P0122
CIRCUIT OPERATION
- A 5-volt power supply is applied on the TPS power terminal (terminal 4) from the ECM (terminal 42)
- When the throttle valve shaft is turned from the idle position to the fully opened position, the resistor between the TPS output terminal (terminal 3) and ground terminal will increase according to the rotation.
TECHNICAL DESCRIPTION
- The TPS outputs voltage which corresponds to the throttle valve opening angle.
- The ECM
DTC SET CONDITIONS
Check Conditions
- Two seconds or more have passed since the staring sequence was completed.
- Engine speed is higher than 2,000 r/min.
- Volumetric efficiency is higher than 60 percent.
Judgement Criteria
- TPS output voltage has continued to be 0.8 volt or lower for 2 seconds.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- TPS failed or maladjusted.
- Open or shorted TPS circuit, or loose connector.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tools
MB991502: Scan Tool(MUT-II)
STEP 1. Using scan tool MB991502, check data list item 14: Throttle Position Sensor.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK"(OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to the data reading mode for item 14, Throttle Position Sensor.
- With the throttle valve in the idle position, voltage should be between 0.535 and 0.735 volts.
- With the throttle valve in the full-open position, voltage should be between 4.5 and 5.5 volts.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.
NO: Go to Step 2.
STEP 2. Check connector B-07 at throttle position sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 9.
STEP 3. Check the throttle position sensor.
1. Disconnect the connector B-07.
2. Measure the resistance between throttle position sensor side connector terminal 1 and 4.
Standard value: 3.5 - 6.5 kOhms
3. Measure resistance between the throttle position sensor side connector terminal 1 and 3.
4. Move the throttle valve from the idle position to the full-open position.
- Resistance should change smoothly in proportion to the opening angle of the throttle valve.
Q: Is the resistance normal?
YES: Go to Step 4.
NO: Replace the throttle position sensor. Then go to Step 9.
STEP 4. Check the maladjusted throttle position sensor.
Q: Is the output voltage normal?
YES: Go to Step 5.
NO: Adjust it. Then go to Step 9.
STEP 5. Check connector C-122 at ECM
Q: Is the connector in good condition?
YES: Go to Step 6.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 9.
STEP 6. Check for harness damage between throttle position sensor connector B-07 terminal 4 and ECM connector C-118 terminal 42
Q: Is the harness wire in good condition?
YES: Go to Step 7.
NO: Repair it. Then go to Step 9.
STEP 7. Check for harness damage between throttle position sensor connector B-07 terminal 3 and ECM connector C-122 terminal 78
Q: Is the harness wire in good condition?
YES: Go to Step 8.
NO: Repair it. Then go to Step 9.
STEP 8. Using scan tool MB991502, check data list item 14: Throttle Position Sensor.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK"(OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991502 to the data reading mode for item 14, Throttle Position Sensor.
- With the throttle valve in the idle position, voltage should be between 0.535 and 0.735 volts.
- With the throttle valve in the full-open position, voltage should be between 4.5 and 5.5 volts.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points.
NO: Replace the ECM or PCM. Then go to Step 9.
STEP 9. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code(DTC).
Q: Is the DTC P0122 is output?
YES: Retry the troubleshooting.
NO: The inspection is complete.