Pinpoint Test D: The Heated Exterior Rear View Mirror is Inoperative

Rear View Mirrors - Exterior

Pinpoint Test D: The Heated Exterior Rear View Mirror is Inoperative

Refer to Wiring Diagram Set 56, Heated Window for schematic and connector information Electrical Diagrams.

Refer to Wiring Diagram Set 124, Power Mirrors for schematic and connector information Electrical Diagrams.

Normal Operation

Under normal operation, when the rear window defrost switch is pressed to the ON position, the rear window defrost relay closes and voltage is supplied to Central Junction Box (CJB) fuse 25 (7.5A) to power the LH and RH exterior rear view mirrors. The exterior rear view mirrors do not share a common ground.

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- Exterior rear view mirror glass

PINPOINT TEST D : THE HEATED EXTERIOR REAR VIEW MIRROR IS INOPERATIVE

D1 CHECK THE OPERATION OF THE REAR WINDOW DEFROST SYSTEM

- With the engine running, activate the rear window defrost switch to the ON position.

- Using a infrared temperature gun or equivalent measure the temperature of the rear window glass for approximately 30 seconds noting changes in temperature.

Does the temperature of the rear window glass rise?

Yes
GO to D2.

No
REFER to Windows and Glass to diagnose the rear window defrost system.

D2 CHECK THE OPERATION OF THE HEATED EXTERIOR REAR VIEW MIRRORS

- With the rear window defrost switch in the ON position, using a infrared temperature gun or equivalent measure the temperature of the RH and LH exterior rear view mirror glass for approximately 30 seconds noting changes in temperature.

Does at least one heated mirror glass operate correctly?

Yes
GO to D3.

No
VERIFY that CJB (Central Junction Box) fuse 25 (7.5A) is OK. If OK, REPAIR circuit CRD06 (BN/YE) for an open. If not OK, REPAIR circuit CBP25 (WH/OG) harness side for a short to ground. TEST the system for normal operation.

D3 CHECK THE VOLTAGE TO THE INOPERATIVE HEATED EXTERIOR REAR VIEW MIRROR GLASS

- Ignition ON.

- Disconnect: Inoperative Heated Exterior Rear View Mirror C521(LH) or C601(RH).

- NOTE: The rear window defrost system activates for 10 minutes.
With the engine running, press the rear window defrost switch to the ON position.


- Measure the voltage between:
- LH exterior rear view mirrorC521-1, circuit CBP25 (WH/OG), harness side and ground.

- RH exterior rear view mirrorC601-1, circuit CBP25 (WH/OG), harness side and ground.






Is the voltage greater than 10 volts?

Yes
GO to D4.

No
REPAIR the circuit for an open. TEST the system for normal operation.

D4 CHECK THE INOPERATIVE EXTERIOR REAR VIEW MIRROR GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.

- Measure the resistance between:
- LH exterior rear view mirrorC521-2, circuit GD143 (BK/VT), harness side and ground.

- RH exterior rear view mirrorC601-2, circuit GD145 (BK/BU), harness side and ground.






Is the resistance less than 5 ohms?

Yes
INSTALL a new exterior rear view mirror glass. REFER to Exterior Mirror Glass Exterior Mirror Glass. TEST the system for normal operation.

No
REPAIR the circuit for an open. TEST the system for normal operation.