go to step  20).
    8. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  8. 8) For KOEO, KOER & Continuous Memory DTC P0123: Attempt To Generate Opposite TP Angle (Voltage) PID Reading
    This DTC indicates TP sensor rotation angle or voltage exceeded maximum calibrated limit during KOEO or KOER self-test. Possible causes for this fault are:
    • TP Sensor Not Seated Fully
    • TP Circuit Shorted To VPWR
    • VREF Circuit Shorted To VPWR
    • SIG RTN Circuit Open To TP Sensor
    • Faulty TP Sensor
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect TP sensor connector. Inspect connector for loose, damaged or corroded terminals and repair as necessary. Turn ignition switch to ON position. Using scan tool, access TP and TP V PID from PID/DATA MONITOR & RECORD menu. If TP or (TP V) PID readings are not less than 3.42 percent (.17 volt) or more, go to step  10). If TP or (TP V) PID readings are less than 3.42 percent (.17 volt), go to next step.

  9. 9) Check Voltage Between VREF & SIG RTN Circuits At TP Sensor

    Using a DVOM, measure voltage between VREF and SIG RTN circuits at TP sensor harness connector. See Figure, Figure and Figure . If voltage is 4-6 volts, replace TP sensor. If voltage is not 4-6 volts, reconnect components and go to TEST C, step  1).

  10. 10) Check TP Circuit For Short To VREF Or VPWR Circuits

    Turn ignition switch to OFF position. Leave TP sensor disconnected. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals and repair as necessary. Using a DVOM, measure resistance between TP circuit, VPWR and VREF circuits at PCM harness connector. Both VREF circuits on 150-pin PCM models. If any resistance measurement is 10 k/ohms or less, repair short between circuits. If all resistance measurements are more than 10 k/ohms, replace PCM.
    11. NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    NOTE: An intermittent fault can cause a Continuous Memory DTC P0122. If a Continuous Memory DTC P0122 is still present after performing steps  11)- 14) , go to TEST Z, step 1) for intermittent testing.
    NOTE: If a scan tool communication concern exists, remove jumper wire and go to step  14).

  11. 11) For KOEO, KOER & Continuous Memory DTC P0122: Attempt To Generate Opposite TP Angle (Voltage) PID Reading
    This DTC indicates TP sensor rotation angle or voltage fell below minimum calibrated limit during KOEO or KOER self-test. Possible causes for this fault are:
    • TP Sensor Not Seated Fully
    • TP Circuit Open To PCM
    • VREF Circuit Open To TP Sensor
    • TP Circuit Shorted To SIG RTN Or GND
    • Faulty TP Sensor
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect TP sensor connector. Inspect connector for loose, damaged or corroded terminals and repair as necessary. Connect a jumper wire between VREF and TP circuits at TP sensor harness connector. Turn ignition switch to ON position.

    Using scan tool, access TP and (TP V) PID from PID/DATA MONITOR & RECORD menu. If TP or (TP V) PID readings are more than 9.3 percent (4.65 volts), replace TP sensor. If TP or (TP V) PID readings are 9.3 percent (4.65 volts) or less, remove jumper wire and go to next step.

  12. 12) Check Voltage Between VREF & SIG RTN Circuits

    Turn ignition switch to ON position. Using a DVOM, measure voltage between VREF and SIG RTN circuits at TP sensor harness connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, reconnect sensor and go to TEST C, step  1).

  13. 13) Check TP Circuit For Open In Harness

    Turn ignition switch to OFF position. Leave TP sensor disconnected. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals and repair as necessary. Using a DVOM, measure resistance of TP circuit between PCM harness connector and TP sensor harness connector. See Figure, Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in TP circuit.

  14. 14) Check TP Circuit For Short To SIG RTN Or PWR GND In Harness

    Ensure PCM is disconnected. Disconnect scan tool from Data Link Connector (DLC). Using a DVOM, measure resistance between TP circuit, and SIG RTN and PWR GND circuits at PCM harness connector. If either resistance measurement is 10 k/ohms or less, repair short between circuits. If both resistance measurements are more than 10 k/ohms, replace PCM.
    15. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  15. 15) For KOER & Continuous Memory Only DTCs P0068 & P1121: Check Rationality Operation Between TP & MAF Sensors
    This DTC is set when the comparison between TP and MAF sensor readings are not consistent with calibrated load values during KOER self-test. Possible causes for this fault are:
    • Air Leak Between MAF Sensor & Throttle Body
    • TP Sensor Not Seated Fully
    • Faulty TP Sensor
    • Faulty MAF Sensor

    Attempt to start engine. If engine starts, go to next step. If engine does not start, check for cracks or openings in air induction system between MAF sensor and throttle body. Repair as necessary. If air induction system is okay, go to TEST A, step  1).

