Mazda CX-70 Plug-In Hybrid 2024–2026 — technical service bulletin
Bulletin 09-027-26 · NHTSA communication 11037628 · issued Sep 29, 2026
Technical service bulletin
communication type
Engine
component
2024–2026
model years
5
vehicle entries
Official summary
DESCRIPTION Some CX-70 and CX-90 PHEV vehicles may fail to start (enter READY mode) in cold weather, but the vehicle can often be started successfully on the next attempt. This may occur when leakage current between connector terminals causes the MAIN Relay to be falsely detected as ON. As a result, the Battery ECU may incorrectly determine the relay status, preventing READY mode activation and resulting in a no-start condition. One or more of the following DTCs may be stored: P0AB9, U0100, U0110, and U0115 and multiple warning lights may also turn on. This is caused by corrosion of the connec
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.