P2121
DTC P2121: Accelerator Pedal Position Sensor (main) Circuit Range/Performance ProblemACCELERATOR PEDAL POSITION SENSOR (MAIN) CIRCUIT RANGE/PERFORMANCE PROBLEM CIRCUIT
- Refer to, DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit.
- Refer to, DTC P0510 - Accelerator Pedal Position Switch Circuit.
CIRCUIT OPERATION
- Refer to, DTC P2122 - Accelerator Pedal Position Sensor (main) Circuit.
- Refer to, DTC P0510 - Accelerator Pedal Position Switch Circuit.
TECHNICAL DESCRIPTION
- ECM
DESCRIPTIONS OF MONITOR METHODS
- Accelerator pedal position sensor (main) output voltage is greater than that the specified value when the accelerator pedal position switch is on.
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
Logic Flow Chart:
Logic Flow Chart
Check Conditions
- Ignition switch "ON" position.
- Accelerator pedal position switch: ON
- Accelerator pedal position sensor (sub) output voltage is 2.5 volts or less.
Judgement Criterion
- Accelerator pedal position sensor (main) output voltage is 1.1 volts or higher for 1 second.
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 (main) circuit, or loose connector.
- Accelerator pedal position switch failed or maladjusted.
- Open or shorted accelerator pedal position switch circuit, or loose connector.
- 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 and accelerator pedal position switch for damage.
Q: Is the harness connector in good condition?
YES: Go to Step 2.
NO: Repair or replace it. Then go to Step 11.
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 kohm
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 measured resistance normal?
YES: Go to Step 3.
NO: Replace the accelerator pedal position sensor. Then go to Step 11.
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. Then go to Step 11.
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 11.
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 P2121 set?
YES: Replace the ECM or the PCM. Then go to Step 11.
NO: It can be assumed that this malfunction is intermittent.
STEP 7. Check the accelerator pedal position switch.
1. Disconnect the accelerator pedal position switch connector B-126.
2. Check the continuity between accelerator pedal position switch side connector terminal No. 4 and No. 5.
Standard value:
Continuity (foot released from accelerator pedal)
Non-continuity (accelerator pedal depressed)
Q: Is the switch operating properly?
YES: Go to Step 8.
NO: Replace the accelerator pedal position switch. Then go to Step 11.
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. Then go to Step 11.
STEP 9. Check for short circuit to ground between accelerator pedal position switch connector B-126 (terminal No. 4) 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 11.
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 P2121 set?
YES: Replace the ECM or the PCM. Then go to Step 11.
NO: It can be assumed that this malfunction is intermittent.
STEP 11. 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 P2121 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.