color me dyslexic, code 32 NOT 23

[kenh]

I've had an intermittent check engine light and it flashes code 23 (low intake air temp) I found the hot air snorkel was removed because the engine has headers. Also the port on the air cleaner had the blend door removed and the hole blocked off with duct tape (the aluminum type ment for household use). The only thing left was part of the blend door actuator.

I could find no trace of any type of temp sensor on the air cleaner housing. Where might this sensor be located?

I removed the duct tape in hopes a little engine heat may make some difference. IIRC isn't the ECM "calibrated" for about 100F air????? for best overall performance/drivability???

Ken

 

[PlayingWithTBI]

What year truck and ECM?

 

[kenh]

1990, 350 engine, Dont know the ECM year but thinking it is also 1990. I'm the third owner of the truck. First owner had it for 25 years. Supposed to be stock except for headers on the engine installed by the previous owner.

Ken

 

[df2x4]

I'm not much help as I'm not very familiar with the TBI trucks, but if you haven't already you might check the 1990 GM factory service manual. You can find them for free in PDF format here.

https://www.gmt400.com/threads/88-95-service-manuals.43575/

 

[PlayingWithTBI]

The reason I asked is the early TBIs don't have a MAT (Manifold Air Temp) sensor and the .bin doesn't have that MALF code checked so it shouldn't show a code 23. Odds are, you have a 1227747 ECM, it's behind the glove box on the right. I looked at a few .bins for a 7747 and none of them are set for MAT codes. Maybe someone's been playing with their calibration?

You must be registered for see images attach

 

[Schurkey]

Clear the code, see if it comes back.

Connect a scan tool, see what codes register, and what the data stream shows.

 

[kenh]

OOOOH! Thanks for the link to the service manual!! Will be very handy! The Check engine light is on all the time now. I'll have to buy a scan tool as I don't have one. In the meantime I'll pull the battery cable and see what happens.

Do the better Blue tooth tools work OK? Would be nice to have something I can use on our Subaru Legacy if the need arises.
https://www.amazon.com/BAFX-Products-Reader-Diagnostics-Devices/dp/B078K54MT5
Sent an email to see it this would work on OBD-1 vehicles with an adapter.

Ken

 

[df2x4]

I don't believe any of the Bluetooth modules are compatible with OBD1 vehicles unfortunately, at least I've never seen one that was.

 

[evilunclegrimace]

Code 23 is for MAT on a 2.5 4 Cylinder engine

 

[Busted Knuckle]

I've had an intermittent check engine light and it flashes code 23 (low intake air temp) I found the hot air snorkel was removed because the engine has headers. Also the port on the air cleaner had the blend door removed and the hole blocked off with duct tape (the aluminum type ment for household use). The only thing left was part of the blend door actuator.

I could find no trace of any type of temp sensor on the air cleaner housing. Where might this sensor be located?

I removed the duct tape in hopes a little engine heat may make some difference. IIRC isn't the ECM "calibrated" for about 100F air????? for best overall performance/drivability???

Ken

You should be able to replace the AIT sensor with a resistor to ground. You'll have to do some research to find the correct value. Pick a value that sets the temp to 90F (or whatever) would be an expected value. See if you can search the sensor number and get an output curve.