Circuit/System Testing

Inspect the secondary air injection system for the following conditions:
- Hoses/pipes for a restriction or blockage
- Hoses/pipes for being disconnected
- Plugged secondary air injection pressure sensor port
- Damaged secondary air injection check valve
If a condition is found, repair as necessary.
If a condition is not located and the secondary air injection pump operates with no pressure change, replace the G21 secondary air injection pump.
Ignition OFF, remove the KR25 secondary air injection pump relay.
Ignition ON, verify that a test lamp does not illuminate between the controlled output circuit terminal 30 and ground.
If the test lamp illuminates, test the controlled output circuit for a short to voltage.
Verify that a test lamp illuminates between the secondary air injection pump relay switch B+ circuit terminal 87 and ground.
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay coil ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
Connect a 20 A fused jumper wire between the secondary air injection pump relay switch B+ circuit terminal 87 and the controlled output circuit terminal 30. The G21 secondary air injection pump should turn ON.
If the secondary air injection pump does not activate, test the controlled output circuit and the secondary air injection pump ground circuit for an open/high resistance. If the circuits test normal, test or replace the G21 secondary air injection pump.
If all circuits test normal, replace the KR25 secondary air injection pump relay.