Air Injection Pump Relay: Testing and Inspection

Secondary Air Injection Pump Relay, Checking

Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.

Test requirements
- FuseS131 OK.
- Fuse S234 OK.
- Fuel Pump (FP) Relay J17 OK.
- Battery voltage at least 12.5 V.
- All electrical consumers switched off (radiator fan must NOT run during test).
- A/C switched off.
- The ignition switched off.

Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis

Start diagnosis
- Remove the Secondary Air Injection (AIR) Pump Relay J299.

Checking voltage
- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay J299 socket 1/30 to Ground (GND).

Specified value: battery voltage.

If the specified value was not obtained:
- Check the Secondary Air Injection (AIR) Pump Relay J299 socket 1/30 to Battery A (+) for an open circuit or a short circuit.
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If the specified value was obtained:
- Switch the ignition on.
- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay J299 socket 3/85 to Ground (GND) for voltage.

Specified value: battery voltage.

- Switch the ignition off.

If the specified value was not obtained:
- Check the Secondary Air Injection (AIR) Pump Relay J299 socket 4/86 to the Fuel Pump (FP) Relay J17 socket 19/86 for an open circuit or a short circuit.
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.
- Install the test box VAG1598/31.

If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J220.
- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay J299 socket 3/85 to the Motronic Engine Control Module (ECM) J220 electrical harness connector terminal 46 for resistance.

Secondary Air Injection (AIR) Motronic Engine Control Module (ECM) J220
Pump Relay J299 socket electrical connector terminal
terminal or test box socket
3/85 46

Specified value: 1.5 Ohms Max.

If the specification was not obtained:
- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and voltage supply was OK:
- Replace the Secondary Air Injection (AIR) Pump Relay J299.
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.

If the DTC does not return:
Repair complete, Generate readiness code. Readiness Code
- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Motronic Engine Control Module (ECM) J220.
- Assembly is performed in the reverse of the removal.

Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code.

End of diagnosis.