Heater Core Temperature Sensor / Switch: Service and Repair

Digital Climate Control (Climatronic)

Rear Heater, from 09.98 Servicing


CAUTION! Before beginning repairs on the electrical system:

- Obtain the anti-theft radio security code.
- Switch the ignition off
- Disconnect the battery Ground (END) strap.
- After reconnecting battery, re-code and check operation of anti-theft radio. Also check operation of clock and power windows according to Repair Manual and/or Owner's Manual.






1 - Vent, for rear passenger zone
2 - Cover plate
3 - Gasket
4 - Air distribution housing
5 - Rear Warm Air Fan -V47-
6 - Coolant Pipe
7 - Auxiliary Heater Valve -N172-
8 - Coolant hose
9 - Sliding door footwell insert
10 - Air intake duct
11 - Hose clamp
12 - Coolant hose, return
13 - Coolant hose, supply
14 - Heater core
- GInstall seals around entire circumference of heater core

NOTE: Always change coolant after Repairs.

15 - Rear Heater Core Temperature Sensor -G154-
- Inserted into heater core
- If sensor -G56- malfunctions, default value of 42 °C (108 °F) is assumed
- Removing
- Remove rear heater core first
16 - Control Module for Warm Air Blower -J350- (rear)
- Function: Controls blower speed of rear warm air fan -V47- with variable ground signal