Circuit Description
The LH Door Control Module (LDCM) provides an illuminated output control for the LH door switch assembly. This allows the LDCM to illuminate the LH door switch back lighting, memory indicators, and mirror select indicators. The LDCM provides a single power supply for all illuminated light functions. The LDCM uses a Pulse-Width Modulation (PWM) ground output to control the dimming level to the LH door switch back lighting lamp. When the LDCM receives a message on the serial data line, indicating that the park lamps or headlamps are ON, the LDCM will control the LH switch illumination by PWM-ing the ground. The LDCM also provides a ground output for the memory 1, memory 2, LH and RH mirror select switch indicators. The LDCM provides a ground output to each of these indicators allowing the LDCM to illuminate the applicable indicator based upon the select switch signal information. The LDCM monitors the amount of current draw on all of the illumination lamp control circuits. If the current draw is not within the acceptable range, a malfunction is present and a DTC will set.
The RH Door Control Module (RDCM) provides an illuminated LED output control for the RH door switch assembly. This output control allows the RDCM to illuminate the switch assembly when the park lamps and/or headlamps are ON. The RDCM provides power and a Pulse-Width Modulation (PWM) ground output to the RH door switch. When the RDCM receives a message on the serial data line indicating that the park lamps or headlamps are ON, the RDCM will control the RH switch illumination by PWM-ing the ground. The RDCM monitors the amount of current draw on the illumination lamp control circuit. If the current draw is not within the acceptable range, a malfunction is present and a DTC will set.
Conditions for Setting the DTC
| • | A DCM detects a high current (short to ground) condition in any one of the following door switch control circuits: |
| - | RH or LH mirror indicator |
| - | Memory 1 indicator |
| - | Memory 2 indicator |
| - | RH or LH door switch Illumination lamp |
| • | Condition must be present for 20 ms. |
Action Taken When the DTC Sets
| • | Stores a history DTC B2278 or B2279 in a DCM memory. |
| • | The appropriate DCM will disable the malfunctioning indicator. |
| • | These DTCs can only be set as a history code even if the malfunction is current. |
| • | No driver warning message will be displayed for this DTC. |
Conditions for Clearing the DTC
| • | The DCM no longer detects a high current (short to ground) condition in the applicable indicator/lamp control circuit for longer than 20 ms. |
| • | Use the IPC clearing DTCs feature. |
| • | Use a scan tool. |
Diagnostic Aids
| • | The following conditions may cause an intermittent malfunction: |
| - | There is an intermittent short to voltage or ground in the following door switch illumination or indicator control circuits: |
| • | RH or LH door switch illumination lamp |
| • | Memory 1 select indicator |
| • | Memory 2 select indicator |
| • | LH mirror select indicator |
| • | RH mirror select indicator |
| - | The RH or LH door switch indicator/lamp is shorted. |
| • | If the DTC does not reset after the code is cleared, then the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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This tests if a door switch for an internal short to voltage or ground.
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This tests a door switch illumination circuits for a short to voltage or ground.
Step | Action | Value(s) | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Power Door Systems Diagnostic System Check? | -- | Go to Step 2 | |||||||||||
Does the DTC reset? | -- | Go to Step 3 | Go to Step 5 | |||||||||||
Test the following appropriate door switch illumination control circuits, if they apply, for a short to ground or voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition? | -- | Go to Step 6 | Go to Step 4 | |||||||||||
4 | Replace the appropriate DCM. Refer to Door Control Module Replacement . Did you complete the replacement? | -- | Go to Step 6 | -- | ||||||||||
5 | Replace the appropriate door switch. Refer to Front Door Switch Replacement . Did you complete the replacement? | -- | Go to Step 6 | -- | ||||||||||
6 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
