How hot should the ECM get? Did I fry my TT Chip

[gidyuppp]

How hot should the ECM get after idle at 10 mins. History: Car running fine, turned it off in drive way and would not start (cranked by nothing). No MAL codes on scan master TPS was a little high but that was adjusted with no change. Changed the ignition module/coil pack. CAr turned over but idling rough and stalling in gear. Wire confirmed correct on the module to coil pack. Crank sensor installed this morning with no change. Hooked car up to Modis Snap on diagnostic tool and no codes. Set the car in back up mode and it smoothed out the idle when out of that mode rough idle again. Diagnostic tool stated ECM possible cause. Took ECM out and it was very hot for only running 10 mins. How hot should these things be? Never had it out before. Could it fry the TT 93 octane chip? Thanks

 

[kidglok]

im gonna go out on a limb here and suggest the cam sensor, is it set within the window? Try rotating it a little counter clockwise and see if it clears up.

 

[gidyuppp]

Thanks. Its locked up at my buddies shop but we will give that a try in the morning. I will post back.

 

[gidyuppp]

Update. Cam sensor rotated within window and still rough idle. Found an ECM and plugged that in and this one does not even get warm, so there must have been an issue with my old ECM to get that hot. Did that heat short something out? I just ordered a new TT chip just in case it got too hot in the ECM and messed it up but not sure that will be the answer. Car is still not throwing any codes on Scantool and Modis diagnostic. Injectors were pulled and all are functioning.

 

[kidglok]

maybe something shorted in the ecm and thats why its getting hot.

did you try your current chip in the other ecm when you tested it?

 

[gidyuppp]

Yes, the car ran the same. So I am hopeful a fresh chip will do it. Thanks

 

[ijames]

The stock ecm with high impedance injectors will get a little warm but shouldn't get hot. One modifed with peak and hold drivers for low impedance injectors will get somewhere between very warm and hot (hottest at wot) but not so hot you can't keep your hand on it indefinitely.

 

[gidyuppp]

The stock ecm with high impedance injectors will get a little warm but shouldn't get hot. One modifed with peak and hold drivers for low impedance injectors will get somewhere between very warm and hot (hottest at wot) but not so hot you can't keep your hand on it indefinitely.

New ECM, New Chip same rough idle. I had a spare cam sensor and installed that. Still rough idle. When I initially had an issue with my module it got so hot that it melted a GN emblem for the coil pack and also got so hot it melted the plastic clip for the heat pad on the hood. Do I need to pull the wiring harness to check for something as simple as a short? Could the heat have damaged a wire near the module? Darn car has a new crank sensor, cam sensor, plugs, coil pack and module and still idles horrible.

 

[Daniel Jost]

When you say in "Backup Mode" what do you mean? Are you talking about open loop or limp home mode? How does the reading from the MAF look? It also puts the car into Batch fire fueling in Limp home mode so I wonder if your fuel is injecting wrong... Have you tried pulling the Up pipe and spraying fuel in and trying to run it like that to see if it runs better?

,Dan

 

[Blazer406]

Does the car have the correct FP?

You could with the car running...... disconnect the cam sensor.... this will force it out of sequential mode. If the idle all-of-a-sudden clears up..... it is a cam sensor or wiring issue to/from the cam sensor.

 

[gidyuppp]

Does the car have the correct FP?

You could with the car running...... disconnect the cam sensor.... this will force it out of sequential mode. If the idle all-of-a-sudden clears up..... it is a cam sensor or wiring issue to/from the cam sensor.

Got a call from the local GN expert here in Michigan and I feel dumb. The initial problem I changed with the module turned out to ne a defective new module. I guess I assumed a new part wouldn't be an issue. Thanks to everyone for the suggestion. I learned a ton more about these cars with this issue.