Code 24 IAT Sensor Signal - Help?

[Rich.2211]

I have just fitted a replacement NA engine to my Supra and all has gone pretty smoothly apart from the large warning triangle is now illuminated in the center of the rev counter and when I read the fault codes it is throwing up 24 (Intake Air Temp, Sensor Signal). I am using my original ECU (1994 NA Manual 5spd) with the engine and loom from a later model 6spd Supra.

 

Trouble areas according to the manual are:

 

- Open or short in intake air temp, sensor circuit

- ECU

- Intake air temp, sensor

 

My intake air temp sensor was fine on the last engine. The car drives perfectly. Is code 24 actually meant to throw up the large warning triangle? My only other query is with the new engine being from a facelift or more modern Supra is there some problem/difference with using my earlier ECU that I should be aware of?

 

Lastly.. I'm 99.99% sure I'm not being a retard and it's actually flagging up code 42 aka the oh so common speed sensor code that Supras like to throw up (which would explain the large red triangle).

[Chris Wilson]

Carefully measure the resistance across the contacts in the ecu *PLUG* that go to the IAT. Don't force probes in and bend the contacts, use thin solid core wire, or thick needles.

[Rich.2211]

Cheers for the advice Chris.

 

All sorted now though. Turned out the air intake temp sensor was faulty, so has been replaced, and the large warning light was on because facelift engines don't have the electronic oil level sensor that the prefacelift cars like mine had - hence it thought it had low oil level and chucked the light on.