Malfunction of Secondary Air Injection

Malfunction Of Secondary Air Injection

Test 1 Test Secondary Air Injection (Function Chain). (Only (USA), EURO 3, EURO 4, D4)
Test 2 Check Component M33 (Electric Air Pump). (Only (USA), EURO 3, EURO 4, D4)
Test 3 Check Component Y32 (Air Pump Switchover Valve). (Only (USA), EURO 3, EURO 4, D4)


1 Test Secondary Air Injection (Function Chain). (Only (USA), EURO 3, EURO 4, D4)
Test sequence
- Ignition ON
- Test secondary air injection (function chain). (Actuate with key F2.)

Note: Component M4/3 (engine/AC electric suction fan) runs with an on/off ratio of 50 % during the actuations for safety reasons.

Note! Communication with ECU required.

** End of Test **


2 Check Component M33 (Electric Air Pump). (Only (USA), EURO 3, EURO 4, D4)


Test 2-1 Test Actuation of Component M33 (Electric Air Pump).
Test 2-2 Test Voltage Supply of Component M33 (Electric Air Pump).
Test 2-3 Check Component N10/1kR (Air Pump Relay).



2-1 Test Actuation of Component M33 (Electric Air Pump).

Test requirement
- Engine at idle speed
- Actuate component M33 (electric air pump).(Actuate with key F2.)

Note! Communication with ECU required.

** End of Test **


2-2 Test Voltage Supply of Component M33 (Electric Air Pump).





Figure legend
- G003 Multimeter
- M33 (electric air pump)

Test requirement
- Actuation is not okay.

Test sequence
- Switch off ignition.
- (M33) 2 <--> 1 (M33)
- Switch on ignition.
- Actuate with key F2.

Specified value
- Voltage[11.0...14.5] V

Note! Communication with ECU required.

** End of Test **


2-3 Check Component N10/1kR (Air Pump Relay).

2-3-1 Test Current Consumption Of Component N10/1kR (Air Pump Relay).

Test sequence
- Switch off ignition.
- Connect socket box (35-pin) to component N3/10 (ME-SFI control module).
- Connect socket box (126-pin) to component N3/10 (ME-SFI control module).
- (5.5) Pin 5 of 35 <--> Pin 123 of 126 (4.38)
- 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 measured value okay?
Yes
The measured value is o.k. ** End of test **
No
The measured value is not o.k.
Possible cause and remedy
- Leads to component N10/1kR (Air pump relay)
- N10/1kR (Air pump relay)

** End of test **


3 Check Component Y32 (Air Pump Switchover Valve). (Only (USA), EURO 3, EURO 4, D4)

Test 3-1 Test Actuation Of Component Y32 (Air Pump Switchover Valve).
Test 3-2 Test Current Consumption Of Component Y32 (Air Pump Switchover Valve).

3-1 Test Actuation Of Component Y32 (Air Pump Switchover Valve).

Test sequence
- Ignition ON
- Actuate component Y32 (Air pump switchover valve).(Actuate with key F2.)

Note! Communication with ECU required.

** End of Test **


3-2 Test Current Consumption Of Component Y32 (Air Pump Switchover Valve).

Test requirement
- Actuation is not okay.

Test sequence
- Switch off ignition.
- Connect socket box ( 35-pin) to component N3/10 (ME-SFI control module).
- Connect socket box ( 126-pin) to component N3/10 (ME-SFI control module).
- (5.7) 7 22 (2.13)
- Switch on ignition.

Specified value
- Amperage[0.3...0.5] A

Question
- Is the measured value okay?
Yes
The measured value is o.k. ** End of test **
No
The measured value is not o.k.
Possible cause and remedy
- Voltage supply of component Y32 (Air pump switchover valve) (Wiring diagrams)
- Leads to component Y32 (Air pump switchover valve)
- Y32 (Air pump switchover valve)

** End of test **