P0128

Component Y110 (Three-disk thermostat valve) jams in opened position. : Coolant temperature rises too slowly. (P0128)


Possible cause:

- Mechanical fault of component Y110 (Three-disk thermostat valve)
Affected functions:

- Engine diagnosis

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Test 1: Check component Y110 (Three-disk thermostat valve).

1. Check component Y110 (Three-disk thermostat valve).

Test 1.1: Component Y110 (Three-disk thermostat valve) is mechanically damaged or it sticks.

Test 1.2: Test current consumption of component Y110 (Three-disk thermostat valve).

1.1. Component Y110 (Three-disk thermostat valve) is mechanically damaged or it sticks.

Test 1.1.1: Y110 (Three-disk thermostat valve) : Coolant temperature is not reached.

Test 1.1.2: Y110 (Three-disk thermostat valve) : Coolant temperature is too high.

1.1.1. Y110 (Three-disk thermostat valve) : Coolant temperature is not reached.
Warning!Communication with ECU required.


1.1.2. Y110 (Three-disk thermostat valve) : Coolant temperature is too high.
Warning!Communication with ECU required.


1.2. Test current consumption of component Y110 (Three-disk thermostat valve).
Figure legend

- A -ConnectionTest cable 35-pin socket box
- 001 -Sockets of component N3/10 (ME-SFI [ME] control unit)
- 05 -35-pin socket box
- 050 -126-pin socket box
- 108 -Test cable 266 589 01 63 00
- N3/10 (ME-SFI [ME] control unit)
- II 1-63ConnectionTest cable
- III 64-126ConnectionTest cable
Warning!

- Connection A of test cable 108 may NOT be connected to connection B of the 126-pin socket box (050).
Continue to test with button F2







Test sequence

- Measure direct current with multimeter between sockets [F.4] 100 and [M.54] 54 of the 126-pole socket box tester.
- Switch on ignition.
Specified value

- Amperage[0.6...1.2] A
Question

- Is the measurement value OK?


YES
The measurement value is OK.End of test

NO
The measurement value is not OK.Possible cause and remedy

- N10/1f57 (Fuse 57)
- N10/1kR (Circuit 87 relay, engine)
- Check lines from component N3/10 (ME-SFI [ME] control unit) to component Y110 (Three-disk thermostat valve).
- Y110 (Three-disk thermostat valve)
End of test