Our 2003 has 292,500+ miles on it and started having a stumble at the beginning of accelerating from a stop. Replaced plugs and coils as it was throwing a relevant code. Also cleaned throttle body and MAF. Ran fine for a few weeks and now went into limp mode. Silly me took it in to the dealer asking them to do a deep scan and provide me a readout of DTCs with INFs, and Live Data. They basically gave me what I already knew P3125/302 and said, “ not worth fixing”. Over the phone the service writer had started reading the Live Data related to the DTC, but when I picked it up they did not provide a full printout, despite charging me $205 for the ‘diagnosis’… The P3125/302, indicates a W phase inverter voltage sensor issue as far as I can make out. Does anyone have any suggestions as to how I could further diagnose this?
AIUI about the only thing you can check…unless you're comfortable inspecting the internal electronics of the inverter…are the connections between the converter/inverter and the HV ECU. If they check out ok then it seems replacement is the only other option. There's a couple on eBay…but they're in the UK where I am…so you might be best checking breakers wherever you are. Best of luck, Jay.