  16. 16) Check Mechanical Operation Of TP Sensor

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, access TP and (TP V) PID from PID/DATA MONITOR & RECORD menu. While observing TP and (TP V) PID readings, slowly move throttle from closed position to wide open throttle position. If TP or (TP V) PID readings change from 9.85-93.00 percent (.49-4.65 volts), go to next step. If TP or (TP V) PID readings do not change from 9.85-93.00 percent (.49-4.65 volts), replace TP sensor. Repeat QUICK TEST to verify repair.

  17. 17) Check TP Sensor Signal High Versus Engine Load While Driving Vehicle

    Drive vehicle (vary throttle position) while selecting TP, (TP V) and LOAD PIDs from PID/DATA MONITOR & RECORD menu. If TP or (TP V) PID readings are 49.02 percent (2.44 volts) or less, and LOAD PID reading is 30 percent or more, go to next step. If TP or (TP V) PID readings are more than 49.02 percent (2.44 volts), and LOAD PID value is less than 30 percent, check for cracks or openings in air induction system between MAF sensor and throttle body. If air induction is restricted, go to TEST HU, step 1) and repair as necessary. If air induction system is okay, replace TP sensor.

  18. 18) Check TP Sensor Signal Low Versus Engine Load While Driving Vehicle

    Start engine and allow to idle. If engine is a no-start, go to TEST A, step  1). Drive vehicle (vary throttle position) in higher gears (preferably Overdrive) while selecting TP, TP V and LOAD PID from PID/DATA MONITOR & RECORD menu. If TP or (TP V) PIDs are 4.82 percent (.24 volt) or more, and LOAD PID is 55 percent or less, fault is intermittent and cannot be duplicated at this time. Testing is complete. If TP or (TP V) PIDs are less than 4.82 percent (.24 volt), and LOAD PID is more than 55 percent, tighten TP sensor (if necessary). Clear DTCs. Road test vehicle ensuring throttle is operated through all phases. Perform QUICK TEST . If Continuous Memory DTC P1121 is still present, replace MAF sensor.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 18) to step 20). No test procedures have been omitted.
    19. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  19. 20) For Continuous Memory Only DTC P1125: Check For Intermittent TP Circuit Signal
    These DTCs are set when TP sensor voltage reading falls below minimum calibrated range of .49 volt or exceeds maximum calibrated range of 4.65 volts during the last 80 drive cycles. Possible causes for this fault are:
    • Poor Continuity Through TP Sensor Wiring Harness Or Connector
    • Intermittent Open Or Short In TP Sensor

    Ensure scan tool is connected to Data Link Connector (DLC). Start engine and allow to idle. Raise engine speed to 1500 RPM for 5 seconds and return to idle. Using scan tool, access TP and TP V PID from PID/DATA MONITOR & RECORD menu. While observing TP and TP V PID, lightly tap on TP sensor and wiggle sensor connector and wiring harness to simulate road shock. If TP or (TP V) PID readings stay within normal operating range of 9.85-93.00 percent (.49-4.65 volts), go to next step. If TP or (TP V) PID readings do not stay within normal operating range of 9.85-93.00 percent (.49-4.65 volts), inspect TP sensor installation and connector. Repair as necessary and retest. If TP sensor installation and connector are okay, replace TP sensor.

  20. 21) Check TP Sensor Harness For Intermittent Opens Or Shorts

    Turn ignition switch to OFF position. Using scan tool, access TP and TP V PIDs from PID/DATA MONITOR & RECORD menu. Turn ignition switch to ON position. While observing TP and TP V PIDs, wiggle small sections of wiring harness starting at TP sensor working toward PCM. If TP or (TP V) PID readings stay within normal operating range of 9.85-93.00 percent (.49-4.65 volts), concern is intermittent and cannot be identified at this time. Go to TEST Z, step 1) . If TP or (TP V) PID readings do not stay within normal operating range of 9.85-93.00 percent (.49-4.65 volts), isolate fault and repair as necessary.
    21. NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    CAUTION: DO NOT clean throttle bore or plate area. Cleaning will damage throttle body assembly.

  21. 22) For KOER & Continuous Memory Only DTC P0121: Isolate Binding Or Sticking Concern
    Disconnect accelerator and speed control cables from throttle body linkage. Rotate linkage on throttle body. If sticking, binding or grabbing is felt when rotating throttle body linkage, replace throttle body assembly. If throttle body linkage rotates freely without sticking, binding or grabbing, replace faulty cable(s). Repeat QUICK TEST . If DTC P0121 is still present, go to next step.

  22. 23) Check Functionality Of TP Sensor

    Turn ignition switch to ON position. Using scan tool, access TP V PID from PID/DATA MONITOR & RECORD menu. While observing TP V PID voltage, slowly move throttle through range from closed position to wide open throttle. If TP V PID voltage increases smoothly during throttle movement, concern cannot be identified at this time. If TP V PID voltage does not increase smoothly during throttle movement, turn ignition switch to OFF position and replace TP sensor.
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