I need help,it's getting expensive

[Macscam]

The code p1155 came up on my rav-4,i changed the sensor twice!! $600.00us

I bought a better obd2 reader, erased the dtc. It comes back up. The reader now tells me possible pcm failure.if anyone could help me i would appreciate it very much.

[Perfection]

Make sure you have the correct part in the correct location. The heater circuit has to have the correct resistance range. The PCM checks for the current in the heater circuit.

 

[m4rkw]

@Macscam I'm afraid you've made a very common mistake in your interpretation of errors codes stored in modules. These error codes are almost never a direct indication of a specific fault, they are simply error *conditions*, usually with many possible causes. This is why it's almost always far less expensive to have problems diagnosed by an experienced technician than to simply throw parts at the car.

A quick google search reveals at least 4 possible causes: https://www.engine-codes.com/p1155_toyota.html

However I wouldn't be surprised if there are other things that could also cause this code to be set. If you bought the sensors from Toyota then the odds are at least the replacement parts you bought are of reasonable quality and probably work, however if they were aftermarket then you can add the possibility of a bad replacement sensor to the list of possible causes.

I would strongly suggest taking the car to someone who knows what they're doing and have them diagnose the problem for you even if you intend to fix it yourself. It could be as simple as a short in the wiring to the sensor.

[flash22]

Codes are used for diagnosis they are a symptom not a cause, i would check the wiring and any corrosion in the plugs, corrosion will play havoc with the resistance

Any corrosion in the fuse box will have a similar effect, you also need to check the voltage to the sensor, and also test with a load to make sure the circuit can carry the current required

[Perfection]

The poster didn't say when the first sensor was replaced, did the fault cleared?  He need to give more info.

[Macscam]

Thank you all for responding,i greatly appreciate your time! I have now admitted  defeat, and the mechanic has my car. Once again thank you for your time.

David