To determine if the PowertrainControl Module (PCM) has detected any fault conditions that would cause a hard start or no start condition.
Key On Engine Off (KOEO) On-Demand Self Test is a functional test of the PCM performed on demand with the key on and the engine off. This test will check that all inputs and outputs (circuits, sensors, regulators, relays and solenoids) connected to the PCM are electrically operating without fault, with the exception of the Injector Driver Module DTCs.
Connect the OBDII Scan Tool to the data link connector (DLC) under the dash. Turn off accessories. If vehicle is equipped with an auxiliary powertrain control (rpm control), it must be turned off to perform self tests.
The IDM stores both historical and hard IDM fault codes; to ensure that IDM DTC is a hard fault, you must first clear continuous DTCs (be sure to record all fault codes before clearing). After clearing, rerun self test; a fault must be present at the time of testing for the KOEO On Demand Self Test to detect the fault. If a fault is detected, a Diagnostic Trouble Code (DTC) will be the output on the data link at the end of the test when requested by a scan tool. Only a hard fault code (DTC) will be displayed. If no IDM codes reappear, then the fault is an intermittent IDM fault.
After test, cycle key to off before running other tests or driving vehicle.
If performing repeated self tests, it may be necessary to unplug glow plug relay to keep battery from going dead. Ignore DTC 0380 while glow plug relay is unplugged.
The most likely PCM detectable faults that will cause a no start or hard start condition are:
- CMP sensor inactive faults.
- IPR output circuit check fault.
- FDCS, CID and IDM ENABLE circuit faults.
Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent Scan Tool