DH: Throttle Position (TP) Sensor

DH: Introduction See: DH: Throttle Position (TP) Sensor - Introduction

DH1 KOEO AND KOER DTC P1124: CHECK FOR OTHER DTCS

• Check for DTC P1400 in KOEO or KOER Self-Test.

Is KOEO or KOER DTC P1400 present with KOEO DTC P1124?
Yes

• RETURN to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptionsfor

DTC P1400.

No

• KEY OFF. GO to DH2

.

DH2 CHECK FOR STUCK THROTTLE PLATE OR LINKAGE

• Visually inspect the throttle linkage and throttle plate for binding or sticking.
• Verify the throttle plate and linkage is at closed throttle position.

Does the throttle move freely and return to closed throttle position?
Yes

• Throttle plate and linkage are OK. GO to DH8

.

No

• REPAIR as necessary.

DH3 DTC P1120: CHECK TP CIRCUIT FOR FRAYED WIRES OR CORROSION ON CONNECTORS

• Key off.
• Complete a visual inspection of pins on harness connector at the TP sensor for corrosion.
• Complete a visual inspection of the harness wires between the TP sensor and the PCM for insulation fraying and corrosion.

Is a fault present?
Yes

• REPAIR as necessary.

No

• GO to DH4

.

DH4 CHECK FOR STUCK TP SENSOR

• Key on, engine off.
• Access TP PID (TP V PID).
• Slowly move throttle from closed throttle position to wide open throttle position and observe the TP PID (TP V PID).

While opening the throttle, is the TP PID (TPV PID) reading below 9.85% (0.49 volt)?
Yes

• KEY OFF. GO to DH5

.

No

• GO to DH20

.

DH5 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS TO TP SENSOR

• Disconnect TP sensor.
• Key on, engine off.
• Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.

Is voltage between 4.0 and 6.0 volts?
Yes

• KEY OFF. GO to DH6

.

No

• GO to C1 See: C: Reference Voltage - Pinpoint Test

.

DH6 CHECK TP CIRCUIT FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Measure resistance of TP circuit between PCM harness connector pin and TP harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to DH7

.

No

• REPAIR open circuit.

DH7 CHECK TP SENSOR VOLTAGE TO PCM

• Reconnect PCM and TP sensor.
• Start engine and idle for 2 minutes.
• Access TP PID (TP V PID).
• Slowly open the throttle from closed position and observe PID(s).

Is TP PID (TP V PID) reading at any time between 3.42-9.85% (0.17-0.49 volt)?
Yes

• REPLACE TP sensor.

No

• If DTC P1120 is still present, GO to DH20

.

DH8 DTC P0123 OR P1124: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING

• Disconnect TP sensor.
• Key on, engine off.
• Access TP PID (TP V PID).

Is TP PID (TP V PID) less than 3.42% (0.17 volt)?
Yes

• GO to DH9

.

No

• KEY OFF. GO to DH10

.

DH9 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS TO TP SENSOR

• Key on, engine off.
• Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.

Is voltage between 4.0 and 6.0 volts?
Yes

• REPLACE TP sensor.

No

• GO to C1 See: C: Reference Voltage - Pinpoint Test

.

DH10 CHECK TP CIRCUIT FOR SHORT TO VREF OR VPWR IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Measure resistance between TP and VPWR circuits at the PCM harness connector.
• Measure resistance between TP and VREF circuits at the PCM harness connector. (For 150PIN PCM, measure to both VREF pins.)

Is each resistance greater than 10,000 ohms?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• REPAIR short circuit.

DH11 DTC P0122: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING

Note: An intermittent fault can cause a Continuous Memory DTC P0122. If a Continuous Memory DTC P0122 is still present after DH11 through DH14,GO to DH20.

• Disconnect TP sensor.
• Jumper VREF circuit to TP circuit at the TP sensor harness connector.
• Key on, engine off.

Note: If any scan tool communication concern exists, remove jumper and GO to DH14.

• Access TP PID (TP V PID).

Is TP PID (TP V PID) greater than 93% (4.65 volts)?
Yes

• REPLACE TP sensor.

No

• REMOVE jumper. GO to DH12

.

DH12 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS

• Key on, engine off.
• Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.

Is voltage between 4.0 and 6.0 volts?
Yes

• KEY OFF. GO to DH13

.

No

• GO to C1 See: C: Reference Voltage - Pinpoint Test

.

DH13 CHECK TP SENSOR CIRCUIT FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM.
• Measure resistance of TP circuit between PCM harness connector pin and TP sensor harness connector.

Is resistance less than 5.0 ohms?
Yes

• GO to DH14

.

No

• REPAIR open circuit.

DH14 CHECK TP CIRCUIT FOR SHORT TO PWR GND OR SIG RTN IN HARNESS

• Disconnect PCM.
• Disconnect scan tool from DLC.
• Measure resistance between TP and PWR GND circuits at the PCM harness connector.
• Measure resistance between TP and SIG RTN circuits at the PCM harness connector.

Are both resistances greater than 10,000 ohms?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• REPAIR short circuit.

DH15 DTC P1121: CHECK RATIONALITY OPERATION BETWEEN TP AND MAF SENSORS

• Attempt to start engine.

Does the engine run?
Yes

• GO to DH16

.

