Help! Error code NOT FOUND on the C5 list!

[XLR8]

Im having a problem with my battery holding a full charge. When I cleared all history codes (I did write them down first), the 2 codes that remain current is an 99HVAC code: B0441H and A6SCM code: B2860H/C. The battery drains very fast (minutes) when the key is off (even with a new battery). I've changed the alternator and still getting the same results. The list provided here does not list the SCM code. Any ides on what could cause a battery to go from a 13 volt reading to 5.5 so quickly? When started it fluctuates slightly between 13 & 13.7

I'm posting this in its own thread so that it gets the attention it needs! Anyone have ideas or suggestions to help this member?

Jane Ann

 

[minifridge1138]

It sounds like you have a short.
With the key in "off" there should not be any noticeable drain on the battery.
If something is still on, that would drain the battery.
I would turn the car off, and then go around with a volt meter checking wiring harnesses to see if anything had 12V.

That is an odd problem.
Good Luck!

 

[zagger]

Do you have an aftermarket sound system, maybe an amp? Lots of time these can cause high drain on the battery since they usually are wired directly to it and they rely on a signal from the radio to switch them.

 

[zagger]

The B2860 according to my list is a telescopic position sensor failure code. Have you had problems starting the car, having to take the key in and out several times before starting? If so it could also be the shifter position sensor shorting out. Good luck, regards Zig.

 

[c4c5specialist]

HI there,
What year is the car??
What aftermarket equipment is on it?
Allthebest, c4c5

 

[roxeye1]

It's a 2000. No after market stuff at all - I also get a loud buzz, when trying to recharge the battery (with a trickle charger), from the head lamp motor and the cd changer tries to shuffle continuously without stopping. This continues until I pull the HDLP MOTOR (L,R) fuses and disconect the cd changer. Even after doing this, the battery drains. I assume this aberrant action is occuring due to low voltage??

 

[roxeye1]

I have recieved a recall notice concerning a shifter/lock issue for the 2K MY. I have not, however, had it serviced for this noticed. Not familiar with what this issue could cause. I have not had any problems starting the car for any other apparent reason than the battery voltage is too low to start the car

 

[Eric Reeves]

Here is what I can tell you. Both of the Bxxxx codes refer to the body control module. The B0441H code is HVAC related as you know. It indicates a left actuator out of range. The B2860 code is a telescoping column position failure. The A codes usually refer to accessories in this case A6SCM being a seat control module but I do not know which one. All of the codes that have an "H" in them are history meaning that they happened in the past and may be a one time event but the code was stored. I recommend that you clear your codes out on the DIC and see where that gets you. I have had codes stored in there before that I never knew existed until I looked. Cleared them and they have not returned. I chalk that up to the eletronic gremlins.

 

[zagger]

The 99HVAC & B0441H code could be just a byproduct of the battery going dead. Clearing the codes (write them down first) is always a good idea as it lets you know what is happening at present time. As to the question about the starting, I came across a shorted shifter position sensor that had a similar affect in draining the battery and throwing the codes. I any case there is a strong short somewhere to cause such a drain on the battery. I'll try to dig deeper into my notes to see if I can find anything similar. One thing I have not asked is how old is your battery and what type (lead/acid, sealed, gel). It might be a good idea to test it , you can get it done for free at Kregan or similar auto part store.

 

[c4c5specialist]

HI there,
The drain is the major key here.
You need to perform a draw test to determine what is causing the dead battery.
Both codes could occur with a battery that has a low reserve voltage.
That being said, using a draw test would be the NEXT course of action, once your battery is CONFIRMED to be good.
Allthebest, c4c5

 

[nitroused]

It's a 2000. No after market stuff at all - I also get a loud buzz, when trying to recharge the battery (with a trickle charger), from the head lamp motor and the cd changer tries to shuffle continuously without stopping. This continues until I pull the HDLP MOTOR (L,R) fuses and disconect the cd changer. Even after doing this, the battery drains. I assume this aberrant action is occuring due to low voltage??

let me know if you fixed your issue and what fixed it cause i have the same identical problem in mine ,i've done 2 draw test with flukes and the biggest drop comes from the radio fuse,but not sure if that's it cause even without that fuse in place the battery still dies in 1 day or so,i don't want to put aftermarket crap and still have the same issue and i like the way the factory system sounds,any help?

 

[Greg_E]

I just noticed that this thread is about 7 months old, so I assume the person requesting help has resolved the problem. Perhaps this will be useful info for others.

Here is some good general information that I came across regarding BCM functions. Pay special attention to the section on the sleep mode function. If something is preventing the BCM from going into sleep mode, it will drain the battery.
Below that is info on how to troubleshoot the problem.
This hard work was done by others, so I'm not taking any credit.

