Control Module HVAC: Diagrams
Climatronic Control Module -J255-, Multi-pin Connector Assignments
28-pin multi-connector -A- (-T28a/-)
1 - Terminal 15
4 - Heater control module -J162- (where applicable)
5 - Terminal 30
7 - Water pump
8 - Vehicle speed signal from instrument cluster
9 - Data Link Connector (DLC) K wire
10 - A/C Pressure Switch -F129-
11 - First Speed Engine Coolant (EC) Fan Control (FC) Relay (V7, V35) -J279- (or Coolant Fan Control (FC) Relay -J26- where applicable) and to Coolant Fan Control (FC) Thermal Switch -F18-
12 - Relay for Climatronic -J254-
13 - Motronic Engine Control Module (ECM) -J220- (idle speed control)
14 - First Speed Engine Coolant (EC) Fan Control (FC) Relay (V7, V35) -J279- (or Coolant Fan Control (FC) Relay -J26- where applicable) and to Coolant Fan Control (FC) Thermal Switch -F18-
15 - Terminal 31 (Ground)
17 - Front Vent Temperature Sensor -G152- (Ground signal)
18 - A/C Pressure Switch -F129- pin 3 (diagnosis 16 bar)
19 - A/C Pressure Switch -F129- pin 1 (diagnosis 2/32 bar)
20 - X contact
21 - Motronic Engine Control Module (ECM) -J220-
22 - After-Run Coolant Pump -V51- and to After-Run Coolant Thermal Switch -F95-
23 - A/C Engine Coolant Temperature (ECT) Sensor -G110-
24 - Terminal 58b
27 - Outside Air Temperature Sensor -G17-
28-pin multi-connector -B- (-T28b/-)
1 - Vacuum Valve Rail -N53- (center vent)
2 - Vacuum Valve Rail -N53- (recirculation)
3 - Temperature Regulator Flap Motor -V68-, (cold above)
4 - Footwell/defroster flap motor - V85- (footwell)
5 - Footwell/defroster flap motor - V85- (defroster, top)
6 - Central Air Flap motor - V70- (lower center vent)
7 - Central Air Flap motor - V70- (footwell)
8 - Temperature Regulator Flap Motor -V68-, (warm below)
11 - Control module for fresh air blower -J126-
12 - Relay for Climatronic -J254- and Fresh Air Blower -V2- (+)
13 - Relay for Climatronic -J254- and Fresh Air Blower -V2- (-)
14 - Reference voltage 5V (for flap position sensors, flap motors and Sunlight Photosensor -G107-)
15 - Front Vent Temperature Sensor -G152-
16 - Footwell/Defrost Flap Motor Position Sensor -G114- (5V = cold; 0V warm)
17 - Central Flap Motor Position Sensor -G112- (5V = cold; 0V warm)
18 - Temperature Regulator Flap Motor Position Sensor -G92- (5V = cold; 0V warm)
19 - Sunlight Photosensor -G107-
20 - Ground signal (for Central Air Flap Motor - V70-; for Footwell/defroster Flap Motor - V85-; for Temperature Regulator Flap Motor Position Sensor -G92-
28-pin multi-connector -C- (-T28c/-)
1 - A/C Refrigerant Shut-Off Valve -N43-
3 - Control module with indicator unit in instrument panel insert -J285-
4 - Control Module for Warm Air Blower -J350-
6 - Fan Relay -J323- and Rear Warm Air Fan -V47- (+)
7 - Control Module for Warm Air Blower -J350- and Rear Warm Air Fan -V47- (-)
8 - Rear A/C Control Head (Climatronic) -E265-
10 - Control Module for Blower for Evaporator -J349- and Rear Evaporator Fan -V20- (-)
11 - Fan Relay -J323-
12 - Control Module for Blower for Evaporator -J349-
14 - Rear A/C Control Head (Climatronic) -E265- (Data bus)
15 - Auxiliary Heater Valve -N172-
18 - Rear Evaporator Temperature Sensor -G153-
19 - Rear Heater Core Temperature Sensor -G154-
20 - Ground signal (for Rear Evaporator Temperature Sensor -G153- and Rear Heater Core Temperature Sensor -G154-)