Rear View Mirrors - Interior
Rear View Mirrors - Interior
Pinpoint Tests
Pinpoint Test H: The Auto-Dimming Mirror Does Not Operate Correctly
Refer to Wiring Diagram Set 124, Power Mirrors for schematic and connector information. Diagrams By Number
Normal Operation
The interior auto-dimming mirror contains 2 photoelectric sensors: one in the front of the interior rear view mirror and one mounted on the glass side of the mirror. If the sensors are blocked, the LH exterior mirror and interior mirror auto-dimming feature may not operate correctly. Always verify both sensors are not physically blocked before attempting to diagnose auto-dimming mirror concerns.
For vehicles equipped with an interior mirror with compass display, whenever the gear selector lever is placed in REVERSE the Body Control Module (BCM) communicates selector position to the interior rear view mirror via the Local Interconnect Network (LIN) to disable the auto-dimming feature.
For vehicles equipped with an interior mirror without compass display, whenever the gear selector lever is placed in REVERSE the interior rear view mirror temporarily disables the auto-dimming feature via the reverse circuit input received from the BCM.
The auto-dimming feature is enabled again when the gear selector lever is moved out of REVERSE.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Interior auto-dimming mirror
- LH auto-dimming exterior mirror glass
- LH auto-dimming exterior mirror
PINPOINT TEST H: THE AUTO-DIMMING MIRROR DOES NOT OPERATE CORRECTLY
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H1 VERIFY THE FORWARD AND REARWARD FACING SENSORS ARE NOT BLOCKED
- Visually verify the forward and rearward facing sensors are not blocked. Sources of blockage can include:
- stickers, window decals or tags.
- fold-down screens for TVs or DVD players.
- non-OEM window tinting.
- Were either of the sensors blocked?
Yes
If possible, REMOVE the blockage. TEST the system for normal operation. If it is not possible to remove the blockage, ADVISE the customer of the correct operation of the interior auto-dimming mirror.
No
GO to H2.
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H2 CHECK OPERATION OF THE BACKUP LAMPS
- Ignition ON.
- Move the selector lever through the entire range.
- Do the backup lamps illuminate and only in REVERSE?
Yes
If both the LH exterior mirror and interior mirror do not dim correctly, GO to H3. If only the LH exterior mirror does not dim correctly, GO to H9. If only the interior mirror does not dim correctly:
- For vehicles equipped with an interior mirror with compass display, , GO to H17.
- For vehicles equipped an interior mirror without compass display, GO to H18.
No
REFER to Exterior Lighting Testing and Inspection to diagnose the backup lamps.
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H3 CHECK OPERATION OF THE INTERIOR AUTO-DIMMING MIRROR - DAYLIGHT CONDITIONS
- Use a bright lamp to illuminate the forward facing sensor. The mirror should adjust to a high reflectance mode (mirror will be clear).
- Does the mirror adjust to the high reflectance (clear) mode?
Yes
GO to H4.
No
INSTALL a new interior rear view mirror. REFER to Interior Rear View Mirror Interior Rear View Mirror. TEST the system for normal operation.
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H4 CHECK OPERATION OF THE INTERIOR AUTO-DIMMING MIRROR - NIGHTTIME CONDITIONS WITH GLARE
- NOTE: Covering the sensor with a finger or hand is not adequate.
- Simulate nighttime conditions with glare:
- cover the forward sensor with black electrical tape or other dark material.
- illuminate the rearward facing sensor. The mirror should darken to a lower reflectance mode.
- Did the mirror darken to a lower reflectance (darker) mode?
Yes
GO to H5.
No
GO to H7.
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H5 CHECK OPERATION OF THE INTERIOR AUTO-DIMMING MIRROR - NIGHTTIME CONDITIONS WITHOUT GLARE
- NOTE: Covering the sensor with a finger or hand is not adequate.
- Simulate nighttime conditions without glare:
- cover the rearward facing sensor. The mirror should adjust to the high reflectance mode.
- Did the mirror adjust to the high reflectance (clear) mode?
Yes
GO to H6.
No
GO to H7.
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H6 CHECK OPERATION OF THE INTERIOR AUTO-DIMMING MIRROR - NIGHTTIME CONDITIONS WITH THE VEHICLE IN REVERSE
- NOTE: Covering the sensor with a finger or hand is not adequate.
- Simulate nighttime conditions with glare:
- cover the forward sensor with black electrical tape or other dark material.
- illuminate the rearward facing sensor. (mirror should darken at this time).
- Select REVERSE.
- Did the mirror adjust to a high reflectance (clear) mode?
Yes
The system is operating normally at this time. ADVISE the customer of the correct operation of the interior auto-dimming mirror.
No
GO to H7.
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H7 CHECK FOR VOLTAGE TO THE INTERIOR AUTO-DIMMING MIRROR
- Ignition OFF.
- Disconnect: Interior Auto-Dimming Mirror C9039.
- Ignition ON.
- Measure the voltage between interior auto-dimming mirror C9039-1, circuit CBP32 (GN/VT), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to H8.
