Ignition Output Signal
- Turn ignition off. Disconnect alternator sense fuse in under-hood relay box for 10 seconds to reset ECU. Start engine and observe "CHECK ENGINE" light. If light is off, problem is intermittent. Test drive and check again.
- If light is on, turn ignition off. Disconnect 4-wire connector on ignitor unit. Turn ignition on. Measure voltage between Black/Yellow (pos.) wire terminal and ground.
- If battery voltage exists, proceed to step 4). If battery voltage does not exist, repair open in Black/Yellow wire between the ignitor unit and ignition switch.
- Turn ignition off. Connect ECU test harness between ECU and ECU connector. Reconnect 4-wire ignitor connector. Turn ignition on. Individually, measure voltage between ECU terminals B15 (pos.), B16 (neg.), and A18 (ground). See Figure . If battery voltage is present in any of these terminals, go to step 5). If battery voltage does not exist, go to step 6).
- If battery voltage exists, substitute a known good ECU and recheck. If condition is rectified, replace original ECU.
- If battery voltage does not exist, turn ignition off. Disconnect 4-wire connector from ignitor unit, and ECU connector "B". Check continuity of Red/Blue wire between ECU and ignitor unit.
- If no continuity exists, repair open in Red/Blue wire. If continuity exists, check continuity to body ground and Red/Blue wire on ignitor unit 4-wire connector.
- If no continuity exists, replace ignitor unit. If continuity exists, repair short in Red/Blue wire and/or replace ignitor unit.