ABS CODE C1236 & C1243

:shrug01: Hey, Just checking to see if anyone can give me some help to resolve the codes I have been getting intermittently when I start up the car: c1236(low system supply voltage) and c1243( BPMV pump motor stalled). This disables the ABS and Traction Control system and I get those nice colored ABS/Traction control lites on the dash. It doesn't happen all the time and when it does I can shut off the car, hit reset 3 times to clear the code and when I restart the car everything is normal. One time the code threw when I dis-engadged the emergency brake and again I shut off the car and hit reset, started back up and all was normal. Any ideas would be helpful. Thanks Phil:dancer01:

cwbeachbum said:

:shrug01: Hey, Just checking to see if anyone can give me some help to resolve the codes I have been getting intermittently when I start up the car: c1236(low system supply voltage) and c1243( BPMV pump motor stalled). This disables the ABS and Traction Control system and I get those nice colored ABS/Traction control lites on the dash. It doesn't happen all the time and when it does I can shut off the car, hit reset 3 times to clear the code and when I restart the car everything is normal. One time the code threw when I dis-engadged the emergency brake and again I shut off the car and hit reset, started back up and all was normal. Any ideas would be helpful. Thanks Phil:dancer01:

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Clean the grounds to the frame behind the Right and Left Head Lamp, The one below the battery on the frame and the one below the power brake booster on the frame!!! Dump the codes and Drive it!!!If they come back we will go from there!!:thumbsup:

reply to codes reply

Thanks for the advice. I'll try to clean the grounds saturday if it's not raining here at clearwater beach. I have a schematic I downloaded a while back that shows the front mounted EBTCM/BPM groundpoints. Are you talking about the grounds numbered 101,102 & 103? The article I read stated the connectors inside the boxs get corrosion on the contacts and that causes problems. Am I on the right track? Also should I disconnect the battery positive terminal first before I clean the grounds ? Thanks for you help Phil:thumbsup:

cwbeachbum said:

Thanks for the advice. I'll try to clean the grounds saturday if it's not raining here at clearwater beach. I have a schematic I downloaded a while back that shows the front mounted EBTCM/BPM groundpoints. Are you talking about the grounds numbered 101,102 & 103? The article I read stated the connectors inside the boxs get corrosion on the contacts and that causes problems. Am I on the right track? Also should I disconnect the battery positive terminal first before I clean the grounds ? Thanks for you help Phil:thumbsup:

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Yes,You got it right!!! Take them all apart and be sure that they are clean and making good connection!!:thumbsup: :thumbsup:

Thanks

:thumbsup: Thanks again. I'll let you know how I make out. :dancer01:

I'd load test the battery first!!! start with the simplest code.... low system voltage at start-up might just mean your battery voltage drops below 10v..... once that happens all kind of meaningless codes can start showing up!

Hi gmjunkie, I cleaned the grounds last weekend. Took them apart and there wasn't much white build up and I used CRC 2-26 that the electrician at Home Depot recommended to clean the contact and lubricate them to prevent corrosion. Also did the battery terminals after a light sanding also with light sand paper. The codes came back a few days later on and off again. Some times I can start the car and no DIC warning then other times I get the warning about servicing the ABS/traction control. I did notice that dwhen I turn the key to accessory the volt meter needle does go to to top most setting and then drops down to below 10 volts so I was wondering if JC swm had the solution. Any way here are the codes I found tonight: All were historical but one under the air conditioning section 99HVAC was historical and current. The two ac codes have been on the car since I purchased it last year. B0361 H & B0441 H C,
Under 28TCS C1243 H, Under 60IPC U1160 H
Appreciate any advice or direction to go next. The car run great and the air works great. It's just annoying when the DIC warnings pop up.
Thanks, cwbeachbum

cwbeachbum said:

Hi gmjunkie, I cleaned the grounds last weekend. Took them apart and there wasn't much white build up and I used CRC 2-26 that the electrician at Home Depot recommended to clean the contact and lubricate them to prevent corrosion. Also did the battery terminals after a light sanding also with light sand paper. The codes came back a few days later on and off again. Some times I can start the car and no DIC warning then other times I get the warning about servicing the ABS/traction control. I did notice that dwhen I turn the key to accessory the volt meter needle does go to to top most setting and then drops down to below 10 volts so I was wondering if JC swm had the solution. Any way here are the codes I found tonight: All were historical but one under the air conditioning section 99HVAC was historical and current. The two ac codes have been on the car since I purchased it last year. B0361 H & B0441 H C,
Under 28TCS C1243 H, Under 60IPC U1160 H
Appreciate any advice or direction to go next. The car run great and the air works great. It's just annoying when the DIC warnings pop up.
Thanks, cwbeachbum

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As JCswm said Low Battery voltage can cause problems and all sorts of weird codes!!! Charging the battery hooked up to the car can,(Not always,But usually) Scramble the ECM!! You said that the Voltage Dropped below 10!! Now we know it's not in the grounds,which is a common problem in C5's!!(Probably 60-80% of the time in my experience!!) 1. I'd be checking your battery as a Suspect!! Disconnect,Charge and Load Test!!(If OK) 2.Check alternator for bad Diodes, Brushes and Regulator!!If Questionable this could be not delivering enough Power to Keep Battery Fully Charged or excessive AC voltage could be slipping past the diodes, a Battery will not except AC voltage and will often cause it to boil and Burn it up!! (This really should be checked anytime when replacing the Battery!!) (I had a Problem with my 03 this spring and it was throwing all sorts of weird codes!! I ended up changing out the battery and then I was able to get to the Problem I was having with the TCS which ended up being a Faulty EBCM with a open solenoid circuit!!! This was a problem that was able to be repaired,I sent it off to ABSFixer and they Up dated the EBCM with NEW Heavier Solenoid Coils!!) However, This is not your problem,but Low voltage could be!! Low Battery voltage can stall the abs pump motor,can even cause it to over heat and Cook it!!! In any case How Old is the battery?? Is it Original?? The battery voltage,a good Strong Battery should really never drop below 11.- 12.volts Cranking!! And should have 12.5-13.5 volts without a load!! In the Old days without all the Fancy Computers you could run a car off the Generator or Alternator and it would run till you shut it off,not so anymore!! The Battery has to be in place to Store DC voltage and help eliminate AC ripple from the Alternator,Kinda like a Surge protector on you Computer!!:thumbsup: Hope I made some sense,I'm HillBilly you know!!!!:lmao::thumbsup: