Hello guys I've had a search but cannot find the info i need to check the wiring from IAT to the ECU 

I have code po113.... IAT sensor high input,

 

I have replaced the MAP/IAT sensor and checked freeze frame data and the temp is stuck on -40 c,

 

I have checked the wiring plug at the sensor and checked the wiring for voltage and continuity 

at pins 3+4.I have +5v ref

..pin 2 signal wire continuity shows zero ohm  but volts read +2v

pin 1 earth pin shows 12 ohm resistance

 

I don't think pins 1 and 2 are reading correct so I need to check contiuity back to the ecu but i need the pin numbers and wire colours.

 

Any help appreciated. 

Wiring diagrams are segmented by engine code, so furnish me with that and Ill try to help.

It'll appear on the build sticker on the boot floor, and possibly also in the service book.

Thanks for the quick reply engine code from service book...CAYC.

Pin 2 ends up at engine ECU pin 30 as a white wire, changing from yellow at pin 7 of an 8-way connector 'front left of engine bay'.

Pin 1, brown at IAT turns to brown/blue at pin 8 of same connector and ends up at pin 79 of engine ECU (which also connects to the 'pressure differential sensor'.) 

Left/right are as seen sitting in the car facing forwards.

19 minutes ago, Wino said:

Pin 2 ends up at engine ECU pin 30 as a white wire, changing from yellow at pin 7 of an 8-way connector 'front left of engine bay'.

Pin 1, brown at IAT turns to brown/blue at pin 8 of same connector and ends up at pin 79 of engine ECU (which also connects to the 'pressure differential sensor'.) 

Left/right are as seen sitting in the car facing forwards.

Thanks for the info, Do you know the location of the 8 way connector on the LHS  I imagine it is under the battery or airbox with easy access and hopefully that may be where the issue is,

I can do continuity tests back to the ECU from there hopefully.

Not a clue, sorry.

Just now, Wino said:

Not a clue, sorry.

OK thanks I'll get a look in a few days,  I'll report back when i get answers.

On 29/07/2020 at 20:07, Wino said:

Pin 2 ends up at engine ECU pin 30 as a white wire, changing from yellow at pin 7 of an 8-way connector 'front left of engine bay'.

Pin 1, brown at IAT turns to brown/blue at pin 8 of same connector and ends up at pin 79 of engine ECU (which also connects to the 'pressure differential sensor'.) 

Left/right are as seen sitting in the car facing forwards.

Hi I think i have confused the pin termination points, please could you give me the termination points for pins 3 and 4 also, my readings don't appear to tally with the expected values i should be getting.

Thanks Alan.

Pin 3, white at sensor connector, turns to red/green at pin 6 of the 8 way plug/skt connection, originating from pin 14 of engine ECU (which also feeds 5V to the pressure diff sensor)

Pin 4, green wire at sensor, becomes black/yellow at pin 5 of 8-way, ending up at ECU pin 83.

Thanks for the info, I'll have another look at it.

Thanks for the info, I'll have another look at it.

UPDATE.. I got the car on the ramps today and dropped the undertray to change the oil and filter and check the wiring to the IAT sensor, the wiring at the sensor was ok so checked the wiring at the 8 way connector which is easy to see, it's mounted in front of the gearbox behind the intercooler pipe, the white wire and the brown/blue on the ECU side of the connector had been chafing on the edge of the hard plastic sheathing  on the wires and the whit wire broke when i touched it the brown/blue was also damaged, these are the 2 wires from the IAT sensor so it looked like i had found the fault.

both wires were corroded and had to be trimmed back an inch or so from the connector so i decided to bypass the connector.

I added approx 100mm to each wire soldered and shrink wrapped then taped the sheathing back over the wires to prevent more damage and a few tie wraps and the job is sound,  and best part is the fault codes are gone.

I took a few pics.