Hey guys, just recently went through the horrible process of replacing my heater core which insisted of removing the dash, a bunch of wire connectors, intake manifold, etc. After getting what i thought was everything together im having some issues when cel and srs light and im thinking its a grounding issue! im not entirely sure how the wiring for the srs system works but im 99% sure i got all the plugs put back where they go. i also have a check engine light for low voltage to intake air temp sensor and another code for my idle air control valve. when testing the wires for the intake air temp sensor im not getting a ground signal at all! i know for a fact this sensor is grounded from the ecu. im assuming whatever possible ground im missing is the same reason for the idle air control valve code and maybe even the srs light. i know the ecu has one ground on the intake manifold and thats got a good connection but im thinking maybe theres another one i missed possibly in the dash area since thats the only other area i was working in. i tried finding a detailed ecu ground diagram but couldnt find anything that would help.

 

Looks like A10 and A23 are your PGs for the ecm. Trying to find if there another connection other than the intake. Above the OBD2 looks like

 

update the srs light just needed to be reset from removing the srs plugs when removing the dash so thats fixed! as for the intake air temp sensor i got a new sensor and it didnt change anything. when checking for ground and 5 vref on the wires both are reading positive voltage. neither wire is ground what so every. the idle air control valve however the wires both test fine one to ground and the other 5 vref so that one may actually just but the iacv.

 

i see a couple grounds above the obd2 but all are grounded i dont see any that i missed

 

The only issue you have now is the idle air control?

 

both idle air control and intake air temp sensor. the idle air control i believe may actually just be the iacv itself because when testing the wires i get a proper 5vref and ground. the intake air temp on the other hand i replaced the sensor and that didnt help, when testing the wires neither wire is getting proper ground and boths wires are actually getting positive voltage one wire getting around 10v and the other around 12v. my understanding is one wire should be a 5 volt reference and the other grounded from ecu.

 

Yo in had your battery cables connected while doing the work?

 

tbh its possible i wasnt doing all the work by myself i had a buddy helping me so between the two of us im sure something stupid like that got overlooked. i know by the end of it the battery was disconnected but whos to say my buddy didnt forget and then unplug it later lmfao

 

BUT unplugging and plugging in the intake air temp sensor with the battery connected shouldnt have caused any damage to the ecu i mean its a relatively small circuit and its my only weird wiring issue i have if i ****ed something up in the ecu id be getting weird **** all over i feel like.

 

Ground should be coming from G101. On the driver side of the engine next to the brake fluid reservoir. Are you getting ground at the ecm