What does it mean?
B1628 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Module Configuration Conflict .
Symptoms
- Reverse lamps do not come on when reverse is selected
- Reversing camera does not switch on and the display stays on the previous screen
- Mirror tilt down in reverse stops working
- Rear parking sensors do not activate when reverse is engaged
- Reverse warning sound and any wiper behaviour tied to reverse no longer function
- On the configuration variant, several features behave as if fitted to a different specification level
Likely causes
- Open circuit in the wire between the transmission range switch or shifter assembly and the module
- Worn or misadjusted transmission range switch that never closes the reverse contact
- Corroded connector at the transmission, common where road salt and water reach the case
- Broken wire in the console loom under the shifter
- Corroded or loose module ground affecting the input reference
- Module input open internally
- On applications where this code refers to configuration, a replacement module carrying settings that do not match the vehicle build
How to fix it
- With the vehicle safely secured and the brake applied, watch the reverse input in live data while selecting reverse
- If the state never changes, back-probe the reverse signal at the module to see whether the signal reaches it
- Check the transmission range switch adjustment before assuming an electrical fault, as a misadjusted switch is a frequent cause
- Inspect the connector at the transmission for corrosion, water and pushed-back terminals
- Check continuity from the range switch to the module, flexing the console and underbody loom while measuring
- Verify the module ground with a voltage drop test, then adjust or replace the range switch if it fails a continuity test
- On the configuration variant, read the stored module configuration and reprogram it to match the vehicle build data