New ECU installed now it will not start

Tiny
KEVIN STINEMATES
  • MEMBER
  • 2011 CHEVROLET EQUINOX
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 116,000 MILES
I have had trouble with my ECU so I bought a replacement unit and installed it. When I turn the key all the lights come on but it wont turn over at all and the check engine light is flashing. Is this possibly because of my keys not being set to the new ECU? The company I bought this ECU from had set it to my VIN number do I still have to do the keys?
Saturday, December 14th, 2019 AT 6:06 PM

7 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

The process for key relearning doesn't involve the ECM. What did the manufacturer tell you? Also, was the car's battery disconnected when the new ECM was installed?

Let me know.
Joe
Was this
answer
helpful?
Yes
No
Saturday, December 14th, 2019 AT 7:34 PM
Tiny
KEVIN STINEMATES
  • MEMBER
  • 3 POSTS
Yes, I disconnected the battery while switching the ECU out. I put the old one back to see if it would work and it did. Do I need to have the new ecu reprogrammed? When I ordered the new ecu I was told this should be a plug and play type of install but when I switched them and turned the key all the normal dash lights came on but it did not do anything else. Just flash the check engine light.
Was this
answer
helpful?
Yes
No
+1
Saturday, December 14th, 2019 AT 7:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
I think you got a faulty part. Is there a theft light flashing?
Was this
answer
helpful?
Yes
No
-2
Saturday, December 14th, 2019 AT 10:32 PM
Tiny
KEVIN STINEMATES
  • MEMBER
  • 3 POSTS
No there isn't a theft light flashing. I did go through the process of trying to see if that might be the problem but it didn’t work either. Thank you for your help. I will have to call the company where I bought the ECU from.
Was this
answer
helpful?
Yes
No
Sunday, December 15th, 2019 AT 2:38 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Let me know what you find. Based on what you are saying, it sounds like that is the problem.

Take care,
Joe
Was this
answer
helpful?
Yes
No
-2
Sunday, December 15th, 2019 AT 5:19 PM
Tiny
GDZANML
  • MEMBER
  • 1 POST
Did you ever figure this out? I’ve gone through three replacement ECMs, so it’s got to be something else. I’ve done the relearn a bunch of times just in case, to no avail.
Was this
answer
helpful?
Yes
No
Friday, June 10th, 2022 AT 9:08 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

I'm sorry, but he never replied back. Exactly what is happening?

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Saturday, June 11th, 2022 AT 7:00 PM

Please login or register to post a reply.

Related Engine Not Running Content

Car Cranking but Not Starting? Try This
VIDEO
Car Cranking but Not Starting? Try This
Instructional repair video
Engine Not Starting
GUIDE
Engine Not Starting
Over the past 20 years at 2CarPros we have identified the top problems that are easily fixed. This guide can save you a trip to the repair garage or calling a tow truck and...
VIEW MORE