ecm in limp home mode& code23 help please!!
 

Ok today i checked my 89 gta 5.7 on a scantool and the outcome was this. code 23, is MAT/ -40DEGF.the tool also said that the ecm is in LHM. would this cause the ecm to be in limp home mode or do i have a bad ecm?any help would be great! thanks in advance


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89 gta 5.7 to many mods to list 89 formula 5.0 tbi (commuter)

GTA,

That means the MAT/IAT has either failed or is disconnected. It is located on the underside of the intake plenum. The sensor is about ten bucks. Before you get all wrench-happy to replace the MAT sensor, read this article:

MAT/IAT Sensor.pdf

You'll need Adobe Acrobat Reader to open/view/print the file (see below).

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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader

vader, i replaced the MAT sensor yesterday. and i'm still getting a code 23 . i have a 52 mm holley tb and a ported plenum the same size. do you think thats causing the code. and if so do i need to move the MAT sensor?thanks for repling https://www.thirdgen.org/messgboard/smile.gif


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89 gta 5.7 to many mods to list 89 formula 5.0 tbi (commuter)