Pinpoint Test D: The Heated Exterior Mirror is Inoperative
Rear View Mirrors - Exterior
Pinpoint Test D: The Heated Exterior Mirror is Inoperative
Refer to Wiring Diagram Set 56, Heated Windows 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 depressed to the ON position, the rear window defrost relay closes and voltage is supplied to Battery Junction Box (BJB) fuse 1 (15A). The heated exterior mirrors receive voltage from BJB (Battery Junction Box) fuse 1 (15A) through circuit CBB01 (BU). Ground is supplied to the LH and RH heated exterior mirrors through circuit GD149 (BK/GY).
This pinpoint test is used to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Exterior mirror glass
- Exterior mirror
PINPOINT TEST D : THE HEATED EXTERIOR MIRROR IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
D1 CHECK THE OPERATION OF THE HEATED EXTERIOR MIRROR GLASS
- Start the engine.
- Press the rear window defrost switch to the ON position.
- Using an infrared temperature gun, measure the temperature of the exterior mirror glass for approximately 30 seconds noting changes in temperature.
Does the temperature of the exterior glass rise?
Yes
The system is operating correctly at this time.
No
GO to D2.
D2 CHECK THE OPERATION OF THE REAR WINDOW DEFROST SYSTEM
- Using an infrared temperature gun, measure the temperature of the rear window for approximately 30 seconds noting changes in the temperature.
Does the temperature of the rear window rise?
Yes
GO to D3.
No
REFER to Windows and Glass to diagnose the rear window defrost system.
D3 CHECK THE VOLTAGE TO THE INOPERATIVE EXTERIOR MIRROR
- Ignition OFF.
- Disconnect: Inoperative Exterior Mirror C520 (LH) or C601 (RH).
- With the engine running, depress the rear window defrost switch to the ON position.
- Measure the voltage between ground and inoperative exterior mirror:
- LH exterior mirror:C520-4, circuit CBB01 (BU), harness side.
- RH exterior mirror:C601-4, circuit CBB01 (BU), harness side.
Is the voltage greater than 10 volts?
Yes
GO to D4.
No
INSPECT BJB (Battery Junction Box) fuse 1 (15A). If OK, GO to D5. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.
D4 CHECK THE INOPERATIVE EXTERIOR MIRROR GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between ground and inoperative exterior mirror:
- LH exterior mirror:C520-5, circuit GD149 (BK/GY), harness side.
- RH exterior mirror:C601-5, circuit GD149 (BK/GY), harness side.
Is the resistance less than 5 ohms?
Yes
CHECK the LH or RH exterior mirror jumper harness between the vehicle harness and the exterior mirror motor for open or shorted circuits and damaged or pushed-out pins. If the jumper harness is not OK, REPAIR the jumper harness. If the jumper harness cannot be repaired, INSTALL a new LH or RH exterior mirror. REFER to Exterior Mirror . If the jumper harness is OK, INSTALL a new exterior mirror glass. REFER to Exterior Mirror Glass . TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
D5 CHECK CIRCUIT CBB01 (BU) FOR AN OPEN
- Ignition OFF.
- Disconnect: Rear Window Defrost Relay.
- Measure the resistance between BJB (Battery Junction Box) rear window defrost relay pin 5, harness side and inoperative exterior mirror:
- LH exterior mirror:C520-4, circuit CBB01 (BU), harness side.
- RH exterior mirror:C601-4, circuit CBB01 (BU), harness side.
Is the resistance less than 5 ohms?
Yes
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.