W/Harness Inspection

P0642 Sensor Reference Voltage A Circuit Low

Inspection/Repair - W/Harness Inspection

Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
1) Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Power circuit inspection" procedure.

Power Supply Circuit Inspection

1. Check voltage
(1) IG "OFF".
(2) Disconnect IATS, ECTS, TPS and FTPS harness connector.
(3) IG "ON".
(4) Measure the voltage between terminal 3 of IATS harness connector and ground.
Measure the voltage between terminal 1 of ECTS harness connector and ground.
Measure the voltage between terminal 2 of TPS harness connector and ground.
Measure the voltage between terminal 3 of FTPS harness connector and ground.
A. Specification : approx. 5 V








(5) Is the measured voltage within specification?
YES
1) Thoroughly check connectors for looseness, poor connection, bending, corrosion contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Check Short to ground" procedure.
2. Check Short to ground
(1) IG "OFF".
(2) Disconnect IATS, ECTS, TPS, FTPS and ECM harness connector.
(3) Measure the resistance between terminal 3 of IATS harness connector and ground.
Measure the resistance between terminal 1 of ECTS harness connector and ground.
Measure the resistance between terminal 2 of TPS harness connector and ground.
Measure the resistance between terminal 3 of FTPS harness connector and ground.
A. Specification : Infinite








(4) Is the resistance within specification?
YES
1) This DTC is caused by Open in power circuit or Malfunction of PCM. so, Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

CAUTION:
There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM.
Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others

NO
1) Repair Short to ground in power circuit and then go to "Verification of Vehicle Repair" procedure.