After-Run Coolant Pump: Testing and Inspection

LEGEND
1 Thermostat Housing
2 Bolt
3 Thermostat
4 Connection
5 Bolt
6 O-ring
7 Connection
8 Plug
Or
8 A/C Cut-Out Thermal Switch And Third Speed Fan Control Thermal Switch
9 After-Run Coolant Fan Control Thermal Switch With Engine Coolant Temperature Sensor.
10 Engine Coolant Temperature Sensor
11 Retaining Clip

NOTE: During testing procedures, refer to the component location illustration above and component notes below.

COMPONENT NOTES
Bolt (2)
- Tighten to: 10 Nm (7 ft. lbs.).

Thermostat (3)
- Checking, submerge thermostat in heated water and observe as follows:
- Opening begins at approx: 80°C (176°F).
- Opening ends at approx: 105°C (221°F).
- Opening stroke, minimum: 7 mm (0.2800 inches)

Bolt (5)
- Tighten to: 10 Nm (7 ft. lbs.).

O-ring (6)
- Always replace.

Plug (8)
- For models without A/C.

OR

A/C Cut-Out Thermal Switch And Third Speed Fan Control Thermal Switch (8)
- For models with A/C.
- Color: brown.
- Four pin connector.

After-Run Coolant Fan Control Thermal Switch With Engine Coolant Temperature Sensor (9)
- Color: yellow.
- Four pin connector.
- Switching Temperatures:
- On: 101-107°C (214-225°F).
- Off: 94-100°C (210-212°F).

Engine Coolant Temperature Sensor (10)
- Color: blue.
- For Motronic.
- Refer to Powertrain Management.

Retaining Clip (11)
- Ensure clip is seated securely.

PROCEDURE
1. Remove cover above thermostat housing.
2. Switch on ignition and then switch off again.
3. Disconnect the four pin harness connector from After-Run Coolant Fan Control Thermal switch with Engine Coolant Temperature sensor -yellow-.





4. Bridge terminals -1- and -3- of connector (brown/red and brown wires) with jumper wires from adaptor kit tool No. VW 1594, or equivalent.
5. Coolant fan and after-run coolant pump must run.

NOTE: Check coolant fan after-run using WAG 1466 tester, refer to wiring diagrams.