DTC U0001-88; U0100; U0101; U0121; U0121-87; U0131; U0140; U0146; U0151; U0155; Module Communication Errors: Notes

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DETECTION CONDITION & POSSIBLE CAUSE

Description	U0001:88 Module communication error (HS-CAN) U0100:00 Communication error with PCM U0101:00 Communication error with TCM U0121:00 Communication error with DSC HU/CM U0121:87 Communication error with DSC HU/CM U0131:00 Communication error with electric power steering (EPS) control module U0140:00 Communication error with front body control module (FBCM) U0146:00 Communication error with instrument cluster U0151:00 Communication error with SAS control module U0155:00 Communication error with instrument cluster
Detection condition	U0001:88 Start stop unit detects the CAN bus communication line (HS-CAN) malfunction 10 times continuously with the ignition switched ON (engine off or on). U0100:00 Start stop unit could not receive the CAN signal from the PCM for 1 s or more with the ignition switched ON (engine off or on). U0101:00 Start stop unit could not receive the CAN signal from the TCM for 1 s or more with the ignition switched ON (engine off or on). U0121:00 Start stop unit could not receive the CAN signal from the DSC HU/CM for 1 s or more with the ignition switched ON (engine off or on). U0121:87 Start stop unit could not receive the CAN signal from the DSC HU/CM for 10 s or more with the ignition switched off. U0131:00 Start stop unit could not receive the CAN signal from the electric power steering (EPS) control module for 1.2 s or more with the ignition switched ON (engine off or on). U0140:00 Start stop unit could not receive the CAN signal from the front body control module (FBCM) for 5 s or more with the ignition switched ON (engine off or on). U0146:00 Start stop unit could not receive the CAN signal from the instrument cluster for 5 s or more with the ignition switched ON (engine of f or on). U0151:00 Start stop unit could not receive the CAN signal from the SAS control module for 1 s or more with the ignition switched ON (engine off or on). U0155:00 Start stop unit could not receive the CAN signal from the instrument cluster for 5 s or more with the ignition switched ON (engine off or on).
Fail-safe	U0001:88 Sets to default signal. Cancel the i-stop control. (With i-stop system) U0100:00 Sets to default signal. Cancel the i-stop control. (With i-stop system) U0101:00 Sets to default signal. U0121:00 Sets to default signal. U0121:87 Sets to default signal. U0131:00 Sets to default signal. U0140:00 Sets to default signal. U0146:00 Sets to default signal. U0151:00 Sets to default signal. U0155:00 Sets to default signal.
Possible cause	Malfunction in CAN bus communication line Malfunction in CAN line between PCM and start stop unit Malfunction in CAN line between TCM and start stop unit Malfunction in CAN line between DSC HU/CM and start stop unit Malfunction in CAN line between electric power steering (EPS) control module and start stop unit Malfunction in CAN line between front body control module (FBCM) and start stop unit Malfunction in CAN line between SAS control module and start stop unit Malfunction in CAN line between instrument cluster and start stop unit
System wiring diagram	Not applicable