U0321
Software Incompatibility with Ride Level Control Module
- Severity
- Medium
- Driving
- Drivable — book it in
The software in the ride level control module is not compatible with the rest of the vehicle. Air suspension or adaptive damping will fall back to whatever its failure position is. On an air-sprung vehicle that can mean the car settling overnight until it sits on its bump stops, which is uncomfortable, damaging and unpleasant on a rough road.
Possible causes
- CommonThe ride level control module replaced but never coded to this vehicle
- CommonUsed module fitted from a different vehicle or suspension specification
- CommonRide height calibration not performed after fitting
- CommonSoftware update interrupted during programming
- CommonWrong part number for the suspension variant
What you might notice
- Vehicle sitting low, or at an uneven height
- Suspension warning message
- Ride height not adjusting
- Harsh ride
- Fault present since suspension work
What to check, in order
- Check the ride height at all four corners. A car sitting on its bump stops should be driven gently and slowly, not normally.
- Ask what was done. Suspension or module work immediately before this appeared is the explanation.
- Check whether the ride height calibration was performed after fitting - it is a required step and skipping it produces exactly this.
- Check the part number against the vehicle's suspension variant.
- Note that headlamp aim follows ride height on many vehicles, so a car sitting wrong may also be dazzling oncoming drivers.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
U00xxU01xxU02xxU03xxU04xxU05xxU06xxU07xxU08xxU09xxU0AxxU0BxxU0CxxU0DxxU0ExxU0FxxU10xxU11xxU12xxU13xxU14xxU15xxU16xxU17xxU18xxU19xxU1AxxU1BxxU1CxxU1DxxU1ExxU1FxxU20xxU21xxU22xxU23xxU24xxU25xxU26xxU27xxU28xxU29xxU2AxxU2BxxU2CxxU2DxxU2ExxU2FxxU30xxU31xxU32xxU33xxU34xxU35xxU36xxU37xxU38xxU39xxU3AxxU3BxxU3CxxU3DxxU3ExxU3Fxx