BRM no start no ECM communication

bc1550

Active member
Joined
Mar 6, 2024
Location
Oregon
TDI
2006 Jetta BRM/MT
Howdy,
I have an issue with intermittent stalling and no start. I'm either getting ecm code 1314 or 1100.

I'm chasing the wiring and connections to the ECM and am looking at the relay.

Everything I see (Bently, web searches) has referenced a 458 relay, but I have a 100.

Do I have the wrong relay or is a 100 common too?

Best I can tell, the 458 has what I think is a diode (or some extra connection) and is 40A rated vs the 100 is 70A & no diode.


TIA
 
Last edited:

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2002 Golf 6MT; 2015 Sportwagen 6MT; 2016 A3 e-tron 6DSG
BRM weird electrical issues? After probably 10hrs of chasing issues and repairing wires here and there that I figured would fix the problem, I took @oilhammer's advice and replaced the engine wiring harness.
Problem(s) fixed.

BRM have a reputation for wiring going bad due to the multitude of tight bends and twists and friction points. And good luck finding where in the wiring bundle the issue is. Might be a a relay, but.....
 

bc1550

Active member
Joined
Mar 6, 2024
Location
Oregon
TDI
2006 Jetta BRM/MT
After digging around more, it turns out the 100 and 458 relays are interchangeable. It also seems this relay is a somewhat common issue. I couldn't really source the 100 as easily as the 458, so I got a 458 and hoping that's my issue.
 

borninabus

Veteran Member
Joined
Feb 18, 2020
Location
Arizona
TDI
-2013 JSW 6MT- -2006 Jetta DSG-
have you done any testing on the ignition switch itself?
just a suggestion. good luck :)
 

bc1550

Active member
Joined
Mar 6, 2024
Location
Oregon
TDI
2006 Jetta BRM/MT
have you done any testing on the ignition switch itself?
just a suggestion. good luck :)
I didn't really think to, no. Since it was turning on and cranking (but getting no comm errors to ECM), I didn't think the ignition switch would be the culprit. Thank you for the suggestion though. :)

It's been running well (minus what seems like a turbo issue) for a couple of days, and I just put in a new ECM relay yesterday. So... we'll see.
 

bc1550

Active member
Joined
Mar 6, 2024
Location
Oregon
TDI
2006 Jetta BRM/MT
I edited the title of this thread to see if I can solicit some assistance (rather than resurrecting an old thread).
I don't have the car right now, as it died out of town.

This describes the problem I'm having, but I can't find any info.
No glow light,no start 06 jetta | TDIClub Forums

@Rx7145 asked if the previous person had tach on crank, I do not, but that would be expected as the ECM doesn't seem to be communicating with the rest of the car.

I saw a post about checking reference voltage on a ECM connected sensor to see if the ECM is output voltage. I have not done this yet, but It was stated that if it didn't than the ECM is bad. I'm not sure this is correct since there may be a chance the ECM is not getting power. Thoughts?

This problem is intermittent, so it's hard to troubleshoot, but I believe I tested voltage to the ECM when I had this problem, and it was fine (and not shorted). I will test this again.

I'm getting the car back home next week, but I was hoping I get some more insight on what I could look into.

Thank you.
 
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