DTC C1A05-26: Left Rear Height Sensor - Signal rate of change below threshold: Action

NOTE: If any height sensor fixings are slackened, found to be loose or if a new height sensor is installed, the vehicle ride height MUST be re-calibrated.

Check height sensor linkage is securely connected and not damaged. Visually inspect the height sensor for security, damage and correct orientation/installation. Check the sensor connector for damage. Repair/renew as required, clear DTC and retest
If fault persists, refer to the appropriate system wiring diagrams and check rear left height sensor circuit for short circuit to ground, short circuit to power, open circuit, high resistance. Repair circuit as required, clear DTC and retest