MPU Operational State indicates Motor Disabled, but no explicit reason is given
• Check batteries. • Check electrical connections for corrosion, and check tightening torque on nuts. - Gently remove the MPU pole cover, and inspect the positive and negative terminals (M53::B2 and M53::B1). - Thoroughly inspect the plus pole cable ring terminal, the associated M6 nut, and the cable wire where it is crimped to the ring terminal, for corrosion. >> If corroded, the ring terminal, nut and wire/cable, must be replaced as a set. >> If the terminal screw on the MPU::eMotor is badly corroded, the eMotor must be replaced as well. - MPU grounding point in frame (G77) - Fuse box (P11) • Check power supply wiring to MPU, for abration damage etc. (open circuit, or short circuit). • Check MPU internal voltage sensor: Measure the supply voltage between signal and ground. - Switch on battery (connections / master switch) and ignition key (15). - Measure voltage on MPU power terminals (M6 screws), using a multi-meter device. It should be approximately 24 volt (battery voltage). - Compare measured value to value read from CID 0xF487 (MPU supply voltage), using SDP3. - If there is a significant divergence/difference (more than 5 volt) the electric motor (M53) in the MPU has to be replaced. - N.B. Make sure to compare values, from multi-meter and SDP3, sampled at the same time (as battery voltage can fluctuate over time, depending on active consumers). • Check electric motor (M53) in MPU unit for hardware faults. Replace if necessary.
What you'll see
No driver-visible symptom recorded.
System reaction
Red Steer tag axle fault warn EST in released or fixed mode
Diagnostic depth
The MPU CAN signal Operational State indicates Motor Disabled, but no triggering/explaining Cut Off reason is given (in thier respective CAN signals). This scenario should never occur - there should always be a CutOff reason given when the motor is disabled. This could however be caused by a poor power supply connection.
• Defect connectors/connections (e.g. corrosion) - MPU positive pole connection defect - MPU negative pole connection defect - MPU ground connection in frame defect • Defect wiring - MPU power supply or ground harness • Defect vehicle batteries • MPU electric motor hardware failure