Fault code 00931:008 indicates that the rear right door lock module (F223) is sending a signal that the control unit considers invalid, inconsistent, or outside the expected operating range. In plain English, the vehicle is seeing lock-module feedback from the rear right door that does not match what it expects, which can lead to erratic central locking behavior.
This type of fault is commonly seen on VAG vehicles, including models from Volkswagen, Audi, SEAT, and Škoda, especially when the door wiring, lock mechanism, or internal door electronics begin to fail intermittently.
What Does 00931:008 Mean?
The code 00931:008 – Rear Right Door Lock Module (F223) Implausible Signal means the vehicle has detected a signal from the rear right door lock module that does not match the expected logic or operating state. The signal may be intermittent, contradictory, delayed, or electrically unstable.
In practice, this can happen when the control module commands the rear right door to lock or unlock, but the feedback signal from the lock module does not agree with the expected result. This often points to a wiring fault, poor connection, failing lock assembly, or a problem inside the module itself.
What Does “Implausible Signal” Mean?
An implausible signal does not always mean the component has completely failed. It usually means the signal being received is not believable when compared with the operating conditions, control commands, or other related inputs. For example, the module may report a lock state that changes unexpectedly, conflicts with the commanded position, or drops in and out because of a broken wire or weak connection.
Common Symptoms of 00931:008
- Rear right door does not lock or unlock consistently
- Intermittent central locking problems
- Random unlocking or unexpected lock cycling
- Door status shown incorrectly on the dash or scan tool
- Comfort or convenience system fault codes stored in memory
- Fault appears intermittently rather than staying active all the time
Vehicles Commonly Affected
This fault can appear on a wide range of VW Group vehicles that use electronically monitored door locking systems. Commonly affected vehicles may include:
- Volkswagen Passat
- Volkswagen Golf
- Volkswagen Jetta
- Volkswagen Tiguan
- Volkswagen Caddy
- Audi A4
- Audi A6
- Škoda Octavia
- SEAT Leon
Exact system design can vary by platform and model year, so it is always best to confirm the rear right door lock module designation and wiring layout with the correct factory information for the vehicle you are diagnosing.
Most Common Causes of 00931:008
| Cause | Description |
|---|---|
| Broken wiring in the door loom | Repeated flexing in the rubber boot between the body and door can break wires internally |
| Corroded or loose connectors | Moisture, oxidation, or poor pin contact can distort the signal |
| Failing door lock mechanism | Wear inside the latch or actuator can cause incorrect lock-state feedback |
| Weak power supply or bad ground | Voltage drop or poor ground integrity can make the module behave unpredictably |
| Internal module fault | The rear right door electronics may fail internally and send unstable data |
| Mechanical binding in the latch | A sticking lock can confuse the control logic and trigger implausible feedback |
In many real-world cases, the root cause is found in the rear door wiring harness or the door lock assembly, not necessarily the module itself. That is why basic wiring and voltage checks should always come before replacing parts.
Less Common Causes
- Intermittent CAN or convenience network communication issues
- Water intrusion inside the door
- Previous repair damage or poor-quality wiring repairs
- Control module software or coding issues in rare cases
How to Diagnose 00931:008 Step by Step
1. Confirm the Fault Code
Scan the vehicle with a tool capable of reading body and comfort system faults. Record whether the code is stored as static or intermittent, and check for other door, central locking, or convenience-module codes that may be related.
2. Check Rear Right Door Lock Operation
Operate the central locking system several times and observe whether the rear right door responds correctly every time. Listen for delayed movement, weak actuation, or inconsistent lock behavior.
3. Inspect the Door Harness Carefully
Pull back the rubber wiring boot between the body and the rear right door and inspect the loom closely. Broken conductors often fail internally before the outer insulation shows obvious damage, so gently flex the wires while checking continuity.
4. Verify Power and Ground
- Check for battery voltage at the door lock module or latch assembly where applicable
- Confirm ground integrity with a voltage drop test
- Look for unstable voltage while operating the locks
A poor power or ground connection can easily create implausible feedback signals.
