Check Eng Light Both O2 heater??

pokeyl

I can't see them both failing at the same time. 15 amp fuse is good. Is there a relay? Anyone have a wiring diagram?

Thanks in advance!

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It's not my fault I'm old, I was born a very long time ago!

JimmyK

Hey man, the factory service manuals (the FSM) are available online.

The only relay that stands before fuse number 46 (which is the 15 amp fuse that you're referring to) is the ignition relay which is located inside the IPDM E/R fuse box. The relay is between the fuse and the battery power. That fuse powers both the upstream A/F ratio sensors, as well as both heated oxygen sensors, and luckily nothing else it seems.

The heated oxygen sensors have four pins each, one of which is connected to the fuse. The other three connections are to the ECU, one for sensor voltage, the second for sensor, ground, and the third for heater voltage.

The relay is upwind to a bunch of other relays in the car, so maybe its something downwind, be it wiring in the IPDM, harnessing all the way up until the sensors, or something weird going on in the ECU. That said, I don't know much beyond the diagrams, so trust the sage advice from anyone else, just figured I would give you the information.

JimmyK

Any progress or luck?