C1780: OBD-II code C1780 flags loss of the steering angle signal at the suspension controller — pitch and roll compensation cannot be commanded until the signal returns.

Symptoms

• The 'Service Ride Control' warning is displayed and suspension damping loses its steering-input compensation.
• Body roll may feel less controlled during cornering because the module cannot pre-stiffen dampers for turn-in.
• Multiple stability control codes may accompany this one when the steering angle sensor is the true root cause.

Common causes

• A serial data bus fault preventing steering-angle messages from the ABS/ESC module from reaching the suspension controller.
• A failed steering angle sensor with a lost, biased, or noisy signal — usually paired with C1286-C1288.
• Damaged wiring on the shared bus or a bad splice interrupting the signal path.

What to do?

Scan every module for U-codes and check ABS/ESC codes for steering-angle sensor faults — fix those first. Verify the suspension controller receives valid steering-angle data with a scan tool. Repair wiring or recalibrate the sensor as needed.