Circuit Description
Important: The driver door lock cylinder is connected to the driver door key switch and driver door latch using mechanical linkages. When the driver door lock cylinder is rotated to the UNLOCK position, the driver door is unlocked mechanically. The passenger door lock cylinder is connected to the passenger door key switch and passenger door latch using mechanical linkages. When the passenger door lock cylinder is rotated to the UNLOCK position, the passenger door is unlocked mechanically.
The driver or passenger door key switch signal circuits provide input to the driver door module (DDM) or passenger door module (PDM) when the driver or passenger door lock cylinder is rotated to the UNLOCK position. This input allows the door module to detect a door UNLOCK request. The door module provides power and ground to the door key switch. When the door lock cylinder is rotated to the UNLOCK position, a ground is supplied through the door key switch to the signal circuit, which is pulled low. When the DDM detects low voltage on the driver door key switch signal circuit, it sends a message on the serial data line to the PDM to UNLOCK the passenger door. When the PDM detects low voltage on the passenger door key switch signal circuit, it sends a message on the serial data line to the DDM to UNLOCK the driver door. The messages sent on the serial data line are also used by other systems to execute certain functions. The DDM and PDM monitor the signal circuits to determine how long the ground has been applied. If the DDM or PDM detects that the ground is applied for greater than 20 seconds, a DTC is set.
Conditions for Setting the DTC
| • | The DDM or PDM detects a short to ground on the driver or passenger door key switch signal circuits. |
| • | Condition must be present for greater than 20 seconds. |
Action Taken When the DTC Sets
| • | Stores a history DTC B2252 in DDM memory, or a history DTC B2253 in PDM memory. |
| • | This DTC 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 DDM or PDM no longer detects a short to ground on the driver or passenger door key switch signal circuits for greater than 20 seconds, and:
| • | The DTC is cleared using the IPC clearing feature, or |
| • | The DTC is cleared using a scan tool. |
Diagnostic Aids
Important: The driver door lock cylinder is connected to the driver door key switch in the driver door latch using a mechanical linkage. The passenger door lock cylinder is connected to the passenger door key switch in the passenger door latch using a mechanical linkage. Check to make sure that the mechanical linkages are not disconnected.
| • | The following conditions may cause an intermittent malfunction: |
| - | There is an intermittent short to ground in a door key switch signal circuit. |
| - | A door key switch is shorted to ground internally or is sticking. |
| - | A door key switch was activated for longer than 20 seconds. |
| • | 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 numbers below refer to the step numbers on the diagnostic table.
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Tests for the normal state of the door key switch using a scan tool. The scan tool will display the normal state as Inactive, and Active when the switch is activated.
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Tests if the DDM or PDM is able to detect a change in the door key switch state. The scan tool will display the normal state as Inactive, and Active when the switch is activated.
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Tests for a stuck or shorted door key switch. If a door key switch is stuck or shorted, the state will change from Active to Inactive when the driver or passenger door key switch is disconnected.
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Tests for a short to ground in the door key switch signal circuit.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Door Control Module Schematics Connector End View Reference: Power Door Systems Connector End Views | |||
1 | Did you perform the Door Systems Diagnostic System Check? | Go to Step 2 | |
Does the scan tool display Inactive? | Go to Step 3 | Go to Step 4 | |
Does the Door Key Unlock parameter change state? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 4 | |
Does the scan tool display Inactive? | Go to Step 7 | Go to Step 5 | |
Test the appropriate door key switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 6 | |
6 | Inspect for poor connections at the harness connector of the appropriate door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 8 |
7 | Inspect for poor connections at the C1 harness connector of the appropriate door latch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
8 |
Replace the appropriate door module. Refer to Door Control Module Replacement . Did you complete the replacement? | Go to Step 10 | -- |
9 | Replace the appropriate door latch. Refer to Door Lock Replacement . Did you complete the replacement? | Go to Step 10 | -- |
10 |
Does the DTC reset? | Go to Step 2 | System OK |
