Motor Pump Unit (MPU) seems to be out of control
Check if other MPU related trouble codes are active or passive, if so focus on Electric Motor in MPU. Check for available software updates/campaigns. If the fault is active: 1. Turn the ignition key to OFF, and wait for 10 seconds. 2. Turn battery master switch off (if not available - remove negative battery pole connector), and wait for 10 seconds. 4. Turn battery master switch and ignition key ON. 5. Perform a Diagnostic SelfTest (requires Parking Brake to be applied). The SelfTest will perform an automatic functional performance check of the system. • If the fault disappears (Red Stop Lamp is turned off, and DTC is set passive): - Test drive the vehicle, at speeds below 30 km/h, by turning the steering wheel from side to side. Ceck if the fault reappears. • If the fault remains: - Check the CVU::CPS by turning the tag axle wheels from side to side, while monitoring the signal Piston Postion. If the signal value is implausible repair/replace the CVU.
What you'll see
No driver-visible symptom recorded.
System reaction
Red Steer tag axle fault warn EST in released mode
Diagnostic depth
The MPU electric motor seems to be out of control (does not follow the requested rotational speed).
• Software flaws • MPU electronic hardware failure • CVU mechanical failure (magnet ring for CPS has come loose)