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 "Signal Circuit Inspection" procedure.

Signal Circuit Inspection

CAUTION:
This procedure is applied to vehicle with ABS (or ESC)
In case of no ABS (or ESC), refer to "C1203 Wheel speed sensor front-RH open/short".

1. Check short to ground in harness
(1) IG "OFF"
(2) Disconnect ECM connector and ABS or ESC control module connector.
(3) Measure resistance between terminal 52 of ECM harness connector and chassis ground.
A. Specification : Infinite




(4) Is the measured resistance within specifications?
YES
- Go to "Check open in harness" as follows.
NO
- Repair short to ground in harness and go to "Verification of Vehicle Repair" procedure.
2. Check for open in harness
(1) Ignition "OFF"
(2) Disconnect ECM connector and ABS or ESC control module connector.
(3) Measure resistance between terminal "52" of ECM harness connector and terminal "21" of ESC control module harness connector.
A. Specification : Approx. below 1 Ohms





CAUTION:
This picture is only applied to vehicle with ESC

(4) Is the measured resistance within specifications?
YES
- Go to "Check wheel speed sensor" procedure.
NO
- Check open in harness.
- Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
3. Check wheel speed sensor
(1) IG "OFF"
(2) Check open or short in wheel speed sensor C1209
(3) Is the wheel speed sensor normal?
YES
- Substitute with a known-good ECM/ESC control unit and check for proper operation.
If the problem is corrected, replace ECM/ABS or ESC control unit and go to "Verification of Vehicle Repair" procedure.
NO
- Repair or replace it 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 ECM. After testing ECM on the vehicle, use this function to reuse the ECM on the others