C1252: OBD-II code C1252 flags an invalid normal-force calculation for the left front wheel in the RSS system — damping cannot be optimised for that corner.

Symptoms

• The 'Service Ride Control' warning is displayed on the dashboard, alongside the RSS lamp on some models.
• Left front damper control reverts to a default setting; the ride at that corner can feel disconnected from the other three.
• Body-roll and dive control on the left side may be reduced because the RSS module cannot trust the left-front load input.

Common causes

• A failed left front position or acceleration sensor providing invalid data to the RSS module's normal-force algorithm.
• Damaged or open wiring between the left front corner sensors and the RSS module, especially near the strut tower.
• A calibration issue or software fault in the RSS module that misinterprets otherwise valid sensor data.

What to do?

Read live RSS data and compare left-front position and acceleration values to the other three corners — the errant corner will read implausibly. Inspect the left front sensor wiring and connector. Replace failed sensors and repair wiring. If sensors and wiring are good, the RSS module may need reprogramming or replacement.