W/Harness Inspection

Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. 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 then go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Signal Circuit Inspection" procedure.

Signal Circuit Inspection

1. Ignition "ON" & Engine "OFF".
2. Put and release the brake pedal several times.
3. Measure voltage, waveform between terminal "20,23" of the HECU harness connector and chassis ground.
A. Specification : 0.5V ~ 4.4V
Approx. 0.5V (in case of no braking)




4. Is the measured voltage within specifications?
YES
1) Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure.
NO
1) Check for open or short in pressure sensor harness between terminal "1" of the pressure sensor A,B harness connector and terminal "20,23" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
2) Go to "Component Inspection" procedure.