Reading and Clearing Diagnostic Trouble Codes
ENTERING DIAGNOSTICS1. In order to enter diagnostics the Body Control Module (BCM) PRGRM Fuse must be pulled.
2. Turn the Ignition Switch to "ACCESSORY."
3. The Seat Belt Indicator and the Chime will activate (flash and chime) 2-4 times indicating which type of BCM is in the vehicle. Check that the BCM in the vehicle is compatible with all of the features on the vehicle. If not place the proper BCM in the vehicle.
^ At this point the vehicle is in the Feature Customization Mode and the Interior Lighting, Automatic Door Lock, Last Door Closed and Lockout Deterrent, Remote Drivers Door Unlock Control, Remote Lock and Unlock Confirmation, Remote Activation Verification, Content Theft Deterrent/Shock Sensor Control, and the Content Theft Deterrent Arming and Disarming can be customized. Refer to appropriate customizing procedures. Lighting and Horns Locks Antitheft and Alarm Systems
4. Turn the Ignition Switch to the "LOCK" position and then to "ACCESSORY" within 1 second.
5. The Diagnostic Codes (DTCs) may flash and chime simultaneously from 1 to 8 times equalling that Diagnostic trouble code.
^ Diagnostic trouble codes will be stored for 10 years unless erased.
^ If there are codes in memory record them and then erase the codes. To erase the codes press and hold any Door "UNLOCK" switch for 4 seconds.
^ Exit diagnostics.
^ With the codes that have been recorded test there functionality.
^ Renter diagnostics and see if these codes exist. If they do see symptom table for appropriate DTC code.
6. If there is more than one trouble code in memory the codes will be flashed in sequence pausing for 2 seconds between each code. These codes will repeat 3 times.
7. Open and close any door. You should hear a chime if you are in the diagnostic mode. If a chime is not heard, try to renter diagnostics by starting this procedure over with step #1. If diagnostics have not been entered after a second attempt, refer to the symptom table for "Cannot Enter Diagnostics, Chart #9."
DIAGNOSTIC TROUBLE CODES
The following is a list of Diagnostic codes (refer to symptom table for diagnosis):
^ Code I Seat Belt Indicator.
^ Code 2 Protected Battery Feed to Courtesy Lamps.
^ Code 3 Courtesy Lamps.
^ Code 6 Park Lamps (Theft Deterrent).
^ Code 7 Horn (Theft Deterrent).
^ Code 8 Remote Keyless Entry.
INPUT/OUTPUT DIAGNOSTICS
After all diagnostic codes have been displayed the MALL subsystem provides individual input and output diagnostic checks for all functions. For example, if the Driver Door is opened and then closed the system provides feedback of a single flash and bong for the opening operation and a single flash and bong for the closing operation of the door. If this does not occur then there is an open or short in that circuit or a bad component. This is also a good test for the RKE Transmitter. While in Diagnostics when any button is pressed on the RKE Transmitter a chime will be heard indicating the RCDLR received a signal from the RKE Transmitter and transferred that signal to the BCM. The interior lamps can also be tested in Diagnostics. The interior lamps are connected in parallel and when they are all in the off position, and when one of the lamps is turned on a chime will be heard. The tamper signal can also be tested in Diagnostics. To further test the Interior Lamps and the Tamper signal and additional outputs, the BCM goes through the following cycle starting at cycle #1 by turning the Headlamp and I/P Lamp Dimmer Switch from an OFF to an ON position:
1. Deactivate the Battery output to the Courtesy Lamps.
2. Activates the Battery output to the Courtesy Lamps.
3. If the mileage flag is set the Courtesy output is inactive them activates the Courtesy output for 1 second. The Interior Lamps will change state when this occurs.
4. Activates the Park Lamps for 1 second.
5. Activates the Horn for 1/2 a second.
6. Enables Shock Sensor diagnostics and turns the Security Indicator Lamp "ON."
7. Disables Shock Sensor diagnostics and turns the Security Indicator Lamp "OFF."
Each time the Headlamp and I/P Lamp Dimmer Switch goes from off to on, the BCM goes to the next cycle and the chime will bong letting the technician know what cycle the BCM is at. BCM types 2, and 3 cycle through the table repeating at cycle #1 after cycle #3. BCM type 4 cycles through the table at cycle #1 after cycle #7.
SHOCK SENSOR DIAGNOSTICS
If Shock Sensor Diagnostics is enabled (cycle #6 in the list above), MALL subsystem type 4 will activate the HORN output for a period of 25ms upon detection of an inactive to active transition on the TAMPER input. MALL subsystem type 4 will activate the HORN output for a period of 100ms upon detection of an inactive to active transition on the TAMPER input. The technician will be able to test the Tamper input anywhere on the vehicle while in this cycle.
EXITING DIAGNOSTICS
Once initiated, the MALL subsystem will remain in the diagnostics mode until one or more of the following conditions is met:
1. Take the Ignition Switch out of the "ACCESSORY" position.
2. Turn the Ignition Switch to the "RUN" position.
3. Place the BCM PRGRM Fuse back into the Fuse Block.