As C4C5Specialist stated, you need to do a draw test with a known good battery.

"Hi, the info below may help you isolate the problem.
SEE Below
++++++++++++++++++++++++++++++++++
Body Control System Description and Operation
This vehicle is equipped with a Body Control Module (BCM) capable of performing multiple body control functions. The BCM, which is the power mode master, is responsible for sending the power mode messages on the serial data line to other systems.

Serial Data Power Mode
On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the Body Control Module (BCM). The PMM receives two signals/circuits from the ignition switch. These are the Ignition 1 and Ignition 2 ignition switch signals/circuits.

To determine the correct power mode the PMM uses:

The state of these signals/circuits, either switch closed (B+ = 1) or switch open (B+ = 0)
The sequence of switch closures received by the PMM
The status of the engine run flag
The chart below indicates the modes detected and transmitted by the PMM:

Correct Ignition Switch Inputs Power Mode Selected/Expected
Engine Run Flag Serial Data
Sampled Ignition Signal State
Power Mode State
Key-In Sense

Ignition 1
Ignition 2

OFF
0
0
0
OFF-AWAKE
NA

RAP
0
0
1-0
RAP
NA

UNLOCK
0
0
0-1
UNLOCK
NA

ACCESSORY
0
0
1
ACCESSORY
NA

RUN
1
1
1
RUN
NA

RUN
0
1
1
RUN
NA

CRANK
0
1
1-0
CRANK
NA


Fail-safe Operation
Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the PMM fail to send a power mode message. The fail-safe plan covers those modules using exclusively serial data control of power mode as well as those modules with discrete ignition signal inputs.

Serial Data Messages
The modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid PMM message until they can check for the engine run flag status on the serial data circuits. If the PMM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is True, indicating that the engine is running, the modules fail-safe to "RUN". In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is False, indicating that the engine is not running, the modules fail-safe to "OFF-AWAKE". In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

On this vehicle the following modules receive Serial Data Messages for power mode status:

Driver Door Module (DDM)
Passenger Door Module (PDM)
Radio
Discrete Ignition Signals
Those modules that have discrete ignition signal inputs also remain in the state dictated by the last valid PMM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, B+, the modules will fail-safe to the "RUN" power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to "OFF-AWAKE". In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

BCM Wake-up/Sleep States
The BCM is able to control or perform all of the BCM functions in the wake-up state. The BCM enters the sleep state when active control or monitoring of system functions has stopped, and the BCM has become idle again. The BCM must detect certain wake-up inputs before entering the wake-up state. The BCM monitors for these inputs during the sleep state, where the BCM is able to detect switch transitions that cause the BCM to wake-up when activated or deactivated. Multiple switch inputs are needed in order to sense both the insertion of the ignition key and the power mode requested. This would allow the BCM to enter a sleep state when the key is IN or OUT of the ignition.

The BCM will enter a wake-up state if any of the following wake-up inputs are detected:

Any activity on the serial data line
Hatch ajar switch
Hatch release switch
Door ajar switch
Key-in-ignition switch
Monitored load relay
Park/fog/headlamps are on
The BCM experiences a battery disconnect and reconnect condition.
The ignition is turned ON.
The BCM will enter a sleep state when all of the following conditions exist:

No activity exists on the serial data line.
The ignition switch is OFF.
No outputs are commanded.
No delay timers are actively counting.
No wake-up inputs are present.
If all these conditions are met the BCM will enter a low power or sleep condition. This condition indicates that the BCM, which is the power mode master of the vehicle, has sent an OFF-ASLEEP message to the other systems on the serial data line.

Power Requirements
The BCM has two main power feeds (high and low current), and two main grounds. The low power feed (battery 1) is used to provide power for the BCMs logic and internal driver operation. The high power feed (battery 2) is used to provide power for systems that draw higher amounts of current (motors, lights, etc.). The BCM will operate properly with a system voltage of 9.0-16.0 volts. If system voltages exceed 16.0 volts the BCM will provide protection by disabling certain functions that may be damaged due to higher than normal system voltages.

Monitored Loads
In order to minimize any battery rundown, the BCM can detect if certain electrical loads have been left ON after the ignition is turned OFF and the driver has left the vehicle. When the BCM detects that the ignition has been cycled to the OFF position, the BCM immediately checks the status of the load monitor input. If the BCM detects that a load is present (grounded input), the BCM turns ON the load monitor relay for 15 minutes. If after 15 minutes the BCM still recognizes that a load is present, the BCM will turn OFF the relay, removing the battery voltage from the loads. The BCM continues to monitor this circuit for a switch transition. The BCM will again turn ON the relay for 15 minutes if a switch transition occurs.

Load Shed Control
The BCM can turn off the rear window defogger and heated outside mirror electrical loads when the vehicle is in a condition where these loads may discharge the battery. The BCM will also remove these loads when engine demands are greater.

