P2138

DTC P2138: Accelerator Pedal Position Sensor (Main And Sub) Range/Performance Problem

ACCELERATOR PEDAL POSITION SENSOR (main and sub) RANGE/PERFORMANCE PROBLEM CIRCUIT
- Refer to DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit Low Input. P2122
- Refer to DTC P2127 - Accelerator Pedal Position Sensor (sub) Circuit Low Input. P2127

CIRCUIT OPERATION
- Refer to DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit Low Input. P2122
- Refer to DTC P2127 - Accelerator Pedal Position Sensor (sub) Circuit Low Input. P2127

TECHNICAL DESCRIPTION
- ECM checks the accelerator pedal position sensor output signal characteristics for abnormal conditions.

DESCRIPTIONS OF MONITOR METHODS
Detect malfunction if the relation between accelerator pedal position sensor (main) and accelerator pedal position sensor (sub) is wrong.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable

Sensor (The sensor below is determined to be normal)
- Not applicable

DTC SET CONDITIONS [Range/Performance problem -relation between main and sub]

Check Condition
- Change of accelerator pedal position sensor (sub) output voltage per 25 milliseconds is less than 0.06 volt.

Judgement Criterion
- The accelerator pedal position sensor (sub) output voltage subtracted from the accelerator pedal position sensor (main) output voltage is more than 0.4 volt for 0.2 second.

NOTE: The accelerator pedal position sensor voltage used for the judgement is converted into the accelerator pedal position sensor voltage for the internal processing by the ECM.

FAIL-SAFE AND BACKUP FUNCTION
- Throttle opening degree is restricted.
- Throttle opening degree position is in default position if accelerator pedal position sensor (sub) fails.

OBD-II DRIVE CYCLE PATTERN
None.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Accelerator pedal position sensor failed.
- Harness damage in accelerator pedal position sensor circuit or connector damage.
- ECM failed.

DIAGNOSIS

Required Special Tool:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Using scan tool MB991958, check data list item 11: Accelerator Pedal Position Sensor (main).

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to the data reading mode for item 11, Accelerator Pedal Position Sensor (main).
- Output voltage should be between 900 and 1,100 millivolts when foot is released from accelerator pedal.
- Output voltage should be 4,000 millivolts or more when accelerator pedal is fully depressed.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 2.

NO : Refer to, DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit Low Input, P2122 DTC P2123 - Accelerator Pedal Position Sensor (main) Circuit High Input. P2123

STEP 2. Using scan tool MB991958, check data list item 12: Accelerator Pedal Position Sensor (sub).

1. Turn the ignition switch to the "ON" position.
2. Set scan tool MB991958 to the data reading mode for item 12, Accelerator Pedal Position Sensor (sub).
- Output voltage should be between 400 and 600 millivolts when foot is released from accelerator pedal.
- Output voltage should be 2,000 millivolts or more when accelerator pedal is fully depressed.

3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 3.

NO : Refer to, DTC P2127 - Accelerator Pedal Position Sensor (sub) Circuit Low Input, P2127 DTC P2128 - Accelerator Pedal Position Sensor (sub) Circuit High Input. P2128

STEP 3. Check harness connector C-123 at accelerator pedal position sensor for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 4.

NO : Repair or replace it. Then go to Step 17.

STEP 4. Check the continuity at accelerator pedal position sensor harness side connector C-123.

1. Disconnect the connector C-123 and measure at the harness side.

2. Check for the continuity between terminal No. 2 and ground.
- Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 7.

NO : Go to Step 5.

STEP 5. Check harness connector B-109 at ECM for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 6.

NO : Repair or replace it. Then go to Step 17.

STEP 6. Check for harness damage between accelerator pedal position sensor connector C-123 (terminal No. 2) and ECM connector B-109 (terminal No. 76).

Q: Is the harness wire in good condition?

YES : Go to Step 10.

NO : Repair it. Then go to Step 17.

STEP 7. Check the continuity at accelerator pedal position sensor harness side connector C-123.

1. Disconnect the connector C-123 and measure at the harness side.

2. Check for the continuity between terminal No. 5 and ground.
- Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 11.

NO : Go to Step 8.

STEP 8. Check harness connector B-109 at ECM for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 9.

NO : Repair or replace it. Then go to Step 17.

STEP 9. Check for harness damage between accelerator pedal position sensor connector C-123 (terminal No. 5) and ECM connector B-109 (terminal No. 79).

Q: Is the harness wire in good condition?

YES : Go to Step 10.

NO : Repair it. Then go to Step 17.

STEP 10. Using scan tool MB991958, read the diagnostic trouble code (DTC).

1. Turn the ignition switch to the "ON" position.
2. After the DTC has been deleted, read the DTC again.
3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P2138 set?

YES : Replace the ECM. Then go to Step 17.

NO : It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions. Troubleshooting Contents

STEP 11. Check harness connector B-109 at ECM for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 12.

NO : Repair or replace it. Then go to Step 17.

STEP 12. Check for harness damage between accelerator pedal position sensor connector C-123 (terminal No. 1) and ECM connector B-109 (terminal No. 75).

Q: Is the harness wire in good condition?

YES : Go to Step 13.

NO : Repair it. Then go to Step 17.

STEP 13. Check for harness damage between accelerator pedal position sensor connector C-123 (terminal No. 4) and ECM connector B-109 (terminal No. 78).

Q: Is the harness wire in good condition?

YES : Go to Step 14.

NO : Repair it. Then go to Step 17.

STEP 14. Check for harness damage between accelerator pedal position sensor connector C-123 (terminal No. 3) and ECM connector B-109 (terminal No. 74).

Q: Is the harness wire in good condition?

YES : Go to Step 15.

NO : Repair it. Then go to Step 17.

STEP 15. Check for harness damage between accelerator pedal position sensor connector C-123 (terminal No. 6) and ECM connector B-109 (terminal No. 77).

Q: Is the harness wire in good condition?

YES : Go to Step 16.

NO : Repair it. Then go to Step 17.

STEP 16. Replace the accelerator pedal assembly.

1. Replace the accelerator pedal assembly.
2. Turn the ignition switch to the "ON" position.
3. After the DTC has been deleted, read the DTC again.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P2138 set?

YES : Replace the ECM. Then go to Step 17.

NO : The inspection is complete.

STEP 17. Using scan tool MB991958, read the diagnostic trouble code (DTC).

1. Turn the ignition switch to the "ON" position.
2. After the DTC has been deleted, read the DTC again.
3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P2138 set?

YES : Retry the troubleshooting.

NO : The inspection is complete.