p1155 and p1135

[ozzyboy]

2.0 petrol 2002 model

how likely is it to get these two faults together and could it be something else apart from replacing both sensors

 

thanks in advance

[pmb]

Never heard of 2 alarming at the same time but this fault is very common on the petrol engines. I've had 3 or 4 replaced over 16 years of ownership. The heater circuit goes open circuit and causes the light to come on. Sometimes I found that resetting the code would clear it for so long. The heater circuit is the black wires if you want to measure the resistance between them.

[ozzyboy]

will do....they wont clear ive tried several times...thats why i thought it might be a fuse or relay

 

[gjnorthall]

It would be unusual but not impossible for the heaters on both inlet sensors to fail together. It’s also unusual to be unable to clear the codes - have you attempted this by disconnecting the Battery rather than using the delete feature on your code reader?. The way the system works is that the ECU checks the heater resistance on a sequence and in the event of a fault will first record a pending code and if the fault is still present at the next check, the system will illuminate the engine light. Once deleted, it may take 5 miles or more of driving for the code to reappear and trigger the engine light. In the first instance, check for an open circuit across the heater coils which would confirm heater coil failure. To eliminate any fuse or bad connection issues, with the ignition on, check that you have 12v going to both heaters.

[bonjo]

I have had 2 repalced over the years. In both instances it was the sensor ( heater circuit I think) and they were banks 1&2 sensors 1. I only managed to check the fuse which was good.

In my case a code reader cleared the fault only for it to reappear after a while so it was a sensor change.

I have no suggestions as to why you get two faults but looking at my experience if the codes relate to sensors 1 then it is possible they have both failed