Interior Lamp Over Voltage Protection
The BCM disables the interior lamp bulbs when the system voltage is above 18.0 volts in order to extend the bulb life.

Driver in Vehicle Detection
Using the ignition switch/door ajar inputs, the BCM can detect whether or not the driver has left the vehicle. If the ignition is turned to OFF with no door ajar status detected, the BCM assumes that the driver is in the vehicle. As soon as the BCM detects a door ajar, the BCM will assume the driver has left the vehicle. The BCM uses this information to determine the RAP status, then sends the status to the other systems also responsible for RAP functions.

BCM Fail-Soft Condition
If a particular BCM malfunction would result in unacceptable system operation, the BCM takes a fail-soft action in order to minimize the condition. A typical fail-soft action would be the substitution of a fixed input or output value when the BCM is unable to interpret data correctly."


Troubleshooting:

"The BCM, RFA and PCM modules are always powered . The BCM has a monitoring program to look for RFA task (Key FOBs) and security stuff. The BCM will power up lights, and preform other power up functions when you open the doors, trunk and hood or open locks OR the trunk at FOB commands.

When you first hook up the amp meter, (IN SERIES) it will read 7-8 amps, then it will start powering down stuff and you will see the current drop off in steps. 6 amps. 2 amps, 1 amp and it will then go into sleep mode where you should see it drop off to 20 - 25 milliamps. That process may take any where from 3 min to 10 min. If you forget to disconnect the hood light, it will take the full 10 min!

Once you have an amp meter, you can insert it in "series" with anything to see what that device is drawing for current.

Here are some of the thing that I have seen in the past that have caused battery drain issues:

Drivers seat EASE ENTRY constantly trying to move the seat. Or the multifunction switch doesn't re-center its self when you position it and the seat is constantly trying to move. The motors are not fused and are on circuit breakers. They will trip and reset as long as the battery has power or until its DEAD!

Head light control module for the pop up head lights. Its on the front frame header below the passengers headlight. Feel it!

If its warm to the touch, its continuously drawing current.

Alternator. Put the meter in series with the field wire. If the diodes are bad, it will draw current when the car is powered down!

Bose processor amplifier under the dash. There is a relay that powers that amp up when the key is on. If the relay sticks on, it will kill the BATT.

Dash lights stay on after you power the car down. Leaving the interior lights on (the round knob below the HUD panel gets turned all the way clock wise!

Had to mention that one.

At the engine fuse center there is a B+ connection. You will see TWO connections there. One wire is the POS battery lead and the other wire goes down to the passengers fuse center. You can place the amp meter in series with the B+ terminal and that wire and see if the excessive current draw is being caused by a curcuit in that fuse center.

You cant do that with the eng comp fuse ctr. If the excessive draw isnt in the pass fuse ctr, it has to be in the eng fuse ctr.

Do a current draw test and report back the results. If you power any load up on the car, you will have to wait the full time required for the BCM to go back to sleep to continue to trouble shoot.

BC "

 

[midyr64]

Having the same problem

When you first hook up the amp meter, (IN SERIES) it will read 7-8 amps, then it will start powering down stuff and you will see the current drop off in steps. 6 amps. 2 amps, 1 amp and it will then go into sleep mode where you should see it drop off to 20 - 25 milliamps. That process may take any where from 3 min to 10 min. If you forget to disconnect the hood light, it will take the full 10 min!

Once you have an amp meter, you can insert it in "series" with anything to see what that device is drawing for current.

Here are some of the thing that I have seen in the past that have caused battery drain issues:

Drivers seat EASE ENTRY constantly trying to move the seat. Or the multifunction switch doesn't re-center its self when you position it and the seat is constantly trying to move. The motors are not fused and are on circuit breakers. They will trip and reset as long as the battery has power or until its DEAD!

Head light control module for the pop up head lights. Its on the front frame header below the passengers headlight. Feel it! If its warm to the touch, its continuously drawing current.

Alternator. Put the meter in series with the field wire. If the diodes are bad, it will draw current when the car is powered down!

Bose processor amplifier under the dash. There is a relay that powers that amp up when the key is on. If the relay sticks on, it will kill the BATT.

Dash lights stay on after you power the car down. Leaving the interior lights on (the round knob below the HUD panel gets turned all the way clock wise! Had to mention that one.

At the engine fuse center there is a B+ connection. You will see TWO connections there. One wire is the POS battery lead and the other wire goes down to the passengers fuse center. You can place the amp meter in series with the B+ terminal and that wire and see if the excessive current draw is being caused by a curcuit in that fuse center. You cant do that with the eng comp fuse ctr. If the excessive draw isnt in the pass fuse ctr, it has to be in the eng fuse ctr.


