Retained Accessory Power

[blittle]

I have a 2008 2500hd duramax crew cab. I was having problems with the left front door lock not working all of the time so I took it in the the local dealer for diagnosis. When I got the truck back the radio goes off when the truck ignition is turned off. The dome light comes on as before and the windows still work as before but it's just the radio that doesn't continue to work. Now the dealer wants we to bring it back in for another diagnosis. Any suggestions for this problem? Thanks

[gmtech4]

Retained Accessory Power Description and
Operation

Retained Accessory Power
(RAP)

The retained accessory power (RAP) system allows specific vehicle functions
to operate for a specific amount of time after the ignition switch is turned
OFF. The BCM monitors the ignition switch position, battery condition, and each
door open/closed status to determine whether RAP should be initiated or
terminated. RAP is controlled with 2 different methods; serial data and relay
control. The relay is internal to the BCM and feeds multiple external
components. Some modules receive a RAP message over the serial data circuits.
Serial data controlled RAP is deactivated as required by their modules RAP power
mode operation. Other subsystems are activated directly by the BCM through the
internal RAP relay. Components and systems that are active in RAP are also
activated anytime the ignition is any position other than OFF regardless of the
door switch signals.

The BCM sends a serial data power mode message ending the RAP function when
one of the following conditions are met:

• The BCM receives an input indicating the opening of any passenger
  compartment door after the ignition key is out of the ignition.
  
  
  

  Important: The only door that will turn off the radio during RAP is
  the driver door. This is a function of the radio and will still turn off after
  the time limit.

• The BCM internal timer for RAP expires after approximately 10 minutes.
• The BCM detects a decrease in battery voltage below a calibrated limit.

Relay Control of Retained Accessory
Power (RAP)

The body control module (BCM) keeps the internal RAP relay energized during
all power modes, except Off-Awake and Crank. The relay is also energized for
approximately 10 minutes after shutting the ignition OFF and removing the key,
providing no door is opened. The BCM will de-energize the internal RAP relay at
the same time the serial data message is sent to end RAP. When the internal RAP
relay is energized voltage is applied on the accessory voltage circuit at BCM
harness connector X2 terminal 22.

The devices powered by the internal RAP relay during the RAP power mode are
as follows:

• Sunroof module - (CF5)
• 
  
• Mobile radio fuse block, relay A - (9L4)
• 
  
• Sliding rear window switch - (A48)
• 
  
• Window switches, driver and passenger - (A31 w/o AN3)

Serial Data Control of Retained
Accessory Power (RAP)

RAP systems controlled by serial data are as follows:

Power Windows

If equipped with RPO AN3 the front window switches are separate modules that
operate the windows on their respective side of the vehicle and receive the
serial data RAP messages. Window RAP activation/termination timing is the same
as relay operation.

 

Vehicle Communication Interface Module (VCIM) (Onstar®)

VCIM RAP activation/termination is the same as radio operation with 1
exception; if there is an active call when the ignition key is turned off the
VCIM will remain in RAP mode and keep the radio in RAP mode until the call is
terminated.

 

Radio

Radio RAP activation/termination is the same as relay operation with 1
exception; the only door switch that will turn off the radio during RAP is the
driver door open switch.

 

[Doonatic]

On ‎8‎/‎18‎/‎2013 at 6:33 PM, gmtech4 said:

Retained Accessory Power Description and
Operation

 

 

Retained Accessory Power
(RAP)
 

The retained accessory power (RAP) system allows specific vehicle functions
to operate for a specific amount of time after the ignition switch is turned
OFF. The BCM monitors the ignition switch position, battery condition, and each
door open/closed status to determine whether RAP should be initiated or
terminated. RAP is controlled with 2 different methods; serial data and relay
control. The relay is internal to the BCM and feeds multiple external
components. Some modules receive a RAP message over the serial data circuits.
Serial data controlled RAP is deactivated as required by their modules RAP power
mode operation. Other subsystems are activated directly by the BCM through the
internal RAP relay. Components and systems that are active in RAP are also
activated anytime the ignition is any position other than OFF regardless of the
door switch signals.

 

The BCM sends a serial data power mode message ending the RAP function when
one of the following conditions are met:

•  
• The BCM receives an input indicating the opening of any passenger
  compartment door after the ignition key is out of the ignition.
   

  Important: The only door that will turn off the radio during RAP is
  the driver door. This is a function of the radio and will still turn off after
  the time limit.

•  
• The BCM internal timer for RAP expires after approximately 10 minutes.
•  
• The BCM detects a decrease in battery voltage below a calibrated limit.

Relay Control of Retained Accessory
Power (RAP)
 

The body control module (BCM) keeps the internal RAP relay energized during
all power modes, except Off-Awake and Crank. The relay is also energized for
approximately 10 minutes after shutting the ignition OFF and removing the key,
providing no door is opened. The BCM will de-energize the internal RAP relay at
the same time the serial data message is sent to end RAP. When the internal RAP
relay is energized voltage is applied on the accessory voltage circuit at BCM
harness connector X2 terminal 22.

 

The devices powered by the internal RAP relay during the RAP power mode are
as follows:

•  
• Sunroof module - (CF5)
•  
• Mobile radio fuse block, relay A - (9L4)
•  
• Sliding rear window switch - (A48)
•  
• Window switches, driver and passenger - (A31 w/o AN3)

 

Serial Data Control of Retained
Accessory Power (RAP)
 

RAP systems controlled by serial data are as follows:

 

Power Windows

 

If equipped with RPO AN3 the front window switches are separate modules that
operate the windows on their respective side of the vehicle and receive the
serial data RAP messages. Window RAP activation/termination timing is the same
as relay operation.

 

 

 

Vehicle Communication Interface Module (VCIM) (Onstar®)

 

VCIM RAP activation/termination is the same as radio operation with 1
exception; if there is an active call when the ignition key is turned off the
VCIM will remain in RAP mode and keep the radio in RAP mode until the call is
terminated.

 

 

 

Radio

 

Radio RAP activation/termination is the same as relay operation with 1
exception; the only door switch that will turn off the radio during RAP is the
driver door open switch.

 

 

so how then, do you reset RAP, without going to the dealer, and being charged an arm and a leg?

[gmtech4]

Ya don’t reset it , it’s in the programming 

[Doonatic]

On 7/6/2018 at 5:01 AM, gmtech4 said:

Ya don’t reset it , it’s in the programming 

Rob,

 

sorry it has been a minute since you last posted on this. So if RAP cant be reset, can the BCM be reprogrammed or something, to “reboot” RAP?  Honestly, I am starting to think that the problem I am having with RAP, is with the radio harness itself, since all the other options work as they are supposed to.

[tigers2007]

It’s either the door switch built into the latch assembly or **most likely** the door wiring harness. It takes about 45 min to replace. Expect a lead time of 3-weeks to get the harness directly from GM. It is about $90. I just replaced both driver door harness assemblies in my ‘09 Silverado AND Tahoe and BOTH vehicles gremlins went away. I was having issues with intermittent RAP, dome light, power mirror control, power window not going up blah blah.

[*racer_x]

Hey, 2005 Silverado, 5.3l, the repair shop I use when Im too busy said, my truck throws a stereo code, When I turn the ignition switch on, I have no stereo, electric windows etc.. Nothing works until you crank the engine. The previous owner spent piles of money at the dealer for this issue. No results of course. Im not into throwing parts at something, especially at $135.00 an hr. There has to be a way to diagnose this issue. Any suggestions would be appreciated..