Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- An inaccurate temperature display indicates an abnormal resistance condition within the system.
- For intermittent diagnosis, refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS .
The following table will be used to measure the resistance of the sensor and compare it with the actual ambient temperature. The mirror's temperature accuracy should be within 5 degrees of the actual temperature. The actual temperature should not be taken from a radio station, a sign displaying the temperature, etc. A temperature measuring tool such as a thermometer should be used. Some temperature measuring tools may be within 5 degrees of the actual temperature. Make sure to consult the manufacturer for the accuracy of the tool. This comparison can make the mirror seem off by 5-10 degrees of the actual temperature when it is not.
Ambient Air Temperature Sensor Resistance
| °C | °F | Minimum Resistance K Ohms |
Maximum Resistance K Ohms |
|---|---|---|---|
| -35 | -31 | 234.81 | 250.59 |
| -30 | -22 | 171.69 | 182.31 |
| -25 | -13 | 126.82 | 133.99 |
| -20 | -4 | 94.63 | 99.49 |
| -15 | 5 | 71.30 | 74.58 |
| -10 | 14 | 54.21 | 56.43 |
| -5 | 23 | 41.48 | 43.17 |
| 0 | 32 | 32.00 | 33.31 |
| 5 | 41 | 24.96 | 25.83 |
| 10 | 50 | 19.61 | 20.19 |
| 15 | 59 | 15.49 | 15.94 |
| 20 | 68 | 12.31 | 12.67 |
| 25 | 77 | 9.85 | 10.12 |
| 30 | 86 | 7.96 | 8.15 |
| 35 | 95 | 6.45 | 6.61 |
| 40 | 104 | 5.27 | 5.39 |
| 45 | 113 | 4.32 | 4.42 |
| 50 | 122 | 3.56 | 3.64 |
| 55 | 131 | 2.95 | 3.02 |
| 60 | 140 | 2.46 | 2.52 |
Mirrors - Temperature Display Inaccurate
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Inside Rearview Mirror Schematics Connector End View Reference: Stationary Windows Connector End Views |
|||
| 1 | Did you review the Automatic Day-Night Mirror Description and Operation? | Go to Step 2 | Go to Inside Rearview Mirror Description and Operation |
| 2 |
IMPORTANT:
Verify the J 33431-C
resistance settings with a DMM.
Disconnect one of the J 33431-C leads momentarily between the resistance settings in order to quickly update the temperature display. |
Go to Step 5 | Go to Step 3 |
| 3 | Test the signal circuit of the ambient temperature sensor for a high resistance. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 4 |
| 4 | Test the ground circuit of the ambient temperature sensor for a high resistance. Refer to CIRCUIT TESTING
and WIRING REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 6 |
| 5 | Inspect for poor connections at the harness connector of the ambient temperature sensor. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 7 |
| 6 | Inspect for poor connections at the harness connector of the inside rearview mirror. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
and CONNECTOR REPAIRS
. Did you find and correct the condition? |
Go to Step 9 | Go to Step 8 |
| 7 | Replace the ambient temperature sensor. Refer to Ambient Air Temperature Sensor Replacement . Did you complete the replacement? |
Go to Step 9 | - |
| 8 | Replace the inside rearview mirror. Refer to Rearview Mirror Replacement . Did you complete the replacement? |
Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |