Test Description
The numbers below refer to the circled numbers in the diagnostic flow chart.
- This step verifies proper operation of circuits 633, 644, and 645. (Scheme 82)for circuit identification.
- Step validates the integrity of Circuit 630 from the ignition module to the ECM. (Scheme 83)for circuit identification.
- If the camshaft gear magnet is interfacing with the cam sensor the voltage reading will be zero, bumping engine will cause the condition to go away.
- If the voltage reading of terminal "BC5" is constantly varying and connection to terminal "BC5" are good, the ECM is faulty.
An intermittent may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside the insulation.
Check for the following
- Poor Connection or Damaged Harness: Inspect ECM harness connectors for backed out terminal "BC5", improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.
- Intermittent Test: If connections and harness check okay, monitor a digital voltmeter connected from ECM terminal "BC5" to ground while moving related connectors and wiring harness. If failure is induced, voltage reading will change. This may help to isolate the location of the malfunction.
Note. For Supplemental Wiring Schematic below the letter "B" on PCM connector terminal designates black connector.
