What does it mean?
B1990 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Electric Steering Column Lock (ESCL) Battery Short Circuit To Ground .
Symptoms
- No start condition with a steering lock warning on the display
- Steering stays locked and the vehicle cannot be moved
- Fuse for the lock circuit blows again as soon as it is replaced
- Security or immobiliser indicator stays lit
- Fault appears after heavy rain, a car wash or work carried out on the column
Likely causes
- Feed wire chafed to the column casting or a bracket where the loom flexes
- Water intrusion into the lock connector or the column area from a leaking screen seal or heater matrix
- Shorted winding in the lock actuator motor
- Crushed harness after column, airbag or lower dash panel work
- Screw or clip driven through the loom during accessory installation
- Corroded terminals bridging the feed to the housing
- Damaged supply driver inside the control unit that powers the lock
How to fix it
- Check the fuse feeding the steering column lock and note whether it has failed
- Disconnect the lock actuator and measure its feed wire to ground, a low resistance confirms the short
- If the short disappears with the actuator unplugged, measure the actuator winding, a shorted motor condemns the lock unit
- Trace the harness from the control unit to the lock, flexing it at the column adjustment while measuring
- Inspect the connector and the column area for water, corrosion and heater or screen leaks
- Repair the shorted wiring, fit a new fuse and recheck the circuit before energising the system
- Replace the lock unit when its motor is shorted, then clear the codes and confirm normal locking and starting