| Diagnosis and Testing Refer to Wiring Diagrams Section 501-14B, for schematic and connector information. Special Tool(s) | | Digital Volt Ohm Meter 105R0051 | Principles of Operation Keyless Entry When a remote transmitter button is depressed, it transmits the appropriate command to the central security module (CSM) as a radio frequency. The CSM receives the command from the remote transmitter through an antenna, that is incorporated into the harness connected to the CSM through CSM C451a. When the CSM receives a command from a remote transmitter, it then sends the appropriate output to control the desired devices. These output devices include: - The driver and passenger door lock units.
- The central timer module (CTM).
- The right and left flasher relays.
- The liftgate release motor.
The CSM sends a signal to the CTM when courtesy lamp illumination is required. The CSM is equipped with an erasable programmable read-only memory (EPROM) chip. This EPROM stores the transmitter identification codes (TICs) for any transmitters that have been programmed to that vehicle. The codes are stored in a non-volatile memory, protecting them from power loss. Such a power loss could occur if the vehicle battery has to be disconnected for vehicle repair, or if the battery were allowed to discharge. Inspection and Verification NOTE:Make sure the battery is fully charged before starting electrical diagnosis. NOTE:Prior to carrying out the CSM self-test make sure that both the driver and passenger doors are open. - Verify the customer concern by operating the system.
- Visually inspect for obvious signs of mechanical or electrical damage.
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the NGS tester still does not power up, refer to the New Generation STAR tester manual.
- Carry out the DATA LINK DIAGNOSTIC TEST. If the NGS tester responds with:
- CKT914, CKT915, or CKT70- ALL ECUS NO RESP/NOT EQUIP, refer to Section 418-00.
- NO RESP/NOT EQUIP for Central Security Module (CSM). GO to Pinpoint Test E.
- System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the Central Security Module.
- If the DTCs retrieved are related to the concern, go to Central Security Module Diagnostic Trouble Code (DTC) Index.
- If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics.
Visual Inspection Chart | Mechanical | Electrical | - Binding lock mechanisms
- Binding linkage
- Misaligned door
| - Vehicle battery
- Remote transmitter batteries
- Fuse(s) 22 (40A), 25 (20A), 30 (7.5A)
- Wiring harness
- Loose or corroded connector(s)
- Circuit(s)
- Door lock switch
- Power door lock actuator
| Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | The doors do not lock/unlock using the remote transmitter | * Circuit. * Remote transmitter batteries. * Central security module. (CSM) * Remote transmitter. * CSM antenna. | * GO to Pinpoint Test A. | | The liftgate is inoperative using the remote transmitter | * Circuit. * Liftgate motor. * Remote transmitter. * CSM. | * GO to Pinpoint Test B. | | A single door lock is inoperative - driver door does not unlock using the remote transmitter | * Circuit. * Power door lock actuator. * CSM. | * GO to Pinpoint Test C. | | The doors do not lock/unlock using the remote transmitters - passenger door | * Circuit. * Power door lock actuator. * CSM. | * GO to Pinpoint Test D. | | Panic feature does not operate correctly - remote transmitter | * Circuit . * CSM. * Remote transmitter. * Remote transmitter batteries. | * GO to Pinpoint Test E. | Pinpoint Tests | PINPOINT TEST A : THE DOORS DO NOT LOCK/UNLOCK USING THE REMOTE TRANSMITTER | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: CHECK THE DOOR LOCK SWITCHES FOR CORRECT OPERATION | | | 1 Lock the doors using the driver and passenger door lock switches. | | | 2 Unlock the doors using the driver and passenger door lock switches. | | | Do the doors lock and unlock correctly? Yes No | | A2: CHECK CSM ANTENNA FOR SHORT TO GROUND | | | 1 Disconnect CSM Antenna. | | | 2 Inspect the remote entry antenna and C451a pin 9, harness side for damage. | | | Are the antenna and antenna connector OK? Yes CONNECT the remote entry antenna GO to A3. No INSTALL a new antenna. TEST the system for normal operation. | | A3: PROGRAM REMOTE TRANSMITTER | | | 1 | | | Does the remote entry function operate? Yes No | | PINPOINT TEST C : A SINGLE DOOR LOCK IS INOPERATIVE - DRIVER DOOR DOES NOT UNLOCK USING REMOTE TRANSMITTER | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK DRIVER DOOR LOCK SWITCH FOR CORRECT OPERATION | | | 1 Lock the doors. | | | 2 Unlock the doors using the driver door lock switch. | | | Does the driver door unlock when the switch is pressed? Yes No | | PINPOINT TEST D : A SINGLE DOOR LOCK IS INOPERATIVE - PASSENGER DOOR DOES NOT UNLOCK USING REMOTE TRANSMITTER | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | D1: CHECK PASSENGER DOOR LOCK SWITCH FOR CORRECT OPERATION | | | 1 Lock the doors. | | | 2 Unlock the doors using the passenger door lock switch. | | | Does the passenger door unlock when the switch is pressed? Yes No | |
