P0111
Connectors:
CIRCUIT OPERATION
- Approximately 5 volts are applied to the intake air temperature sensor output terminal (terminal 6) from the ECM (terminal 62)
- The intake air temperature sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
- The intake air temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.
TECHNICAL DESCRIPTION
- The intake air temperature sensor converts the intake air temperature to a voltage.
- The ECM
DTC SET CONDITIONS
Check Conditions
- Two seconds or more have passed since the engine was started.
Judgement Criteria
- Intake air temperature sensor output voltage has continued to be 4.6 volts or higher [corresponding to an air intake temperature of -45 °C (-49 °F) or lower) for 2 seconds.
or
- Intake air temperature sensor output voltage has continued to be 0.2 volt or lower [corresponding to an air intake temperature of 125 °C (257 °F) or higher] for 2 seconds.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Intake air temperature sensor failed.
- Open or shorted intake air temperature sensor circuit, or loose connector.
- ECM failed.
DIAGNOSIS
Required Special Tools
MB991502: Scan Tool(MUT-II)
STEP 1. Using scan tool MB991502, check data list item 13: Intake Air Temperature 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 13, Intake Air Temperature Sensor.
- The intake air temperature and temperature shown with the scan tool should approximately match.
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 the sensor output voltage at intake air temperature sensor connector B-14 by backprobing.
1. Do not disconnect the connector B-14.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 6 and ground by backprobing.
- When intake air temperature is 0 °C (32 °F), voltage should be 3.2 and 3.8 volts.
- When intake air temperature is 20 °C (68 °F), voltage should be 2.3 and 2.9 volts.
- When intake air temperature is 40 °C (104 °F), voltage should be 1.5 and 2.1 volts.
- When intake air temperature is 80 °C (176 °F), voltage should be 0.4 and 1.0 volts.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the voltage normal?
YES: Go to Step 3.
NO: Go to Step 5.
STEP 3. Check connector B-14 at the intake air temperature sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 4.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 19.
STEP 4. Using scan tool MB991502, check data list item 13: Intake Air Temperature 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 13, Intake Air Temperature Sensor.
- The intake air temperature and temperature shown with the scan tool should approximately match.
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 19.
STEP 5. Check connector B-14 at intake air temperature sensor for damage.
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 19.
STEP 6. Check the intake air temperature sensor.
1. Disconnect the intake air temperature sensor connector B1
2. Measure the resistance between intake air temperature sensor side connector terminal 5 and 6.
- There should be continuity. (0.30 - 1.0 kOhms)
NOTE: Check that the circuit is not open loop.
Q: Is the resistance normal?
YES: Go to Step 7.
NO: Replace the volume air flow sensor. Then go to Step 19.
STEP 7. Check the sensor supply voltage at intake air temperature sensor harness side connector B-14.
1. Disconnect the connector B-14 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 6 and ground.
- Voltage should be between 4.8 and 5.2 volts.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the voltage normal?
YES: Go to Step 12.
NO: Go to Step 8.
STEP 8. Check the sensor supply voltage at ECM connector C-118
1. Do not disconnect the ECM connector C-118
2. Disconnect the intake air temperature sensor connector B-14.
3. Turn the ignition switch to the "ON" position.
4. Measure the voltage between terminal 62
- Voltage should be between 4.8 and 5.2 volts.
5. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the voltage normal?
YES: Go to Step 9.
NO: Go to Step 10.
STEP 9. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Repair harness wire between intake air temperature sensor connector B-14 terminal 6 and ECM connector C-118 terminal 62
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 19.
STEP 10. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Go to Step 11.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 19.
STEP 11. Check for short circuit to ground between intake air temperature sensor connector B-14 terminal 6 and ECM connector C-118 terminal 62
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 19.
NO: Repair it. Then go to Step 19.
STEP 12. Check the continuity at intake air temperature sensor harness side connector B-14.
1. Disconnect the connector B-14 and measure at the harness side.
2. Check for the continuity between terminal 5 and ground. Should be less than 2 Ohms.
Q: Is the continuity normal?
YES: Go to Step 15.
NO: Go to Step 13.
STEP 13. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Go to Step 14.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 19.
STEP 14. Check for open circuit and harness damage between intake air temperature sensor connector B-14 terminal 5 and ECM connector C-118 terminal 49
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 19.
NO: Repair it. Then go to Step 19.
STEP 15. Check the intake air temperature sensor.
1. Disconnect the intake air temperature sensor connector B-14
2. Measure the resistance between intake air temperature sensor side connector terminal 5 and 6.
3. Measure resistance while heating the sensor using a hair drier.
Standard value:
5.3 - 6.7 kOhms (at 0 °C (32 °F)]
2.3 - 3.0 kOhms [at 20 °C (68 °F)]
1.0 - 1.5 kOhms [at 40 °C (104 °F)]
0.30 - 0.42 kOhms [at 80 °C (176 °F)]
Q: Is the resistance at the standard value?
YES: Go to Step 16.
NO: Replace the volume air flow sensor. Then go to Step 19.
STEP 16. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Go to Step 17.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 19.
STEP 17. Check for harness damage between intake air temperature sensor connector B-14 terminal 5 and ECM connector C-118 terminal 49
Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair it. Then go to Step 19.
STEP 18. Check for harness damage between intake air temperature sensor connector B-14 terminal 6 and ECM connector C-118 terminal 62
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 19.
NO: Repair it. Then go to Step 19.
STEP 19. 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 P0111 is output?
YES: Retry the troubleshooting.
NO: The inspection is complete.