## Evaporative Emission Control System

#### Evaporative Emission (EVAP) System Troubleshooting

11-580

With TWC model

1. Inspect the No. 4 ACG (10A) fuse in the under-dash fuse/relay box.

Is fuse OK?

YES | - Go to step 2.
NO | - Replace the fuse, and recheck.

2. Disconnect the vacuum hose (A) from the EVAP canister (B) and connect a vacuum pump/gauge (C) to the hose.

3. Start the engine and let it idle.

   NOTE: Engine coolant temperature must be below 70°C (158°F).

4. Quickly raise the engine speed to 3,000 rpm (min-1).

Is there vacuum?

YES | - Go to step 5.
NO | - Go to step 10.

5. Disconnect the EVAP canister purge valve 2P connector.
6. Quickly raise the engine speed to 3,000 rpm (min-1).

Is there vacuum?

YES | - Inspect vacuum hose routing. If OK, replace the EVAP canister purge valve.
NO | - Go to step 7.

7. Turn the ignition switch OFF.
8. Disconnect ECM/PCM connector B (24P).

9. Check for continuity between the EVAP canister purge valve 2P connector terminal No. 2 and body ground.

EVAP CANISTER PURGE VALVE 2P CONNECTOR

Wire side of female terminals

Is there continuity?

YES | - Repair short in the wire between the EVAP canister purge valve and the ECM/PCM (B21).
NO | - Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.

10. Start the engine. Hold the engine at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
11. Check for vacuum at the vacuum hose after starting the engine.
12. Quickly raise the engine speed to 3,000 rpm (min-1).

Is there vacuum?

YES | - Go to step 23.
NO | - Go to step 13.

13. Turn the ignition switch OFF.
14. Inspect the vacuum hose routing.

Is the vacuum hose OK?

YES | - Go to step 15.
NO | - Repair the vacuum hose.

15. Disconnect the EVAP canister purge valve 2P connector.
16. Turn the ignition switch ON (II).