1999 Mercedes Benz Truck ML 430 Diagnostic Trouble Code (DTC)

Secondary Air Injection : Malfunction (Functional Chain)
Test 1 Test secondary air injection (function chain). (only (USA), EURO 3)
Test 2 Check component M33 (electric air pump). (only (USA), EURO 3)
Test 3 Check component Y32 (Air pump switchover valve). (only (USA), EURO 3)
1 Test secondary air injection (function chain). (only (USA), EURO 3)
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.
2 Check component M33 (electric air pump). (only (USA), EURO 3)
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 K40/7kN (Air pump relay)
2-1 Test actuation of component M33 (electric air pump)

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