Body Control Modules - Old Style: Other GMC Yukon Denali

ASLEEP & AWAKE FUNCTIONS

After ignition switch is turned off and 20 minutes elapse without any wake up signals, Body Control Module (BCM) enters an asleep state and goes into low power mode. Wake up signals turn BCM on to begin controlling and/or monitoring of certain functions. BCM wake-up inputs are as follows

1. Dome light.
2. Door ajar switches.
3. Door handle switches.
4. Ignition key put into ignition switch.
5. Ignition key removed from ignition switch.
6. Interior light request active.
7. Ignition turned on.
8. Key in door lock switch.
9. Liftgate jamb switch
10. Liftgate release switch.
11. Parking lights.
12. Power door lock switches.
13. Remote transmitter request to BCM.

AUDIBLE WARNINGS (CHIME)

When BCM determines a driver warning chime is needed, BCM will sound chime when applicable.

BATTERY RUNDOWN PROTECTION

BCM helps to prevent inadvertent battery rundown from situations such as courtesy lights left on. BCM will turn off courtesy light circuit after ignition has been off for 20 minutes and no light request input has been received.

DOOR LOCK/UNLOCK SWITCH FUNCTION

Driver's and passenger's door lock/unlock switches are inputs to BCM. BCM will command door lock relay to unlock driver's door according to state of driver's or passenger's door lock switch.

DRIVER WARNING TELLTALES

BCM activates seat belt telltale in instrument cluster.

EXIT LIGHTING

Interior lights will illuminate for 40 seconds when ignition key is removed from ignition switch.

ILLUMINATED ENTRY

Interior lights will illuminate for 15 seconds when any door is opened and closed.

INTERIOR ILLUMINATION

Discrete input to BCM from door jamb switches or door handle or dome light inputs provide control for courtesy lights, illuminated entry control of courtesy lights, vanity mirror light, dome lights, glove box lights and reading lights. BCM can turn on some of interior lighting independently of interior lighting system.

LIFTGATE RELEASE FUNCTION

Liftgate release switch is an input to BCM. If liftgate release switch is pressed, BCM will energize liftgate release relay and command liftgate to release if shift lever is in Park or Neutral or parking brake conditions are met.

LOCKOUT PREVENTION

Lockout prevention feature is activated when key is in ignition switch, any door is opened and power door lock is pressed. This feature will lock all doors, then unlock driver's door.

POWER DOOR LOCK/UNLOCK FUNCTION

BCM is responsible for energizing door lock relay. Door lock relay will be energized whenever BCM receives a command from any door lock/unlock switch or remote transmitter.

REMOTE ILLUMINATED ENTRY

Interior lights will illuminate for 40 seconds when unlock button or liftgate release button is pressed on transmitter. Interior lights will illuminate for 2 seconds when lock button is pressed on transmitter.

RETAINED ACCESSORY POWER

Retained Accessory Power (RAP) feature allows power windows, radio and front and rear wiper systems to be operated after ignition is turned from on to off. Power will be turned off when any door is opened or 10 minutes has elapsed.

REMOTE KEYLESS ENTRY (RKE) TRANSMITTER

Note. Programming of RKE transmitters can not be done simultaneously. First RKE transmitter must be programmed completely before programming next RKE transmitter(s). A maximum of 4 RKE transmitters may be programmed into BCM memory.

1. Turn ignition switch to RUN position to deactivate Content Theft Deterrent (CTD) alarm system (if equipped). Turn ignition switch to OFF position. Remove RADIO fuse (25-amp) from instrument panel fuse block.
2. Cycle ignition switch from OFF to RUN position 3 times within 5 seconds, leaving ignition switch in ON position. Body Control Module (BCM) will indicate programming sequence is active by activating hatch release, locking doors, then unlocking doors.
3. Press and hold both LOCK and UNLOCK buttons on RKE transmitter to be programmed for 15 seconds. Doors will lock and unlock, and hatch release will activate to verify RKE transmitter has been recognized by BCM.
4. Repeat step 3 for remaining RKE transmitters. After programming RKE transmitter(s), reinstall RADIO fuse. Turn ignition switch to OFF position.

RAP Inoperative

1. Use DVOM connected to ground, backprobe Black 6-pin BCM connector C2 terminal "F" (Red wire). See «COMPONENT LOCATIONS»(ref-9118-S38165319662000100500000). see scheme 3 If battery voltage exists, go to step 3. If battery voltage does not exist, go to next step.
2. Check for open or poor connection in Red wire between Black 6-pin BCM connector C2 terminal "F" and IGNB fuse (50-amp) located in underhood fuse block. See «WIRING DIAGRAMS»(ref-9118-S12419734192000100500000). Repair as necessary and retest operation.
3. Gain access to Blue 56-pin in-line harness connector, located under floor console trim plate. Turn ignition switch to RUN position, then to OFF position (RAP mode). Ensure doors stay closed so as not to exit RAP mode. Using DVOM connected to ground, backprobe Blue 56-pin in-line harness connector terminal B9 (Dark Blue wire). (Scheme 13) If battery voltage exists, go to next step. If battery voltage does not exist, go to step 5.
4. Using DVOM connected to ground, backprobe RR WIPER fuse located in instrument panel fuse block. If battery voltage exists, system is okay at this time. If battery voltage does not exist, go to step 7.
5. Using DVOM connected to ground, backprobe Black 6-pin BCM connector C2 terminal "C" (Dark Blue wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step 8.
6. Repair open in Dark Blue wire between Black 6-pin BCM connector C2 terminal "C" and Blue 56-pin in-line harness connector terminal B9. See «WIRING DIAGRAMS»(ref-9118-S12419734192000100500000). Retest operation.
7. Repair open in Dark Blue wire between Blue 56-pin in-line harness connector terminal B9 and CTSY fuse. See «WIRING DIAGRAMS»(ref-9118-S12419734192000100500000). Retest operation.
8. Replace Body Control Module (BCM). See «BODY CONTROL MODULE (BCM)»(ref-9118-S29455002022000100500000) under REMOVAL & INSTALLATION. Retest operation.

RAP Inactive

1. Gain access to Blue 56-pin in-line harness connector, located under floor console trim plate. Disconnect Blue 56-pin in-line harness connector. Using DVOM connected to ground, backprobe console-side of Blue 56-pin in-line harness connector terminal B9. (Scheme 13) If battery voltage exists, go to next step. If battery voltage does not exist, go to step 3.
2. Check for short to voltage in Dark Blue wire between Black 6-pin BCM connector C2 terminal "C" and Blue 56-pin in-line harness connector terminal B9. see scheme 3 See «WIRING DIAGRAMS»(ref-9118-S12419734192000100500000). Repair as necessary and retest operation. If Dark Blue wire checks okay, go to step 5.
3. Using DVOM connected to ground, backprobe instrument panel-side of Blue 56-pin in-line harness connector terminal B9. If battery voltage exists, go to next step. If battery voltage does not exist, system is okay at this time.
4. Repair short to battery voltage in Dark Blue wire between Blue 56-pin in-line harness connector terminal B9 and instrument panel fuse block. See «WIRING DIAGRAMS»(ref-9118-S12419734192000100500000). Retest operation.
5. Replace Body Control Module (BCM). See «BODY CONTROL MODULE (BCM)»(ref-9118-S29455002022000100500000) under REMOVAL & INSTALLATION. Retest operation.

Scheme 13

BODY CONTROL MODULE (BCM)

Note. It is necessary to remove one front seat during Body Control Module (BCM) replacement. Either seat can be removed.