5. Inspect Connectors for Corrosion or Loose Pins
Disconnect the relevant connectors and inspect for green corrosion, water ingress, loose terminals, overheated pins, or signs of previous repair work. Even minor connector resistance can distort the signal enough to set this code intermittently.
6. Test the Door Lock Mechanism
If wiring and power supply checks pass, inspect the rear right door lock or latch assembly. A worn actuator motor, failing internal switch, or sticky mechanical latch can all create contradictory lock-state signals.
7. Evaluate the Module Only After Basic Checks
Do not replace the rear right door lock module first. Only consider module replacement after confirming the harness, connectors, power feed, ground path, and lock mechanism are all working correctly.
Best Repair Strategy
- Repair broken or cracked wires in the rear door harness
- Clean and secure corroded connectors
- Repair poor grounds or voltage supply problems
- Replace the rear right door lock or latch assembly if it fails testing
- Replace the rear right door electronics or module only after all other checks are completed
Estimated Repair Costs
| Repair | Typical Cost Range |
|---|---|
| Basic wiring repair | €0 to €50 DIY, or more at a workshop depending on labor time |
| Connector repair or cleaning | €10 to €60 |
| Door lock or latch replacement | €80 to €200 for parts, depending on model |
| Used replacement module | €30 to €100, depending on part number and coding requirements |
| Workshop labor | €100 to €300 or more depending on access time and diagnosis |
Actual repair costs vary by vehicle, region, and whether used or new parts are installed. On many vehicles, wiring repair is the cheapest and most sensible place to start.
Can You Still Drive with 00931:008?
Yes, in most cases the vehicle is still drivable because this code usually affects the central locking and convenience system rather than engine or brake operation. However, the fault should not be ignored for too long.
- The vehicle may not lock securely
- You may experience random unlocking or failed locking
- The door may not report its status correctly
- Convenience and anti-theft functions may become unreliable
That makes this a moderate-priority repair: the car may still drive normally, but vehicle security and convenience can be affected.
Can You Fix 00931:008 Yourself?
If you are comfortable removing interior trim, using a multimeter, and inspecting wiring, this is often a realistic DIY repair. Many cases are caused by visible or testable wiring faults in the rear door harness. If the fault leads to module coding, advanced scan-tool tests, or latch disassembly, a professional workshop may save time and prevent unnecessary parts replacement.
Important Diagnostic Tip
Do not replace the door lock assembly or module just because the code mentions the rear right door lock module. An implausible-signal fault often means the control unit is seeing bad information, not necessarily that the module itself is dead. Always start with the wiring, connector condition, power feed, and ground path before replacing expensive parts.
Final Verdict
00931:008 – Rear Right Door Lock Module (F223) Implausible Signal usually points to an electrical or mechanical problem affecting the rear right door locking system. In many cases, the fault is caused by damaged door-harness wiring, poor connector contact, or a failing door lock mechanism rather than a completely failed control module.
The smartest approach is to diagnose the fault in order: confirm the code, inspect the rear door harness, verify voltage and ground, check connector condition, and test the lock assembly before considering module replacement. That method reduces guesswork and helps avoid unnecessary costs.
FAQ
What does 00931:008 mean on a VW or Audi?
It means the rear right door lock module is sending a signal the control unit considers invalid or inconsistent. The cause is often wiring damage, connector issues, or a faulty lock assembly.
Can a bad wiring harness cause 00931:008?
Yes. Broken or internally damaged wires in the door loom are one of the most common causes of this fault, especially where the harness bends between the body and the door.
Does 00931:008 mean the rear door lock module is bad?
No. The code points to an implausible signal, but that does not automatically mean the module has failed. Wiring faults, poor grounds, corrosion, and latch problems can all trigger the same code.
Is 00931:008 serious?
It is usually not a drivability issue, but it can affect vehicle security and locking reliability. That makes it important to repair, even if the car still drives normally.
What should I check first for 00931:008?
Start by checking the rear right door harness, especially inside the rubber boot between the door and the body. Then verify power, ground, and connector condition before replacing any parts.