AFTER EVAPORATOR REPLACEMENT, CAR CAN'T START, NO IGNITION LIGHT ON DASHBOARD

#3

Total dash disassembly to do the evaporator replacement = very high probability of leaving something disconnected or not fully connected.

 

We just did the same thing! We got everything put all back together after swapping an evaporator from a parts car....and no start. We had headlights, brake lights, interior dome lights, but just nothing ignition, or dash display wise. It turned out we forgot to swap out the immobilizer ECU on the back side of the blower housing. We left the immobilizer ECU from the parts car on, never even thinking twice about it. Once we replaced to the correct ECU for the car, it started. One quick suggestion; if possible use Techstream with obd2 scanner and scan for the issue. It should get you closer to figuring out where the issue is. It was so frustrating for us DIY mechanics.

 

Can you type step by step exactly how you got this ECU immobilizer problem fixed? I have the same issue after changing the expansion valve disassembling the entire dash. All the lights, radio, fan etc work but car won't start and there's no codes to clear. Batteries are new. It must be this ECU immobilizer thing you solved.

 

When used parts from a salvage car. They accidently installed the immobilizer ecu from the salvage car into their car. This won't work, as each immobilizer is programmed for the specific car. They went back in and installed the original immobilizer ecu and the car was good to go.

Some ecus can be swapped between cars with no programming required. For instance, the Transmission Control Module or the HV Battery ecu. The immobilizer ecu is NOT one of those that can be swapped with no additional action required.

 

Thanks for the reply! I'm currently sore, in pain from 3 days of labor. Was that person you under different name? How do you "accidentally" install a wrong part after specifically swapping the evaporator core? From my experience the ECU immobilizer is located under the air blower where the glovebox is on the front passenger side, you don't even need to take it out to access the core, maybe just unplug it and leave it on the floor like I did being a first timer who unplugged everything to locate the expansion valve since there's no instructions anywhere I can find. I'm just confused how you "accidentally" plug the wrong ECU immobilizer after swapping the core, was it just laying around everywhere?

 

maybe I'm wrong about the location of the immobilizer ECU, they look like the material I plugged under the blower. I guess I'll have to pull out everything again. It's not that difficult anymore because I don't have to unscrew the metal bar, that was the hardest part. The first time is always the toughest now I feel confident I can do this again. I just need to rest, I'm sore as hell.

 

It sounds like they swapped the entire HVAC housing from a donor vehicle, instead of disassembling the original and replacing just the evaporator.

 

That makes sense.

Update: so it's amazing how things change overnight, I went from having a car to no car in just 2 days, I woke up with more white hair from stress this morning than prior & started contemplating about all the sins I did & how I deserve this . So I opened the entire thing again, traced all the wires for the 3rd time, and guarantee I didn't miss reconnecting anything just to get that out of the way. The benefit of the smartphone is it can act as a second person. Since everything works but no start I figured it has something to do with the brakes. I used my smartphone to record and see if the brake lights work, nope, not working. Check fuse 9 under the steering wheel and it's fine. So I checked the brake switch light and it was bent. I knew this was the problem. I smashed it when I pulled the bar out. Car is running again but it taught me a lesson, I need a spare car.... I bought a good running van yesterday for $1000 it's not possible to ride my bike around town man plus my side chick lives 160 miles away..... Yeah yeah yeah I'm a sinner, Lord send me the grace to be righteous. I nearly swapped the ECU immobilizer, that would have been extremely stupid because my programmed keys would need to be reprogrammed too... I'm good... Have a nice day everyone and remember, you need a spare car....

Peace...