No
VERIFY that Body Control Module (BCM) fuse 32 (15A) is OK. If OK, REPAIR the circuit for an open. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. TEST the system for normal operation. Diagrams By Number
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H8 CHECK FOR GROUND TO THE INTERIOR AUTO-DIMMING MIRROR
- Ignition OFF.
- Measure the resistance between interior auto-dimming mirror C9039-4, circuit GD133 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL new interior rear view mirror. REFER to Interior Rear View Mirror Interior Rear View Mirror.
No
REPAIR the circuit. TEST the system for normal operation.
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H9 CHECK THE INTERIOR REAR VIEW MIRROR OUTPUT TO THE LH EXTERIOR REAR VIEW MIRROR
- Ignition OFF.
- Disconnect: LH Exterior Rear View Mirror C521.
- Ignition ON.
- NOTE: Covering the sensor with a finger or hand is not adequate.
- Simulate nighttime conditions with glare:
- cover the forward facing sensor with black electrical tape or other dark material.
- illuminate the rearward facing sensor. The interior mirror should darken to a lower reflectance mode.
- Measure the voltage between LH exterior mirror C521-9, circuit LRD12 (BU/GY), harness side and ground.
- Is the voltage greater than 1 volt?
Yes
GO to H10.
No
GO to H15.
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H10 CHECK THE GROUND CIRCUIT BETWEEN THE LH EXTERIOR REAR VIEW MIRROR AND INTERIOR REAR VIEW MIRROR FOR A SHORT TO VOLTAGE
- Measure the voltage between LH exterior rear view mirror C521-2, circuit RRD12 (BN), harness side and ground.
- Is any voltage present?
Yes
GO to H11.
No
GO to H12.
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H11 ISOLATE THE SHORT TO VOLTAGE ON THE GROUND CIRCUIT
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C9039.
- Ignition ON.
- Measure the voltage between LH exterior mirror C521-2, circuit RRD12 (BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
INSTALL a new interior rear view mirror. REFER to Interior Rear View Mirror Interior Rear View Mirror. TEST the system for normal operation.
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H12 CHECK THE GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between LH exterior mirror C521-9, circuit LRD12 (BN), harness side and LH exterior mirror C521-2, circuit RRD12 (BN), harness side.
- Is the voltage greater than 1 volt?
Yes
CHECK the LH exterior mirror jumper harness between the vehicle harness and the exterior mirror glass for shorted or open 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 exterior mirror. REFER to Exterior Mirror Exterior Mirror. If the jumper harness is OK, INSTALL a new LH exterior mirror glass. REFER to Exterior Mirror Glass Exterior Mirror Glass. TEST the system for normal operation.
No
GO to H13.
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H13 CHECK THE GROUND CIRCUIT BETWEEN THE EXTERIOR REAR VIEW MIRROR AND INTERIOR AUTO-DIMMING MIRROR FOR AN OPEN
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C9039.
- Measure the resistance between interior rear view mirror C9039-15, circuit RRD12 (BN), harness side and LH exterior mirror C521-2, circuit RRD12 (BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to H14.
No
REPAIR the circuit for an open. TEST the system for normal operation.
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H14 CHECK THE CIRCUIT BETWEEN THE LH EXTERIOR REAR VIEW MIRROR AND INTERIOR REAR VIEW MIRROR FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C9039.
- Measure the resistance between LH exterior mirror C521-9, circuit LRD12 (BU/GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to H15.
No
REPAIR the circuit. TEST the system for normal operation.
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H15 CHECK THE CIRCUIT BETWEEN THE LH EXTERIOR REAR VIEW MIRROR AND INTERIOR REAR VIEW MIRROR FOR AN OPEN
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C9039 (if not previously disconnected).
- Measure the resistance between interior rear view mirror C9039-11, circuit LRD12 (BU/GY), harness side and LH exterior mirror C521-9, circuit LRD12 (BU/GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to H16.
No
REPAIR the circuit for an open. TEST the system for normal operation.
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H16 CHECK FOR A SHORT BETWEEN THE LH EXTERIOR REAR VIEW MIRROR AND INTERIOR REAR VIEW MIRROR CIRCUITS
- Measure the resistance between LH rear view mirror C521-2, circuit RRD12 (BU/GY), and LH exterior mirror C521-9, circuit LRD12 (BU/GY), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new interior rear view mirror. REFER to Interior Rear View Mirror Interior Rear View Mirror. TEST the system for normal operation.
No
REPAIR the circuits. TEST the system for normal operation.
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H17 CHECK THE LIN CIRCUIT FOR CORRECT OPERATION
- Position the vehicle and observe the compass display.
- Does the compass display correctly?
Yes
INSTALL a new interior rear view mirror. REFER to Interior Rear View Mirror Interior Rear View Mirror. TEST the system for normal operation.
No
REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection to diagnose the Local Interconnect Network (LIN) concern.
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H18 CHECK FOR VOLTAGE TO THE INTERIOR AUTO-DIMMING MIRROR REVERSE CIRCUIT
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C9039.
- Ignition ON.
- Select REVERSE.
- Measure the voltage between interior rear view mirror C9039-9, circuit CLS28 (BU/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new interior rear view mirror. REFER to Interior Rear View Mirror Interior Rear View Mirror. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
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