Diagnostic Aids
Scan tester does not have the ability to help diagnose Code 23. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connections or damaged harness.
Perform intermittent check by monitoring circuit and code status while wiggling related wiring and connectors. If failure is induced, monitored circuit status will change rapidly and/or related code will set.
- 6) Checks if by-pass is being sent by PCM to the ignition module. If by-pass is being sent, voltage will be greater than 4.1 volts.
- 7) Checks if by-pass control sent by PCM is being received by ignition module. If by-pass circuit is okay, resistance will be less than 5 ohms.
- 8) Checks if PCM is providing proper signal to ignition module. If PCM terminal F3 has 30-100 hertz, PCM is not at fault.
- 9) Checks if PCM can produce the proper ignition control pulses. If max voltage exceeds 3.7 volts, PCM is okay and ignition module is at fault.
- 10) Checks by-pass circuit for short to ground.
- 11) Checks if ignition module is able to recognize a by-pass signal. If it does, code will not set again. If code resets, ignition module is faulty.
- 12) Checks if ignition module is causing incorrect voltage or if PCM is supplying incorrect signal.
Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connections or damaged harness. Perform intermittent check by monitoring circuit and code status while wiggling related wiring and connectors. If failure is induced, monitored circuit status will change rapidly and/or related code will set.