DTC 11

DTC 11: Interior Temperature Sensor system

Interior Temperature Sensor Circuit:

DTC SET CONDITION
- DTC 11 is set if there is a defective connector connection, or if there is an open circuit in the harness.
- DTC 12 is set if there is a short circuit in the interior temperature sensor input circuit.

TROUBLESHOOTING HINT
- Malfunction of connector.
- Malfunction of the harness.
- Malfunction of the interior temperature sensor.
- Malfunction of the A/C-ECU.

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Using scan tool MB991958, check data list.

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. Start the engine.
3. Set scan tool MB991958 to the data reading mode. Item 11: Interior temperature sensor.
- Check that the interior temperature matches the displayed value on the scan tool.

NOTE: When this DTC is set and the system is in fail-safe status, the value of service data displays 25 degrees C (77 degrees F).

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

Q: Does the interior temperature match the displayed value on the scan tool?

YES: Replace the A/C-ECU. Then go to Step 5.

NO: Go to Step 2.







STEP 2. Check A/C-ECU connector C-25 and interior temperature sensor connector C-126 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are A/C-ECU connectors C-25 and interior temperature sensor connector C-126 in good condition?

YES: Go to Step 3.

NO: Repair or replace the connector. Then go to Step 5.







STEP 3. Check the wiring harness between A/C-ECU connector C-25 (terminals 1 and 20) and interior temperature sensor connector C-126 (terminals 2 and 1).

Q: Are the wiring harnesses between A/C-ECU connector C-25 (terminals 1and 20) and interior temperature sensor connector C-126 (terminals 2 and 1) in good condition?

YES: Go to Step 4.

NO: Repair the wiring harness. Then go to Step 5.

STEP 4. Check the interior temperature sensor.




1. Disconnect interior temperature sensor connector C-126.




2. When the resistance between the sensor terminals is measured under two or more temperature conditions, the resistance should approximately satisfy the illustrated values.

NOTE: The temperature conditions when checking should not exceed the range shown in the diagram.

Q: Is the interior temperature sensor in good condition?

YES: Replace the A/C-ECU. Then go to Step 5.

NO: Replace the interior temperature sensor. Then go to Step 5.

STEP 5. Recheck for diagnostic trouble code.

Check again if the DTC is set.




1. Connect scan tool MB991958 to the data link connector
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result satisfactory?

YES: The procedure is complete.

NO: Return to Step 1.