DTC U0115; Communication Error To Pcm: 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

DTC U0115:00	Communication Error to PCM (local CAN between TCM and PCM)
DETECTION CONDITION	Under the following condition, the TCM cannot receive the signal from PCM (local CAN between TCM and PCM): Battery voltage is 10 V or more.
FAIL-SAFE FUNCTION	Set to TCC control. Inhibits learning control. Inhibits manual mode. Inhibits neutral idle control. Inhibits AAS. Inhibits 5GR and 6GR. Inhibits shift down when the accelerator pedal is depressed.
POSSIBLE CAUSE	PCM DTC is stored. PCM malfunction TCM malfunction
SYSTEM WIRING DIAGRAM	Not applicable