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
- Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
- Go to "Power Circuit Inspection" procedure.

Power Supply Circuit Inspection

1. Check voltage
(1) IG "OFF".
(2) Disconnect the ECM connector.
(3) IG "ON" and ENG "OFF"
(4) During taking off the brake : Measure the voltage between terminal 23 of ECM harness connector and chassis ground.
(5) During stepping on the brake : Measure the voltage between terminal 23 of ECM harness connector and chassis ground.
A. Specification :









(6) Is the measured voltage within specification?
YES
- Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
- Go to "Check open in harness" as follows.
2. Check open in harness
(1) IG "OFF".
(2) Disconnect the brake switch and ECM connector.
(3) Measure the resistance between terminal 23 of ECM harness connector and terminal 3 of Brake switch harness connector.
A. Specification : Approx. below 1 Ohm




(4) Is the measured resistance within specification?
YES
- Go to "Check Battery voltage" as follows.
NO
- Repair open in harness and go to "Verification of Vehicle Repair" procedure.
3. Check Battery voltage
(1) IG "OFF".
(2) Disconnect the brake switch connector.
(3) Measure the voltage between brake switch harness connector terminal 1 and chassis ground.
(4) Measure the voltage between brake switch harness connector terminal 2 and chassis ground.
(5) IG Key "ON".
(6) Measure the voltage between brake switch harness connector terminal 1 and chassis ground.
(7) Measure the voltage between brake switch harness connector terminal 2 and chassis ground.
A. Specification :













(8) Is the measured voltage within specification?
YES
- Substitute with a known-good brake switch and check for proper operation. If the problem is corrected, replace brake switch and go to "Verification of Vehicle Repair" procedure.
NO
- Check the fuse between battery and brake switch.
- Repair open or short in power circuit of brake switch and go to "Verification of Vehicle Repair" procedure.