Do a current draw test and report back the results. If you power any load up on the car, you will have to wait the full time required for the BCM to go back to sleep to continue to trouble shoot.

Greg E

I have been trying to track down my problem with the help of your post, I have a couple of questions what do you mean test in series? I have disconnected my drivers seat power and the battery did not drain overnight so if this is the problem would it be the switch for the power seat causing the problem. I have the Ease Entry off in my settings.

 

[Greg_E]

When you first hook up the amp meter, (IN SERIES) it will read 7-8 amps, then it will start powering down stuff and you will see the current drop off in steps. 6 amps. 2 amps, 1 amp and it will then go into sleep mode where you should see it drop off to 20 - 25 milliamps. That process may take any where from 3 min to 10 min. If you forget to disconnect the hood light, it will take the full 10 min!

Once you have an amp meter, you can insert it in "series" with anything to see what that device is drawing for current.

Here are some of the thing that I have seen in the past that have caused battery drain issues:

Drivers seat EASE ENTRY constantly trying to move the seat. Or the multifunction switch doesn't re-center its self when you position it and the seat is constantly trying to move. The motors are not fused and are on circuit breakers. They will trip and reset as long as the battery has power or until its DEAD!

Head light control module for the pop up head lights. Its on the front frame header below the passengers headlight. Feel it! If its warm to the touch, its continuously drawing current.

Alternator. Put the meter in series with the field wire. If the diodes are bad, it will draw current when the car is powered down!

Bose processor amplifier under the dash. There is a relay that powers that amp up when the key is on. If the relay sticks on, it will kill the BATT.

Dash lights stay on after you power the car down. Leaving the interior lights on (the round knob below the HUD panel gets turned all the way clock wise! Had to mention that one.

At the engine fuse center there is a B+ connection. You will see TWO connections there. One wire is the POS battery lead and the other wire goes down to the passengers fuse center. You can place the amp meter in series with the B+ terminal and that wire and see if the excessive current draw is being caused by a curcuit in that fuse center. You cant do that with the eng comp fuse ctr. If the excessive draw isnt in the pass fuse ctr, it has to be in the eng fuse ctr.


Do a current draw test and report back the results. If you power any load up on the car, you will have to wait the full time required for the BCM to go back to sleep to continue to trouble shoot.

Greg E

I have been trying to track down my problem with the help of your post, I have a couple of questions what do you mean test in series? I have disconnected my drivers seat power and the battery did not drain overnight so if this is the problem would it be the switch for the power seat causing the problem. I have the Ease Entry off in my settings.

First off I'd like to say that the information I posted was originally posted by Bill Curlee. He is the man when it comes to solving electrical problems with C5's. I just reposted what he had stated on one of the other forums in the hopes that it would help someone here.

"Test in series" means that you need to insert the amp meter in the circuit. To check the total current draw you would set your meter to 10amp scale, making sure you have the red meter lead in the "amps" socket on the meter and the black lead in the "common" .
More words of wisdom from Bill:
"Use a DC amp meter capable of reading at least 10 amps and disconnect the NEGATIVE Battery cable. Install the amp meter between the battery cable and the battery terminal. When you first make the connection, you will hear relays click and the headlight motors will sometime operate for a very short period of time. Thats very normal. You may see as high as 8 amps when you first connect it. Then it will systematically drop off to 2 amps, then .5 amps. Once the BCM times out, that will be your finial current draw reading. Usually 10-15 min. If you disconnect the BCM or battery for any reason, or open a door or cause the BCM to come out of sleep mode, this process starts all over again.
Some of the most common things that can cause excessive current draw are:
- Drivers or power passengers seat multifunction switch fails to return to the neutral position and the seat trys to drive into the stops. usually in the rearward position. The air bolster in the seat back can also stay on (if you have that option)
- Drivers seat position feed back pots fail and the MEMORY seat continues to drive to the fully retracted fully lowered position. The seat motors are protected by a thermal fuse and they will trip and reset until the battery dies!! You can UN-PLUG the drivers seat to see if that solves the issue. Just makes sure it's in the correct position for you to drive it."
DO NOT crank the engine with the meter hooked up. You will blow the fuse in the meter if it's a good one, or toast your meter, if it's a cheap one.

It sounds like your on the right track. You really need a manual, so you can properly troubleshoot that circuit. Make sure you don't have a pinched wire to the motor that's shorting to ground. In addition to the causes that Bill has listed, others have found that the motor itself was bad.

 

[midyr64]

I have been trying to track down the battery drain from the drivers seat by unplugging connections from the seat and checking the with an amp meter it looks like when I unplug one of the plugs to a control box (black) under the seat there is no drain. Could anyone tell me what this box does and if it can be replaced.

 

[Greg_E]

It sounds like your talking about the memory seat control module.