U0155 Diagnostic for 2012 Honda Accord SE: AC Blowing Warm Air and Check Engine Light On
I recently purchased a 2012 Honda Accord SE eight months ago. A day ago, my air conditioning started blowing warm air instead of cool. The next morning, both the traction control light and check engine light came on. This caused me significant concern since I've only owned the vehicle for less than a year. I took the car to a repair shop, which initially diagnosed the issue as U0155 (Communication Issue Between Modules). They tested various components related to the AC system and concluded that a faulty air conditioning compressor might be the cause. However, given that both the traction control and check engine lights turned on immediately after the AC stopped cooling, I'm wondering if this could point to something else — perhaps an electronic communication issue rather than a mechanical failure. I know Honda tends to charge high prices for repairs, so I'm seeking advice on whether there's another possible root cause. Could it be related to a software or wiring problem? Does the AC compressor receive 12V when commanded? And is it possible that the issue stems from an electrical modification (like adding a radio or GPS) or a battery reset? I also found online that AC compressors typically last between 8 to 12 years — so if the system is still under warranty or within normal lifespan, could this be a non-compressor-related fault?
Please confirm the diagnostic code — U0155 is not commonly listed in basic troubleshooting guides. U-series codes indicate communication issues between vehicle modules. Have you made any recent electrical modifications, such as adding a radio or GPS system? I agree that jumping to a faulty compressor is premature. Check if the AC compressor receives 12V when commanded — this helps rule out mechanical failure. Also, traction control and engine light activation may be linked to electronic communication faults.