Getting Code 1271 - Only when parking lights are on
Thread Starter
Burning Brakes
Joined: Jun 2014
Posts: 799
Likes: 160
From: Landenberg PA
Getting Code 1271 - Only when parking lights are on
Hi folks, I posted about getting this code last year. It basically did not come back for a while and now I figured out under what conditions it does. I can drive the car all day long w/o getting the code, however if I turn the parking lights on, I get the code.
I clear the code shut off the lights and no code? Trying to figure this one out. Any suggestions (no wises *** responses, like keep the lights off
) please. Thanks in Advance.
I clear the code shut off the lights and no code? Trying to figure this one out. Any suggestions (no wises *** responses, like keep the lights off
) please. Thanks in Advance.
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
Two seemingly unrelated items. Maybe a couple pinched wires? When you turn on the lights maybe the wiring for the valve is being shorted to ground or voltage. See if you can check the wire at the EBTCM connector and see if the readings change when you turn the parking lights on. Just a guess.
*C1271 LF TCS Master Cylinder Isolation Valve Malfunction EBTCM ABS/TCS
Check that the grounds G101 for BPMV and G108 for the EBTCM are clean and tight.
6/19/17
I looked at the schematic for that valve and the circuit is inside the ECBM/BPMV assembly. The fact that this only happens when you turn the parking lights on makes me think that you have an issue with power to the EBTCM/ BPMV or grounds. Check all the voltage inputs but take a really good look at the ignition positive voltage. Ignition switch is a common failure. The troubleshooting procedure tells you to disassemble the EBTCM and BPMV and check the connections between the two, but if that was the problem I don't see how it would just happen when you put the parking lamps on.
2000 C5
*C1271 LF TCS Master Cylinder Isolation Valve Malfunction EBTCM ABS/TCS
Check that the grounds G101 for BPMV and G108 for the EBTCM are clean and tight.
6/19/17
I looked at the schematic for that valve and the circuit is inside the ECBM/BPMV assembly. The fact that this only happens when you turn the parking lights on makes me think that you have an issue with power to the EBTCM/ BPMV or grounds. Check all the voltage inputs but take a really good look at the ignition positive voltage. Ignition switch is a common failure. The troubleshooting procedure tells you to disassemble the EBTCM and BPMV and check the connections between the two, but if that was the problem I don't see how it would just happen when you put the parking lamps on.
2000 C5
Last edited by Greg_E; Jun 19, 2017 at 08:39 AM.
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
Disassembling the EBTCM/BPMV would be the last thing I would do. You need to check power and grounds first.
Drifting
Joined: Oct 2011
Posts: 1,872
Likes: 333
From: Olmsted Falls Ohio
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