Secondary Air Injection Pump Relay, Checking
Secondary Air Injection Pump Relay, Checking
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Test requirements
• The Secondary Air Injection (AIR) Pump Relay (-J299-) fuses OK.
• The Motronic Engine Control Module (ECM) Power Supply Relay (J271) fuse 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. Refer to => [ General Diagnosis ] 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 3/27 to Ground (GND).
Specified value: battery voltage.
If the specified value was not obtained:
- Check the wiring connections from the Battery to the Secondary Air Injection (AIR) Pump Relay (-J299-) socket 3/27 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:
- Switch the ignition on.
- Using a Multimeter, check the Motronic Engine Control Module (ECM) Power Supply Relay (J271) socket 2/87 to the Secondary Air Injection (AIR) Pump Relay (-J299-) socket 1/25 for voltage.
Specified value: battery voltage.
- Switch the ignition off.
If the specified value was not obtained:
- Check the wiring connections from the Motronic Engine Control Module (ECM) Power Supply Relay (J271) socket 2/87 to the Secondary Air Injection (AIR) Pump Relay (-J299-) socket 1/25 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 activation
- Install the Secondary Air Injection (AIR) Pump Relay (-J299-).
- Switch the ignition on.
- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay (-J299-) socket 2/24 to Ground (GND)
- Switch the ignition off.
Specified value: battery voltage.
If the specified value was not obtained:
- Check or replace the Secondary Air Injection (AIR) Pump Relay (-J299-).
- 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. Refer to repair information (test box) at Engine Control Module.
If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) (J220). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.
- Using a Multimeter, check the Secondary Air Injection (AIR) Pump Relay (-J299-) socket 2/24 to the Motronic Engine Control Module (ECM) (J220) electrical harness connector T121 terminal 46 for resistance.
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-). Refer to repair information.
If no malfunction is found in the wiring and voltage supply was not OK:
- Replace the Motronic Engine Control Module (ECM) (J220). Refer to => [ Motronic Engine Control Module, Replacing ] Motronic Engine Control Module, Replacing.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.
- End of diagnosis.