2010 Mercedes Benz C 300 (204.054) V6-3.0L (272.947) Page 646

- Secondary air injection

- M33 (electric air pump)

- Y32 (Air pump switchover valve)

Affected functions:

- Engine diagnosis

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Test 1: Test secondary air injection (function chain).

Test 2: Check component M33 (electric air pump).

Test 3: Check component Y32 (Air pump switchover valve).

1. Test secondary air injection (function chain).

Test sequence

- Switch on ignition.

- Test secondary air injection (function chain).(Move on to actuation with button F2)

Warning!Communication with ECU required.

2. Check component M33 (electric air pump).

Test 2.1: Check component M33 (electric air pump) by means of actuation.

Test 2.2: Check power supply of component M33 (electric air pump).

Test 2.3: Check component N10/1kR (Air pump or oil cooler fan relay).

2.1. Check component M33 (electric air pump) by means of actuation.

Test prerequisite

- Switch on ignition.

- Actuate component M33 (electric air pump).(Move on to actuation with button F2)

Warning!Communication with ECU required.

2.2. Check power supply of component M33 (electric air pump).

Test prerequisite

- Actuation is not OK.

Test sequence

- Switch off ignition.

- (M33) Measure direct voltage with multimeter between 2 and 1 (M33)

- Switch on ignition.

- Proceed to 'Actuation' with F2

Specified value

- Voltage[11.0...15.0] V