0155

R48 (Two-disk thermostat heating element) : Open circuit (P0597)


Possible cause:

- Z7/36 (Circuit 87 M2e connector sleeve)
- R48 (Two-disk thermostat heating element)
- K40/4f44 (Fuse 44)
- K40/4kK (Engine electronics and chassis relay)
Affected functions:

- Heating
- Engine cooling

-------------------------------------------------

Test 1: Arrangement of fuses

Test 2: Check component R48 (Two-disk thermostat heating element).

Test 3: Power supply

1. Arrangement of fuses
End of test

2. Check component R48 (Two-disk thermostat heating element).

Test 2.1: Component R48 (Two-disk thermostat heating element) is mechanically damaged or it sticks.

Test 2.2: Test current consumption of component R48 (Two-disk thermostat heating element).

2.1. Component R48 (Two-disk thermostat heating element) is mechanically damaged or it sticks.

Test 2.1.1: R48 (Two-disk thermostat heating element) : Coolant temperature is not reached.

Test 2.1.2: R48 (Two-disk thermostat heating element) : Coolant temperature is too high.

2.1.1. R48 (Two-disk thermostat heating element) : Coolant temperature is not reached.
Warning!Communication with ECU required.


2.1.2. R48 (Two-disk thermostat heating element) : Coolant temperature is too high.
Warning!Communication with ECU required.


2.2. Test current consumption of component R48 (Two-disk thermostat heating element).
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).







Test sequence

- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI [ME] control unit).
- 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

- K40/4f44 (Fuse 44)
- K40/4kM (Circuit 30z relay)
- Check lines from component N3/10 (ME-SFI [ME] control unit) to component R48 (Two-disk thermostat heating element).
- R48 (Two-disk thermostat heating element)
End of test







3. Power supply
Voltage supply via component Z7/36 (Circuit 87 M2e connector sleeve)
Possible cause and remedy

- Check voltage supply according to wiring diagram.