Audi A3 Central Locking Tailgate Motor (V53) Short to Ground: Diagnosis and Troubleshooting

Experiencing issues with your Audi A3’s central locking system, specifically the tailgate? A common problem indicated by VCDS error code 00950 – Central Locking Motor – tailgate (V53); UNLOCK, 007 – Short to Ground points towards a potential electrical fault. This article will delve into diagnosing this issue on a 2013 Audi A3 8PA TDI, providing insights and steps for troubleshooting before considering module replacements.

One Audi A3 owner encountered this exact problem and utilized VCDS to pinpoint the fault. Measurements were taken to assess the electrical signals reaching the V53 motor, responsible for unlocking the tailgate.

Electrical measurements on Audi A3 tailgate locking motor

The measurements revealed that while other readings appeared normal, a constant 12V supply was present at the V53 motor. This is unusual because voltage should ideally be applied only when the central locking system is activated via the key fob or hatch release button. The continuous voltage suggests a potential short circuit, possibly within the Address 09: Cent. Elect. (J519), the central electronics control module.

The VCDS scan log provides further context, highlighting the fault within the Central Electrics module:

Address 09: Cent. Elect. (J519) Labels:. 8P0-907-063.clb
Part No SW: 8P0 907 063 Q HW: 8P0 907 063 Q
Component: BCM PQ35 M 111 0719 Revision: AM111715 Coding: 6E000A0FA01336E4287241E000100D4D401E62AA104DD128E40008840040
Shop #: WSC 04267 003 1048576 VCID: 42D63997648F5E4A09F-8016
Subsystem 1 - Part No SW: 8P1 955 119 F HW: 8P1 955 119 F Labels: 1KX-955-119.CLB
Component: Wischer AU350 H11 0050 Coding: 00DD13
Subsystem 2 - Part No: 1K0 951 605 F Component: LIN BACKUP HO H01 0009
1 Fault Found:
00950 - Central Locking Motor - tailgate (V53); UNLOCK
            007 - Short to Ground

Before assuming a faulty J519 module and proceeding with replacement, further investigation is recommended. A short to ground could also originate from wiring harness damage within the tailgate itself or the wiring between the tailgate and the central electronics module.

Troubleshooting Steps:

1. Inspect Wiring: Carefully examine the wiring harness that runs to the tailgate, paying close attention to areas where the wires flex, such as hinges. Look for any signs of damage, frayed wires, or broken insulation that could cause a short to ground.
2. V53 Motor Check: Disconnect the V53 motor connector and re-measure the voltage at the connector. If the 12V disappears, the short may be within the motor itself. However, given the “Short to Ground” error, a wiring issue is more probable.
3. Component Isolation: Systematically disconnect components related to the central locking system in the tailgate to isolate the short circuit.

By methodically checking the wiring and components, you can effectively diagnose the root cause of the 00950 error code and potentially avoid unnecessary replacement of the central electronics module (J519). This systematic approach saves both time and cost in resolving Audi A3 central locking malfunctions.