Operation CHARM: Car repair manuals for everyone.

Without Using M-MDS

PCM INSPECTION [L3]

Without Using M-MDS

NOTE: The PCM terminal voltage can vary with the conditions when measuring and changes due to aged deterioration on the vehicle, causing false diagnosis. Therefore determine comprehensively where the malfunction occurs among the input systems, output systems, and the PCM.




Terminal 1A-1B:




Terminal 1C-1AJ:




Terminal 1AK-1BB:




Terminal 1BC-2S:




Terminal 2T-2AN:




Terminal 2AO-2BH:





Inspection Using An Oscilloscope (Reference)
Cooling fan control signal




PCM terminals
- 1 R (+)-body ground (-)
Oscilloscope setting
- 5 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

Purge control signal




PCM terminals
- 2C (+)-body ground (-)
Oscilloscope setting
- 2 V/DIV (Y), 10 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

APP sensor signal
Accelerator pedal is released

Accelerator pedal is depressed




PCM terminals
- 1AO (+)-body ground (-)
Oscilloscope setting
- 2.5 V/DIV (Y), 2 ms/DIV (X), DC range
Vehicle condition
- Ignition switch is turned to the ON position.
(engine off)

OCV signal




PCM terminals
- 2E (+)-body ground (-)
Oscilloscope setting
- 2 V/DIV (Y), 0.8 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

CMP signal




PCM terminals
- 2S (+)-body ground (-)
Oscilloscope setting
- 1 V/DIV (Y), 25 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

CKP signal




PCM terminals
- 2W (+)-body ground (-)
Oscilloscope setting
- 1 V/DIV (Y), 2.5 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

Generator field coil control signal




PCM terminals
- 2M (+)-body ground (-)
Oscilloscope setting
- 0.5 V/DIV (Y), 2 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up (engine speed approx. 650 rpm, no load, A/C off)

Generator output voltage signal




PCM terminals
- 2AF (+)-body ground (-)
Oscilloscope setting
- 2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

IGT1, IGT2, IGT3, IGT4 signals




PCM terminals
- IGT1 (No.1): 2G (+)-body ground (-)
- 10T2 (No.2): 2K (+)-body ground (-)
- IGT3 (No.3): 2L (+)-body ground (-)
- IGT4 (No.4): 2H (+)-body ground (-)

Oscilloscope setting
- 4 V/DIV (Y), 0.01 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

Fuel injection signal




PCM terminals
- Fuel Injection No.1: 2BB (+)-body ground (-)
- Fuel Injection No.2: 2BC (+)-body ground (-)
- Fuel Injection No.3: 2BD (+)-body ground (-)

Oscilloscope setting
- 4V/DIV (Y), 20 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up

Front HO2S heater control signal




PCM terminals
- 2A (+)-body ground (-)
Oscilloscope setting
- 5 V/DIV (Y), 200 ms/DIV (X), DC range
Vehicle condition
- Idle after warm up (engine speed approx. 650 rpm, no load, A/C off)

Rear HO2S heater control signal




PCM terminals
- 2B (+)-body ground (-)
Oscilloscope setting
- 5 V/DIV (Y), 1 s/DIV (X), DC range
Vehicle condition
- Idle after warm up (engine speed approx. 650 rpm, no load, A/C off)