Circuit/System Testing

Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve. Ignition ON,
Verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 Ω in the ignition circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF, remove the test lamp.
2. Test for infinite resistance between the ignition circuit and ground
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, test all components connected to the ignition voltage circuit for a short and replace as necessary.
- Go to next step: If the test lamp illuminates
Verify that a test lamp does not illuminate between the ignition circuit terminal 1 and the control circuit terminal 2.
- If the test lamp illuminates
1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the control circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the K20 Engine Control Module.
- Go to next step: If the test lamp does not illuminate
Ignition OFF, all systems Off. Reconnect all harness connectors. Ignition ON, engine running.
With a scan tool, increase and decrease the EVAP Canister Purge Solenoid Valve duty cycle.
- If engine speed does not vary according to valve opening.
- Test or replace the EVAP Canister Purge Solenoid Valve.
- If the engine speed varies according to valve opening.
Replace the K 20 Engine Control Module.