FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Part 2




STEP 11. Check the A/C-ECU for a short to ground.





(1)Disconnect A/C-ECU connector C-14 [manual air conditioning system] or C-15 [automatic air conditioning system].





(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 A/C-ECU connector.

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

STEP 12. Check the SRS-ECU for a short to ground.





(1)Disconnect SRS-ECU connector C-123.





(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 SRS-ECU connector.

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

STEP 13. Check the TPMS receiver for a short to ground.





(1)Disconnect TPMS receiver connector C-121.





(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 TPMS receiver connector.

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

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.





(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 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.





(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 Return to Step 1.

NO Go to Step 24.

STEP 23. 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 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. Encrypted Code Registration Criteria Table.