Coolant Fan Control (FC) Module -J293-

Coolant Fan Control (FC) Module -J293-, Electrical Testing

Special tools, testers and auxiliary items
- Multimeter (Fluke 83 or equivalent)
- VW 1594 connector test kit
- VAG 1527B voltage tester (or equivalent diode type tester)
- VAS 5051 Vehicle Diagnostic Testing and Information System for testing square wave (pressure) signal on vehicles with high pressure sensor -G65-.

Test conditions
- All fuses OK according to wiring diagram
- DTC memory of A/C Control Head -E87- checked - no DTCs stored.
- No compressor shut-off conditions displayed in read measuring value block (Display Group 01, display field 1) for A/C Control Head -E87- while engine is running.
- A/C Control Head -E87- installed.
- Connectors A and B detached from -J293-.

Coolant Fan Control (FC) Module -J293- (vehicles with A/C pressure switch -F129-), electrical testing

Terminal assignments at -J293- (vehicles with -F129-)

Location: In engine compartment on left long member.

Function:
- Activates coolant fan(s) -V7- (speeds 1 and 2)
- Activates A/C clutch -N25-.

NOTE: The function of -J293 and vehicle wiring layout will vary depending on whether vehicle is equipped with A/C pressure switch -F129 or high pressure sensor -G65-.

Terminal assignments and switching conditions (A/C pressure switch -F129-)

- Switch between terminals -1- and -2- opens if there is excess pressure or insufficient refrigerant system pressure (A/C clutch -N25- is disengaged).
- Switch between terminals -3- and -4- closes when refrigerant system pressure rises (coolant fan(s) -V7- switched to speed 2).

Switching conditions - Coolant Fan Control (FC) Thermoswitch -F18/-F54
- F54 between terminals 1 and 2: Closes at approx. 95 degree C (-V7- switched to speed 1).
- F18 between terminals 3 and 2: Closes at approx. 102 degree C (-V7- switched to speed 2).

Switching conditions - Engine Coolant Temperature (ECT) Waring Switch -F14-
- Switch opens at approx. 118 degree C - compressor is switched off.

NOTE: -F14- is only installed on vehicles with A/C pressure switch -F129-.

Test step 1 - Voltage supply, Ground (GND) supply

Test Step 1.1 - 1.4:

Test step 2 - Activation of coolant fan(s) -V7-

Test Step 2.1 - 2.2:

Test Step 2.3 - 2.4:

Test Step 2.5 - 2.6:

Test step 3 - Activation of A/C clutch -N25-

Test Step 3.1:

Test Step 3.2:

Coolant Fan Control (FC) Module -J293- (vehicles with high pressure sensor -G65-), electrical testing

Terminal assignments at -J293- (vehicles with -G65-)

Location: In engine compartment on left long member

Function:
- Activates coolant fan (s) -V7 (speeds 1 and 2)
- Activates A/C clutch -N25
- Processes the square-wave signal from high pressure sensor -G65- and sends a positive signal to -E87- to indicate the refrigerant system pressure is OK.
- Switches on after-run coolant pump -V51 (if equipped) for continued coolant circulation when the ignition is switched on. The pump continues to operate for a short time after the ignition has been switched off.

NOTE: The following -J293- connector A terminals are vacant:
Terminal 1 (on vehicles without after-run coolant pump -V51-)
Terminals 3, 5, 11 and 14

- -J293- connector A,, terminal 13 is intended for disengaging -A/C clutch -N25- when the instrument cluster sends "excessive coolant temperature" signal. As disengagement of - N25- also takes place via the A/C Control Head -E87-, -J293- terminal 13 may be vacant on some vehicles, dependant of vehicle wiring configuration.
- The function of Coolant Fan Control (FC) Module -J293 and vehicle wiring layout will vary depending on whether vehicle is equipped with A/C pressure switch -F129 or high pressure sensor -G65-.
- Various versions of Coolant Fan Control (FC) Module -J293-, used in conjunction with high pressure sensor -G65- may be installed. At the time of publishing however, All TT equipped with -J293- / -G65- have version where coolant fan(s) -V7- speed 1 is always switched on automatically whenever the A/C clutch -N25- is energized (regardless of refrigerant system pressure).

Terminal assignments and switching conditions (high pressure sensor -G65-)

Terminal -1- Ground (GND)
Terminal -2- Signal output (square-wave signal to -J293- and ECM)
Terminal -3- Positive (terminal 15)

NOTE:

- When electrical connector at -B- is disconnected, the A/C clutch -N25- cannot be activated.
- High pressure sensor -A- transmits a square-wave signal at a pulse rate that varies according to the refrigerant system pressure.

Switching conditions - Coolant Fan Control (FC) Thermoswitch -F18/- F54
- -F54- between terminals 1 and 2: Closes at approx. 95 degree C (-V7- switched to speed 1).
- -F18- between terminals 3 and 2: Closes at approx. 102 degree C (-V7- switched to speed 2).

Test step 1 - Voltage supply, Ground (GND) supply