012

Symptom: Parking heater fails to start.

012

Fault symptom

Parking heater fails to start.

Condition

The temperature of coolant temperature sensor 1 or coolant temperature sensor 2 is higher than 125°C.

Parking heater activated.

Diagnostic help

Diagnostic trouble code 017, 041 or 042 may also have been generated.

Parking heater can be activated with Tech 2.

Parking heater function can be programmed in SID.

Eberspächer diagnostics instrument used for diagnosis.

Diagnostic procedure

1. Check coolant level

•	Check that the coolant level in the cooling system is between min. and max.

Test results OK?

YES

-	Go to point 3.

NO

-	Go to point 2.

2. Check for leakage

•	Top up with coolant to the recommended level.

•	Check that there is no leakage.

Test results OK?

YES

-	Bleed the system.

-	Go to point 8.

NO

-	Rectify the leak.

-	Top up with coolant to the recommended level.

-	Go to point 8.

3. Check coolant hoses

•	Check that there are no kinks in the coolant hoses.

Test results OK?

YES

-	Go to point 4.

NO

-	Eliminate any kinks in the coolant hoses.

-	Go to point 8.

4. Check intake and exhaust hoses.

•	Check that the intake and exhaust hoses are not clogged.

Test results OK?

YES

-	Go to point 5.

NO

-	Repair or replace the hose or hoses concerned.

-	Go to point 8.

5. Check water circulation

•	Contact: SID.

•	Activate parking heater (ON).

•	Check that the water pump starts.

Test results OK?

YES

-	Go to point 7.

NO

-	Go to point 6.

6. Check the water pump

•	Unplug the water pump connector.

•	Connect test lamp 86 11 857 to the female connector pins.

•	Contact: SID.

•	Activate parking heater (ON).

•	The lamp should come on.

Test results OK?

YES

-	Change the water pump.

-	Go to point 8.

NO

-	Check that there is no open circuit in the leads between the water pump and control module.

-	Go to point 8.

7. Check the non-return valve

•	Check operation of non-return valve.

Test results OK?

YES

-	Go to point 8.

NO

-	Change the non-return valve.

-	Go to point 8.

8. Final check

•	Delete DTCs in all systems.

•	Contact: SID.

•	Activate parking heater (ON).

•	Perform a functionality check.

•	Evaluate the functionality check.

•	Check that the diagnostic trouble code has not recurred.

Test results OK?

YES

-	Fault rectified successfully.

NO

-	See ’Procedure for replacement of control module’.