Locating the source of unusual signals
CAUTION:
- Compare the WDS or equivalent monitor voltage with the measurement voltage using the digital measurement system function. If you use another tester, misreading may occur.
- When measuring voltage, attach the tester GND to the GND of the PCM that is being tested, or to the engine itself. If this is not performed, the measured voltage and actual voltage may differ.
- After connecting the pin to a waterproof coupler, confirming continuity and measuring the voltage, inspect the waterproof connector for cracks. If there are any, use sealant to fix them. Failure to do this may result in deterioration of the wiring harness or terminal from water damage, leading to problems with the vehicle.
Variable resistance type 1 (TP sensor and EGR boost sensor)
Input signal system inspection for variable resistance type 1
- When an irregular signal is detected, measure the #1 PCM terminal voltage.
- If the #1 terminal voltage and the WDS or equivalent monitor voltage are the same, proceed to the next step.
- If there is a difference of 0.5 V or more
, inspect for the following points concerning the PCM connector:
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- Harness/pin crimp is loose or disconnected.
- Measure the #2 sensor terminal voltage.
- If there is a 0.5 V or more difference between the sensor and the WDS or equivalent voltages, inspect the wiring harness for open or short circuits.
- If the sensor and the WDS or equivalent voltages are the same, inspect for the following points concerning the sensor connector:
- Female terminal opening is loose.
- Coupler (pin holder) damage
- Pin discoloration (blackness)
- If there are no problems, proceed to next investigation below.