Part 1

DIAGNOSTIC ITEM 4: Diagnose shorts in the ground to CAN-C bus line.

FUNCTION

If a short to ground is present in the CAN-C lines, this diagnosis result will be set.

TROUBLE JUDGMENT CONDITIONS

If DTC U1120 is set, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS

- Malfunction of the connector (short to ground inside connector)

- Malfunction of the wiring harness (short to ground in the CAN-C main or sub bus lines)

- Malfunction of the ECU (ETACS-ECU, or ECUs on CAN-C lines failed)

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set

- MB992006: Extra Fine Probe

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)

- MB991827: M.U.T.-III USB Cable

- MB991910: M.U.T.-III Main Harness A

- MB991974: ABS Check Harness

- MB991997: ASC Check Harness

- MB992110: Power Plant ECU Check Harness

STEP 1. Check the wiring harness between joint connector (CAN2) C-05 and steering wheel sensor connector C-211 for a short to ground. Measure the resistance at joint connector (CAN2) C-05.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).

(2)Measure the resistance between joint connector (CAN2) terminal 9 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN2) terminal 20 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES [except RALLIART (FWD)] : Go to Step 4.

YES [except RALLIART (AWD)] : Go to Step 3.

YES [RALLIART] : Go to Step 2.

NO : Go to Step 14.

STEP 2. Check the wiring harness between joint connector (CAN2) C-05 and AWC-ECU connector C-51 for a short to ground. Measure the resistance at joint connector (CAN2) C-05.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).

(2)Measure the resistance between joint connector (CAN2) terminal 8 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN2) terminal 19 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 6.

NO Go to Step 15.

STEP 4. Check the wiring harness between joint connector (CAN2) C-05 and no connection connector C-144 for a short to ground. Measure the resistance at joint connector (CAN2) C-05.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).

(2)Measure the resistance between joint connector (CAN2) terminal 7 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN2) terminal 18 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 5.

NO Repair the wiring harness between joint connector (CAN2) C-05 and no connection connector C-51.

STEP 5. Check the wiring harness between joint connector (CAN2) C-05 and ETACS-ECU connector C-301 for a short to ground. Measure the resistance at joint connector (CAN2) C-05.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN2), and measure the resistance at the wiring harness side of joint connector (CAN2).

(2)Measure the resistance between joint connector (CAN2) terminal 11 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN2) terminal 22 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 6.

NO Go to Step 17.

STEP 6. Check the wiring harness between joint connector (CAN3) C-124 and ABS-ECU connector A-03 [vehicles without ASC] or ASC-ECU connector A-51 [vehicles with ASC] for a short to ground. Measure the resistance at joint connector (CAN3) C-124.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).

(2)Measure the resistance between joint connector (CAN3) terminal 9 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN3) terminal 20 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES [except RALLIART] : Go to Step 7.

YES [RALLIART] : Go to Step 10.

NO : Go to Step 18.

STEP 7. Check the wiring harness between joint connector (CAN3) C-124 and TCM connector C-41 for a short to ground. Measure the resistance at joint connector (CAN3) C-124.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).

(2)Measure the resistance between joint connector (CAN3) terminal 8 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN3) terminal 19 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 8.

NO Go to Step 19.

STEP 8. Check the wiring harness between joint connector (CAN3) C-124 and ECM connector B-109 [except RALLIART] for a short to ground. Measure the resistance at joint connector (CAN3) C-124.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).

(2)Measure the resistance between joint connector (CAN3) terminal 10 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN3) terminal 21 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 9.

NO Go to Step 20.

STEP 9. Check the wiring harness between joint connector (CAN3) C-124 and electric power steering-ECU connector C-141 [vehicles with electric power steering]
for a short to ground. Measure the resistance at joint connector (CAN3) C-124.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).

(2)Measure the resistance between joint connector (CAN3) terminal 6 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN3) terminal 17 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Check intermediate connector C-127, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN2) C-05 and joint connector (CAN3) C-124.

NO Go to Step 21.

STEP 10. Check the wiring harness between joint connector (CAN3) C-124 and shift lever connector C-49 for a short to ground. Measure the resistance at joint connector (CAN3) C-124.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN3), and measure the resistance at the wiring harness side of joint connector (CAN3).

(2)Measure the resistance between joint connector (CAN3) terminal 7 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN3) terminal 18 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 11.

NO Go to Step 22.

STEP 11. Check the wiring harness between joint connector (CAN4) A-55 and ECM connector B-109 [RALLIART] for a short to ground. Measure the resistance at joint connector (CAN4) A-55.

CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
A digital multimeter should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

CAUTION:
The test wiring harness should be used. For details refer to Precautions When CAN Bus Line(s) are Repaired.

(1)Disconnect joint connector (CAN4), and measure the resistance at the wiring harness side of joint connector (CAN4).

(2)Measure the resistance between joint connector (CAN4) terminal 6 and body ground.
OK: 1 kohms or more

(3)Measure the resistance between joint connector (CAN4) terminal 19 and body ground.
OK: 1 kohms or more

Q. Do all the resistances measure 1 kohms or more?

YES Go to Step 12.

NO Go to Step 20.