Diagnostic Circuit Check: Notes

1. If engine runs, proceed to step 4). If engine will not start, check power supply to ECM. Check for battery voltage at ECM pins B1 and C16 (Red/Yellow wires). Power should be present with ignition on or off. See the WIRING DIAGRAMS article in this section. If battery volatge does not exist, check "ECM" slow blow fuse on left shock tower and wiring to ECM.
2. Check 10A fuse (No. 13) in fuse box (left side of dash). This fuse powers main relay. If fuse is okay, check the main relay, relay ground, and relay wiring to ECM. See I - EFI SYS/COMP TESTS to test main relay. Main relay is activated by Orange wire through the ignition switch.
3. If power supply to ECM is okay, check for bad ECM ground or ECM.
4. If engine runs, ensure ignition is off. Unplug ECM 24-pin connector. Turn ignition on. Backprobe terminal A5 (Violet wire) with test light. If test light is "ON", ECM or ECM ground is faulty. If test light is "OFF", check 10 amp fuse (No. 11) in fuse box. If fuse is okay, check Violet wire from ECM to "CHECK ENGINE" light in dash. Ensure "CHECK ENGINE" light bulb is good.