DTC U0001-88, U0100-00, U0121-00, U0140-00 Or U2121-00: Communication Error (Electric Power Steering (EPS) (Us)): Outline

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

DTC U0001:88 OR U2121:00 (ELECTRIC POWER STEERING (EPS) (US)) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	DTC U0001:88	CAN system communication error
	DTC U0100:00	Communication error to PCM
	DTC U0121:00	Communication error to DSC HU/CM
	DTC U0140:00 or U2121:00	Communication error to body control module (BCM)
Detection condition		U0001:88 Error detected in line between CAN connection module and CAN bus communication line U0100:00 Communication error to PCM is detected in CAN communication U0121:00 Communication error to DSC HU/CM is detected in CAN communication U0140:00 or U2121:00 Communication error to body control module (BCM) is detected in CAN communication
Fail-safe		Refer to "Fail-safe Function Table". (See DTC TABLE (ELECTRIC POWER STEERING (EPS) (US)) .)
Possible cause		CAN system wiring harness open or short circuit with PCM CAN system wiring harness open or short circuit with DSC HU/CM CAN system wiring harness open or short circuit with body control module (BCM) Poor connection at connectors
System wiring diagram		Not applicable
Connector diagram		Not applicable