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Jerry Newton
Jerry Newton, Chevy Technician
Category: Chevy
Satisfied Customers: 4412
Experience:  ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.
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2005 chevy Colorado acts like its shutting off and

Customer Question

2005 chevy Colorado acts like its shutting off and restarting when on highway tack drops below 1000 and heat gage drops to 0 than it will go back up in power and the gage goes back to operating temp
Submitted: 1 year ago.
Category: Chevy
Expert:  Jerry Newton replied 1 year ago.

This sounds like the engine control computer is shutting down for some reason. I would start by looking at the easy things, like a loose battery cable, any wiring damage under the hood (think field mice or other rodent, they like to get in there and chew on wires sometimes), etc. Sometimes just a good visual inspection can reveal the root of a problem like this.

How often does it happen? If you can replicate it reliably, a mechanic may be able to attach a good scan tool and see what's going on, to at least point in the right direction if the visual inspection doesn't turn anything up.

Customer: replied 1 year ago.
the above has all been done even the throttle body has been cleaned it seem to have gotten worse it even shut off when stoped at a light
Expert:  Jerry Newton replied 1 year ago.

OK.

There's not much question about the fact that the ECM is shutting down. The giveaway on this is the temp gauge. Data for the temp gauge comes from the ECM, so if the ECM stops communicating, the temp gauges drops to cold.

I would be checking the power and ground circuits to the ECM, using a multimeter to monitor those voltages while driving it (replicate the problem and see if the voltage or ground is going away). If power and ground stays consistent when this acts up, it's probably going to be a faulty ECM.

ECM must be programmed, they come with no software when you purchase from the dealer. For this reason, you may want to have your dealer get a look at this, confirm the diagnosis, and then if necessary, replace and program the ECM.