Manufacturer Code Charts: 2023

Relay for air pump (P2257, P2258)


Possible cause:

- N10/1kA (Air pump relay)
Affected functions:

- Engine diagnosis

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Test 1: Check component N10/1kA (Air pump relay).

Test 2: Check component N10/9kO (Charge air cooler recirculation pump relay) by means of actuation.

1. Check component N10/1kA (Air pump relay).
Test prerequisites

- Fuse K40/4f32 (Fuse 32) is OK.
- Actuation of component M33 (electric air pump) is not OK.
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 (3.4) 37 and (4.21) 106 of the 126-pole socket box tester.
- Switch on ignition.
Warning!Perform the measurement only for a short time so that component M33 (electric air pump) does not overheat.Specified value

- Amperage[0.1...0.3] A
- Component M33 (electric air pump) is switched on and is heard to run.
Question

- Is the measurement value OK?







YES
The measurement value is OK.Question

- Does component M33 (electric air pump) run during the current measurement?







YES
The test was okay.End of test

NO
Test actuation of component M33 (electric air pump).
Test sequence

- Switch off ignition.
- Detach coupling at component M33 (electric air pump).
- (M33) Measure direct voltage with multimeter between 2 and 1 (M33)
- Switch on ignition.
- Insert bridge for actuating component K40/4kO (Air pump or reserve relay).:
- Use fuse cable for bridge.
- Bridge between sockets (3.4) 37 and (4.21) 106 of the 126-pole socket box tester.
Specified value

- Voltage[11.0...14.5] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further possible causes of fault

- M33 (electric air pump)
End of test

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

- Voltage supply of component K40/4kO (Air pump or reserve relay)
- K40/4kO (Air pump or reserve relay)
- Lines to component M33 (electric air pump)
- M33 (electric air pump)
End of test







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

- Lines to component K40/4kO (Air pump or reserve relay)
- K40/4kO (Air pump or reserve relay)
End of test







2. Check component N10/9kO (Charge air cooler recirculation pump relay) by means of actuation.
Test prerequisite

- The power supply of component N10/9 (SAM control module with fuse and relay module, front passenger) is OK.
- Fault code 9143 is present, or a relevant actual value is not OK.
Status of the relevant fault codes:Test sequence

- Carry out actuation of component N10/9kO (Charge air cooler recirculation pump relay).
- Call up 'Actuation' with key F2 .







Warning!Communication with ECU required.