What does it mean?
B1610 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Ambient Light Sensor 1 Input Circuit Low .
Symptoms
- Interior lamps stay on permanently and do not switch off with the doors closed
- Cluster shows a door open although every door is shut
- Alarm will not arm and the vehicle can be left unprotected
- Parasitic drain flattens the battery within a day or two
- On the light sensor variant, headlamps and dash dimming behave as if it is dark all the time
Likely causes
- Illuminated entry input wire chafed against body metal or a door frame, pulling the circuit to ground
- Door latch switch stuck closed or shorted internally
- Connector terminal bent onto a ground pin
- Water and corrosion in a door or kick panel connector
- Harness damage from a previous speaker, trim or accessory installation
- Module input stage pulled low internally
- On applications where this code refers to lighting control, an ambient light sensor signal reading low from a shorted sensor, a harness short to ground, or the sensor covered by a mat or sticker
How to fix it
- Unplug the door latch connectors one at a time and watch which one stops the code and turns the lamps off
- With the suspect branch disconnected, ohm the input wire to ground; a near-zero reading confirms the short
- Inspect the hinge boot loom and the kick panel connectors for water and chafe, since both are common entry points
- Check the door drains and vapour barrier, because water in the door is often the root cause
- Test any suspect latch on its own; replace it if the switch measures low to ground when released
- Repair and re-route the shorted wire clear of metal edges rather than only insulating it
- On the light sensor variant, uncover the sensor, back-probe its signal against specification and check the harness for a short to ground