Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2006 Mazda MPV ESFACTORY OEM SERVICE PROCEDURE

DTC U0101: Notes

DTC U0101 [AJ] DETECTION CONDITION AND POSSIBLE CAUSES

DTC U0101

PCM cannot receive any signals from TCM

DETECTION CONDITION

PCM cannot receive any signals from TCM.

Diagnostic support note

This is a continuous monitor (CCM).
The MIL illuminates if the PCM detects the above malfunction condition in the first drive cycle.
PENDING CODE is available if the PCM detects the above malfunction condition.
DTC is stored in the PCM memory.

POSSIBLE CAUSE

Short to ground circuit between TCM terminal 2J and PCM terminal 66
Short to ground circuit between TCM terminal 2M and PCM terminal 92
Open circuit between TCM terminal 2J and PCM terminal 66
Open circuit between TCM terminal 2M and PCM terminal 92
Short to power circuit between TCM terminal 2J and PCM terminal 66
Short to power circuit between TCM terminal 2M and PCM terminal 92
Damaged TCM
Damaged PCM

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.