No

• CHECK for major leaks, cracks, and openings between MAF sensor

and throttle body. If OK, GO to A1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\A: No Start - Pinpoint Test
.

DH16 CHECK MECHANICAL OPERATION OF TP SENSOR

• Key on, engine off.
• Access TP PID (TP V PID).
• Slowly move throttle from closed throttle position to wide open throttle position.
• Observe and record the TP PID (TP V PID).

While opening and closing the throttle, is there a change in the TP PID (TP V PID) between 9.85% and 93% (0.49 and 4.65 volts)?
Yes

• GO to DH17

.

No

• REPLACE TP sensor. VERIFY a symptom no longer exists.

DH17 CHECK TP SENSOR SIGNAL HIGH VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE

• Key on, engine running.
• Drive vehicle, exercising the throttle and TP sensor while accessing PIDS.
• Access TP PID (TP V PID) and LOAD PID and record readings.

Is TP PID (TP V PID) greater than 49.02% (2.44 volts) and the LOAD PID reading less than 30%?
Yes

• LISTEN for air noise around MAF sensor and throttle body while

engine is running. REPAIR if necessary. Otherwise, GO to HU1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\HU: Intake Air Systems - Pinpoint Test
for
air restriction. If OK, REPLACE the TP sensor.

No

• GO to DH18

.

DH18 CHECK TP SENSOR SIGNAL LOW VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE

Note: If the vehicle is a no start, GO to A1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\A: No Start - Pinpoint Test.

• Drive vehicle exercising the throttle and TP sensor near higher gears (preferably overdrive) while accessing PIDS.
• Access TP PID (TP V PID) and LOAD PID.

Is TP PID (TP V PID) reading less than 4.82% (0.24 volts) and the LOAD PID reading greater than 55%?
Yes

• TIGHTEN TP sensor to throttle body if necessary. CLEAR Continuous

Memory DTCs. DRIVE vehicle exercising the throttle. If Continuous Memory P1121
is now present, REPLACE MAF sensor.

No

• Unable to identify the fault at this time. If vehicle is still

a No Start, GO to A1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\A: No Start - Pinpoint Test
.

DH20 CONTINUOUS MEMORY DTCS P1120 OR P1125: CHECK FOR TP CIRCUIT INTERMITTENT SIGNAL

• Start engine and bring to idle.
• Run throttle up to 1500 rpm for 5 seconds.
• Access TP PID (TP V PID) for a fault indication while completing the following:
• Lightly tap on TP sensor and wiggle harness connector to simulate road shock.

Is TP PID (TP V PID) changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes

• INSPECT the TP sensor connector. If OK, REPLACE the TP sensor.

No

• KEY OFF. GO to DH21

.

DH21 CHECK TP SENSOR HARNESS FOR INTERMITTENT OPENS OR SHORTS

• Again access the TP PID (TP V PID).
• Key on, engine off.
• Complete the following:
• Grasp the vehicle harness closest to the TP sensor connector.
• Shake and bend a small section of the harness all the way to the dash panel.
• Wiggle, shake and bend the harness from the dash panel to the PCM.

Is TP PID (TP V PID) reading changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes

• ISOLATE and REPAIR as necessary.

No

• Unable to duplicate or identify fault at this time. GO to Z1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test

.

DH22 DTC P0121: CHECK FOR KOER SELF-TEST COMPLETION

Note: If KOER Self-Test terminates when placing the transmission range selector lever in gear (DRIVE or REVERSE), GO to DH25 directly.

• Start engine, bring to idle (throttle closed).
• Activate Key On Engine Running (KOER) Self-Test.
• Attempt to drive vehicle, while still in Key On Engine Running Self-Test.
• Key off, wait 15 seconds.
• Start engine again.
• Activate KOER Self-Test.

Is DTC P0121 still present or does KOER Self-Test again fail to terminate?
Yes

• KEY OFF. GO to DH23

.

No

• VERIFY a symptom no longer exists.

DH23 ISOLATE BINDING OR STICKING CONCERN

• Disconnect accelerator cable and speed control cable from throttle body linkage.

• Rotate throttle body linkage.

Does the throttle body rotate freely without a sticking, binding or grabbing condition?
Yes

• REPAIR cable(s) causing concern. RERUN Quick Test. If the DTC

P0121 is still present, GO to DH24
.

No

• REPLACE throttle body assembly.

DH24 CHECK FUNCTIONALITY OF THE THROTTLE POSITION SENSOR

• Key on.
• Access TP V PID with the scan tool.
• From closed throttle, slowly begin to press accelerator to wide open throttle.

Did the TP V PID display a smooth reading during accelerator movement?
Yes

• VERIFY a symptom no longer exists.

No

• KEY OFF. REPLACE TP sensor.

DH25 CHECK TP AND SIG RTN CIRCUITS FOR OPEN IN HARNESS

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect PCM and TP sensor.
• Key off.
• Measure resistance of TP circuit between PCM harness connector and TP sensor harness connector.
• Measure resistance of SIG RTN circuit between PCM harness connector and TP sensor harness connector.

Is each resistance less than 0.5 ohms?
Yes

• REPLACE TP sensor. VERIFY a symptom no longer exists.

No

• REPAIR open circuit. VERIFY a symptom no longer exists.