Part 3

DIAGNOSTIC ITEM 2: Diagnose shorts in the ground to CAN bus line (Continued)

STEP 14. Check the steering wheel sensor for a short to ground.

(1)Disconnect steering wheel sensor connector C-312.

(2)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958 to the data link connector.

(3)Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration.

Q. Does scan tool MB991958 screen correspond to the illustration?

YES Repair the wiring harness between joint connector (3) and the steering wheel sensor connector.

NO Check the steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, replace the steering wheel sensor.

STEP 15. Check the CAN line between intermediate connector C-24 and TCL/ASC-ECU connector A-38 for a short to ground. Measure the resistance at intermediate connector C-24.

(1)
CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

Disconnect the negative battery terminal.

(2)Disconnect intermediate connector C-24 and TCL/ASC-ECU connector A-38, and measure the resistance at the male side of intermediate connector C-24 (at front wiring harness side).

(3)Measure the resistance between intermediate connector terminal 11 (CAN_H) and body ground.
OK: 1 kohms or more

(4)Measure the resistance between intermediate connector terminal 12 (CAN_L) and body ground.
OK: 1 kohms or more

CAUTION:
Strictly observe the specified wiring harness repair procedure. For details refer to Precautions on How to Repair the CAN Bus Line(s).

Q. Is the check result normal?

YES Go to Step 19.

NO Repair the wiring harness.

STEP 16. Check the CAN line of the front wiring harness for a short to the power supply. Measure the resistance at intermediate connector C-26.

(1)Disconnect intermediate connector C-26, and measure the resistance at the male side (at floor wiring harness side).
(2)Turn the ignition switch to the "ON" position.

(3)Measure the resistance between intermediate connector terminal 15 (CAN_H) and body ground.
OK: 1 kohms or more

(4)Measure the resistance between intermediate connector terminal 16 (CAN_L) and body ground.
OK: 1 kohms or more

Q. Is the check result normal?

YES Go to Step 19.

NO Go to Step 17.

STEP 17. Check the CAN line between intermediate connector C-26 and convertible top control module connector D-45 for a short to ground. Measure the resistance at intermediate connector C-26.

(1)
CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

Disconnect the negative battery terminal.

(2)Disconnect intermediate connector C-26 and convertible top control module connector D-45, and measure the resistance at the male side of intermediate connector C-26 (at floor wiring harness side).

(3)Measure the resistance between intermediate connector terminal 15 (CAN_H) and body ground.
OK: 1 kohms or more

(4)Measure the resistance between intermediate connector terminal 16 (CAN_L) and body ground.
OK: 1 kohms or more

CAUTION:
Strictly observe the specified wiring harness repair procedure. For details refer to Precautions on How to Repair the CAN Bus Line(s).

Q. Is the check result normal?

YES Go to Step 18.

NO Repair the wiring harness.

STEP 18. Check the CAN line between intermediate connector C-23 and convertible top control module connector D-45 for a short to ground. Measure the resistance at intermediate connector C-23.

(1)
CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

Disconnect the negative battery terminal.

(2)Disconnect intermediate connector C-23 and convertible top control module connector D-45, and measure the resistance at the male side of intermediate connector C-23 (at floor wiring harness side).

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

(4)Measure the resistance between intermediate connector terminal 23 (CAN_L) and body ground.
OK: 1 kohms or more

CAUTION:
Strictly observe the specified wiring harness repair procedure. For details refer to Precautions on How to Repair the CAN Bus Line(s).

Q. Is the check result normal?

YES Check the convertible top control module connector D-45, and repair if necessary. If the convertible top control module connector D-45 is in good condition, replace the convertible top control module.

NO Repair the wiring harness.

STEP 19. Check the CAN line between the ECM [M/T] or PCM [A/T] connector B-18 and TCL/ASC-ECU connector A-38 for a short to ground. Measure the resistance at ECM [M/T] or PCM [A/T] connector B-18.

(1)
CAUTION:
Disconnect the negative battery terminal. For details refer to Precautions When CAN Bus Line(s) are Repaired.

Disconnect the negative battery terminal.

(2)Disconnect ECM [M/T] or PCM [A/T] connector B-18 and TCL/ASC-ECU connector A-38, and measure the resistance at the harness side of ECM [M/T] or PCM [A/T] connector B-18.

(3)Measure the resistance between ECM [M/T] or PCM [A/T] connector terminal 17 and body ground.
OK: 1 kohms or more

(4)Measure the resistance between ECM [M/T] or PCM [A/T] connector terminal 18 and body ground.
OK: 1 kohms or more

CAUTION:
Strictly observe the specified wiring harness repair procedure. For details refer to Precautions on How to Repair the CAN Bus Line(s).

Q. Is the check result normal?

YES Go to Step 20.

NO Repair the wiring harness between ECM [M/T] or PCM [A/T] connector and TCL/ASC-ECU connector.

STEP 20. Retest the system.

(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958 to the data link connector.
(2)Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state.

Q. Is the check result normal?

YES Intermittent malfunction.

NO Check the TCL/ASC-ECU connector, and repair if necessary. If the TCL/ASC-ECU connector is in good condition, replace the TCL/ASC-ECU.

STEP 21. Check the combination meter for a short to ground.

(1)Disconnect combination meter connector C-04.

(3)Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration.

Q. Does scan tool MB991958 screen correspond to the illustration?

YES Go to Step 22.

NO Go to Step 23.

STEP 22. Check the ECM [M/T] or PCM [A/T] for a short to ground.

(1)Disconnect ECM [M/T] or PCM [A/T] connector B-18.

(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958 to the data link connector.
(2)Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state.

Q. Is the check result normal?

YES Intermittent malfunction.

NO Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.

STEP 24. Retest the system.

(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958 to the data link connector.
(2)Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state.

Q. Is the check result normal?

YES Intermittent malfunction.

NO Check the ECM [M/T] or PCM [A/T] connector, and repair if necessary. If the ECM [M/T] or PCM [A/T] connector is in good condition, replace the ECM [M/T] or PCM [A/T]. When the ECM [M/T] or PCM [A/T] is replaced, register the encrypted code. Immobilizer System.