P2138
DTC P2138: Accelerator Pedal Position Sensor (main and sub) Circuit Range/Performance ProblemACCELERATOR PEDAL POSITION SENSOR (MAIN AND SUB) RANGE/PERFORMANCE PROBLEM CIRCUIT
- Refer to DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit.
- Refer to DTC P2127 - Accelerator Pedal Position Sensor (sub) Circuit.
CIRCUIT OPERATION
- Refer to DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit.
- Refer to DTC P2127 - Accelerator Pedal Position Sensor (sub) Circuit.
TECHNICAL DESCRIPTION
- ECM
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)
- Not applicable
Sensor (The sensor is determined to be normal)
- Not applicable
DTC SET CONDITIONS
Logic Flow Chart:
Logic Flow Chart
Check Condition
- Ignition switch is "ON" position.
- Accelerator pedal position sensor (main) output voltage is between 0.2 and 4.5 volts.
- Accelerator pedal position sensor (sub) output voltage is between 0.2 and 4.5 volts.
- Change of accelerator pedal position sensor (sub) output voltage per 25 milliseconds is lower than 0.1 volt.
Judgement Criteria
- Accelerator pedal position sensor (sub) output voltage minus accelerator pedal position sensor (main) output voltage should be 1 volt or higher for 1 second.
- Accelerator pedal position sensor (main) output voltage minus accelerator pedal position sensor (sub) output voltage should be 1 volt or higher for 0.2 seconds.
OBD-II DRIVE CYCLE PATTERN
None.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Accelerator pedal position sensor failed or maladjusted.
- Open or shorted accelerator pedal position sensor circuit, or connector damage.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
STEP 1. Check harness connector B-126 at accelerator pedal position sensor for damage.
Q: Is the harness connector in good condition?
YES: Go to Step 2.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 17.
STEP 2. Check the accelerator pedal position sensor.
1. Disconnect the accelerator pedal position sensor connector B-126.
2. Measure resistance between terminal No.1 and No. 2 and between terminal No. 7 and No. 8.
Standard value: 3.5 - 6.5 kOhms
3. Measure resistance between terminal No. 2 and No. 3 and between terminal No. 6 and No. 8 when the accelerator pedal is gently depressed from idle position to the full open position.
- Resistance value changes in accordance with the accelerator pedal depression smoothly.
Q: Is the resistance normal?
YES: Go to Step 3.
NO: Replace the accelerator pedal position sensor. Then go to Step 17.
STEP 3. Check the continuity at accelerator pedal position sensor harness side connector B-126.
1. Disconnect the connector B-126 and measure at the harness side.
2. Measure the continuity between terminal No. 1 and ground.
- Should be less than 2 Ohms.
Q: Does continuity exist?
YES: Go to Step 7.
NO: Go to Step 4.
STEP 4. Check harness connector C-139 at ECM
Q: Is the harness connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 17.
STEP 5. Check for harness damage between accelerator pedal position sensor connector B-126 (terminal No. 1) and ECM connector C-139
Q: Is the harness wire in good condition?
YES: Go to Step 6.
NO: Repair it. Then go to Step 17.
STEP 6. Using scan tool MB991958, read the diagnostic trouble code (DTC).
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. 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 or PCM. Then go to Step 17.
NO: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.
STEP 7. Check the continuity at accelerator pedal position sensor harness side connector B-126.
1. Disconnect the connector B-126 and measure at the harness side.
2. Measure the continuity between terminal No. 7 and ground.
- Should be less than 2 Ohms.
Q: Does continuity exist?
YES: Go to Step 11.
NO: Go to Step 8.
STEP 8. Check harness connector C-139 at ECM
Q: Is the harness connector in good condition?
YES: Go to Step 9.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 17.
STEP 9. Check for harness damage between accelerator pedal position sensor connector B-126 (terminal No. 7) and ECM connector C-139
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).
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. 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 or PCM. Then go to Step 17.
NO: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.
STEP 11. Check harness connector C-139 at ECM
Q: Is the harness connector in good condition?
YES: Go to Step 12.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 17.
STEP 12. Check for harness damage between accelerator pedal position sensor connector B-126 (terminal No. 2) and ECM connector C-139
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 B-126 (terminal No. 8) and ECM connector C-139
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 B-126 (terminal No. 3) and ECM connector C-139
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 B-126 (terminal No. 6) and ECM connector C-139
Q: Is the harness wire in good condition?
YES: Go to Step 16.
NO: Repair it. Then go to Step 17.
STEP 16. Using scan tool MB991958, read the diagnostic trouble code (DTC).
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. 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 or PCM. Then go to Step 17.
NO: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.
STEP 17. Using scan tool MB991958, read the diagnostic trouble code (DTC).
1. Connect scan tool MB991958 to the data link connector.
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: Retry the troubleshooting.
NO: The inspection is complete.