Hey guys. Been gone many years, even having to resort to a new username.

So today I uncovered my 2001 with 12K miles to take it for inspection. It drove fine for about 1/2 a mile and then died at a stop sign. Here is what I observed next.

1. Car tries to start right up but runs rough and has almost no power. I was able to limp it home.
2. No brake lights. When I press the brake the lights on the dash come on regardless of key position.
3. When I turn a blinker on the entire dash blinks.
4. Now the car starts but immediately dies.

Battery is an old red top but but cranks right away. I hate to say this but we did catch a few mice in the garage back in April, I think the car has been started and driven around the block since then.

I have read some threads but the brake and turn signal issues seem really out there.


thanks

 

Hi and welcome back !!
With the "start and stall" you MAY have a serial data bus issue...a lab scope and a CAN break out box can quickly diagnose this...when you turn the key to on does the gas gauge go to empty and water temp maxes out and the DIC messages appear...low fuel, reduced engine power service vehicle soon ??...Bill Curlee has documented this condition fairly extensively. Try opening the drivers door and see if you can access the electrical connector under the rubber accordian boot and check the pin fitment there...you can even give it a couple good shakes first before you pull it apart...if no luck there are 2 splice packs or "Star Connectors" they are called...video and picture below...pull the bus bar off the splice pack with the fewer wires...squeeze the ends together and pull it out...it looks like a comb...now see if the car starts...if it doesn't pull the other one but you have to jumper the light green and dark green wires together...this will connect the BCM to PCM...the car needs these 2 jumped for the car to start...try all this and let us know !!

 

I am going to start by checking the grounds. It is a rarely driven 12K miles car that has never seen a drop of rain.

I have driven it once since the mice were in the garage in April. Odd that it ran fine in the driveway for about 5 minutes and made it a few blocks before everything went crazy.

I am seeing more cases of the start and die and dash lights with the brake, but not at the same time.

I feel it is likely electrical at this point.

 

Go in the DIC menu and pull all the codes. The C5 is nice because you can pull PCM, TCM, ABS, BCM, Left Door Module (LDM?), Right Door Module (RDM?), and HVAC codes. The above posts will give you an idea and maybe the codes will confirm and/or help point you in the right direction.

 

 

Codes were..all history codes
C1295 - Brake lam switch open
B2578- RF turn signal monitor circuit
B2583- LF turn signal monitor circuit
B2282 Battery 1 fault
B2284- Battery 2 fault
U1064- Loss of comm BCM
U1096- Loss of comm IPC
U1255 serial data malfunction
U1000- loss of comm

Cleared all

Started car...run only if I gave it gas. Very rough and smelly. Ran about 20 seconds.

Only code to reappear was B0-RFA U1064 H- Loss of comm BCM

 

Troubleshooting any electrical problem always starts with a battery check. I know the car starts but it still could be low. At least check it with a meter across the terminals with key off, a load test would be even better. A bad or under charged battery can cause strange problems in a C5. If it checks good at least you have eliminated one possible cause.

 

2001C52, are you still in the Memphis area? How is the humidity in your area? Is the car garaged in a climate controlled facility?

I would definitely check the battery voltage before start with a digital volt meter, then, with assistance, again while the engine is cranking. Report back with the two voltage readings.

When starting, many electrical functions must occur in a certain sequence. Many of them have their own voltage parameters and if certain of these parameters are not met, it is possible to start the engine but not other essential functions. I've started my 2000 C5 in years past with the battery at 11 volts, but while the starter is cranking the voltage will necessarily drop. This would result in the engine running but other functions not being activated and the car would not perform correctly. This is why it's important to check the battery voltages in the above manner, and directly off of the battery if at all possible.

Based on your video's I would however expect you will find some wiring/connector issues are occurring. A few items that come to mind; 1) Possible corrosion in the battery compartment. Not very likely because of the Red Top AGM, but easily eliminated as a problem. 2) Moisture in the BCM compartment. Even if not driven in the rain, plugged udders can result in A/C condensation saturating the BCM compartment. 3) A malfunctioning ignition switch can result in some quite strange electrical issues.

All of these things have been covered here on the Forum a number of times and a quick search on each topic should provide some trouble shooting diagnostic guidance for each of them.

Good luck, and please keep us informed...

GUSTO

 

I am not longer in the Memphis area. Garage is pretty dry and not any condensation.

I will start with the battery today. Have to move area thing in the garage. It is under the left and plan on trying to push it on.

Going to take the red top and have it tested. I am thinking it might be 12 years old.

One thing I did not mention is i received the remove key and wait message yesterday. I never did anything to mitigate the column lock issues and never have the problem. Never even did the factory recall.

 

It was probably triggered by a weak battery. Have it fully charged and load-tested. It would be wise to consider an LMC5.

 

Have you contacted a mod regarding this? I'm sure they can help you recover your old account.

 

I had the battery tested and it tested bad.

I bought a new red top and installed it. All the issues continue.

I have read alot about the start/die issues and the issues with pressing the brakes causing craziness with the dash lights. I have not found any cases of someone having both issues.

I will start checking grounds next. Thanks for the help, I will keep everyone posted.

 

Doubt it’s a bad ground !!...which ground or grounds will you be checking ??...with those “U” codes which are data bus communication codes that were history and may be current I would go that diagnostic route !!...good luck !!

 

Can you explain what you mean by diagnostic route?

 

A better term is the diagnostic process...hope these 2 videos helps !!...without a scan tool to look at all the modules in the car, a DVOM, and a basic knowledge of automotive electrical systems this can be a tough one to diagnose !!

 

As I mentioned above, this was probably triggered by the battery being weak, and your battery was confirmed to be bad.

The only way to really eliminate this problem is to install an LMC5. The fact that you didn't "contaminate" your car with other pseudo solutions, none of which really worked, will help to make it a clean and straightforward process this time. I suggest you strongly consider an LMC5.

 

Those codes indicate that there are problems with the Serial Data Bus. This should be your priority, and you were given a troubleshooting process to that effect (quoted below in blue). Follow it and let us know how it goes:

Quote:

Originally Posted by C5 Diag

...there are 2 splice packs or "Star Connectors" they are called...video and picture below...pull the bus bar off the splice pack with the fewer wires...squeeze the ends together and pull it out...it looks like a comb...now see if the car starts...if it doesn't pull the other one but you have to jumper the light green and dark green wires together...this will connect the BCM to PCM...the car needs these 2 jumped for the car to start...try all this and let us know !!...

 

I have tried disconnecting the the 2 splice packs separately. I still need try with the wires jumped.

I am not sure this is classic stop/die like I see in other videos. Plus, the terrible smell makes me think it could be the gas. Aside from that, there is still the electrical issues with brakes and blinkers. Seems like it has to be related but I wanted to share a video of the start cycle with the 4 wire splice pack disconnected.

 

When you open the Star Connector 1, you must jump together the LT GRN and DK GRN wires, to connect the BCM to the PCM, or the car won't start:

 

I have the lock of the back of the splice pack. What is the best option for releasing the DK and LT green wires so I can jump them?