Auto. Trans.
- Disconnect air suction lower hose from anti-afterburn valve. Start engine and quickly raise engine speed to 3500 RPM and close throttle suddenly. Check for vacuum at air suction lower hose. There should be vacuum.
- If there is vacuum, proceed to step 4). If there is no vacuum, check for voltage at anti-afterburn control solenoid valve Yellow/Black wire. If there is no voltage present, check for voltage at control unit connector (Black/Yellow wire). If there is no voltage, check wiring.
- Check Brown/Black wire for continuity between control unit and ground. There should be continuity. Check wiring and fuse between control unit connector (Blue/White wire) terminal and ignition switch start terminal.
- If voltage is present, disconnect vacuum hose No. 31 from anti-afterburn valve. Check for vacuum. If there is no vacuum present, disconnect vacuum hose No. 30 from anti-afterburn valve and check for vacuum. If there is no vacuum, check for leaks or blockage and retest.
- If vacuum is present, replace anti-afterburn valve and retest. Stop engine. Connect voltmeter to anti-afterburn control solenoid valve. Turn ignition switch to "START" position and release key while checking voltage.
- There should be no voltage for 4 seconds after releasing key. Voltage should return after 4 seconds. If voltmeter does not indicate as described, check for voltage at control unit connector (Black/Yellow wire). If there is no voltage, check wiring.
- Check Brown/Black wire for continuity between control unit and ground. There should be continuity. Check wiring and fuse between control unit connector (Blue/White wire) terminal and ignition switch start terminal.