Evaporative Emission Control System

Evaporative Emission (EVAP) System Troubleshooting (cont'd)

11-581  

  1. At the harness side, measure voltage between the EVAP canister purge valve 2P connector terminals No. 1 and No. 2.

EVAP CANISTER PURGE VALVE 2P CONNECTOR

Wire side of female terminals

Is there any voltage?

YES

- Replace the EVAP canister purge valve.

NO

- Go to step 18.


  1. At the harness side, measure voltage between the EVAP canister purge valve 2P connector terminal No. 1 and body ground.

EVAP CANISTER PURGE VALVE 2P CONNECTOR

Wire side of female terminals

Is there battery voltage?

YES

- Go to step 19.

NO

- Repair open in the wire between No. 4 ACG (10A) fuse in the under-dash fuse/relay box and the EVAP canister purge valve.


  1. Turn the ignition switch OFF.
  2. Reconnect the EVAP canister purge valve 2P connector.
  3. Turn the ignition switch ON (II).

  1. Measure voltage between ECM/PCM connector terminals B21 and body ground.

ECM/PCM CONNECTOR B (24P)

Wire side of female terminals

Is there battery voltage?

YES

- Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.

NO

- Repair open in the wire between the EVAP canister purge valve and the ECM/PCM (B21).


  1. Reconnect the vacuum hose to the EVAP canister.
  2. Remove the fuel fill cap.
  3. Disconnect the purge air hose (A) from the EVAP canister and connect a vacuum/pressure gauge 0-100 mm Hg (0-4 in. Hg) (B) to EVAP canister (C).

  1. Start the engine and raise speed to 3,000 rpm (min-1).

Does vacuum appear on gauge within 2 minutes?

YES

- When vacuum appears, evaporative emission controls are OK. Check the EVAP two way valve test (see page 11-307).

NO

- Replace the EVAP canister.