Case Study - B11ED Rear Door Control Module - Supply Voltage too Low



Ross-Tech Employee
Staff member
Ross-Tech Employee
Jan 29, 2014
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2011 Jetta (USA market vehicle), left rear door latch power lock would not operated. As I understand it, tech got this car after it was blasted with the parts cannon. Both left door modules replaced, left rear door latch also replaced... still no left rear door power lock operation. Snippet from Auto-Scan when I was on phone with customer:

Address 42: Door Elect, Driver (J386) Labels:| 3C0-959-70X-GEN4.clb
Part No SW: 561 959 701 C HW: 3C0 959 793 J
Component: TUER-SG FT 002 0601
Revision: 12100010 Serial number: 0011016859
Coding: 0004B5
Shop #: WSC 09972 002 104857
ASAM Dataset: EV_TSGFPQ35BRFVW46X A04004
VCID: 1E39D4E301666E7601-804A

Slave Driver:
Subsystem 1 - Part No SW: 3C0 959 703 C HW: 3C0 959 795 D Labels: 1K0-959-70X-GEN4.CLB
Component: J388__TSG-HL 009 1509
Serial number: 00000009088605
Coding: 00A090

1 Fault Found:
131329 - Rear Door Control Module
B11ED F0 [009] - Supply Voltage too Low
Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Reset counter: 21
Mileage: 159178 km
Date: 2020.11.06
Time: 01:25:42
It was learned that the code could be cleared out and would not come back until power locks were operated (with said left rear not working). Running the left rear door power window showed it was working to factory design and no codes flagged. The tech load tested the main power and ground to the left rear door module (J927). /10 (positive) and /9 (ground) seem to carry load with no voltage drop issue, these are 2.5mm² wires.

However, /11 of the J927 also needs power... and it was a dead terminal. Depending on the production run, how /11 gets powered can vary. In this case, the door wiring harness, the main power going in, the wire splits into 2 wires, on being the 2.5mm² that goes to /10 and a smaller 0.5mm² that goes to /11. So a damaged electrical path (wire) in the door harness itself. Tech did a quick and dirty jumper wire to terminals /10 to /11 and the power lock then worked to factory design.

Tech will dig into door wiring harness and repair failed wire. Bonus points... I don't care what world you live in and where you get your packages... you might be better serves getting parts from the dealer. Note the part number of the J386 driver's door control modules.... .does that look like a part that goes in a 2011 Jetta. I won't say it is the wrong part.... but I find no proof it is the correct part for a 2011 Jetta. As such, I emailed the tech suggesting to put the original door modules back into the car once the wire is fixed.