Secondary Air Injection Pump Relay, Checking

Secondary Air Injection Pump Relay, Checking

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

Test requirements
- Fuse Strip S88 OK.
- Fuse S130 OK.
- The Engine Component Power Supply Relay J757 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 2/30 to Ground (GND).

Specified value: battery voltage.

If the specified value was not obtained:
- Check the wiring connection from the battery to the Secondary Air Injection (AIR) Pump Relay -J299- socket 2/30 for an open circuit or a short circuit.
- Check the wiring connections for damage, corrosion, lose or broken terminals.
- If necessary, repair the faulty wiring connection.

If the specified value was obtained:
- Crank the engine.
- Using a Multimeter , check the Secondary Air Injection (AIR) Pump Relay -J299- socket 6/86 to Ground (GND).

Specified value: battery voltage.

- Switch the ignition off.

If the specified value was not obtained:
- Check the wiring connection from the Engine Component Power Supply Relay J757 socket 2/87 to the Secondary Air Injection (AIR) Pump Relay -J299- socket 6/86 for an open circuit or a short circuit.
- Check the wiring connections for damage, corrosion, lose 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.

If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J623.
- Using a Multimeter , check the Secondary Air Injection (AIR) Pump Relay -J299- socket 4/T to the Motronic Engine Control Module (ECM) J623 electrical harness connector T94 terminal 49 for resistance.

Secondary Air Injection Motronic Engine Control Module
(AIR) Pump Relay -J299- (ECM) J623 electrical connector
socket terminal T94 terminal or test box socket
4/T 49

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, lose 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-.

If no malfunction is found in the wiring and voltage supply was not OK:
- Replace the Motronic Engine Control Module (ECM) J623.

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. Monitors, Trips, Drive Cycles and Readiness Codes

- End of diagnosis.