ECM Problem

Tiny
CNASR
  • MEMBER
  • 2005 CADILLAC CTS
  • 3.6L
  • V6
  • RWD
  • AUTOMATIC
  • 300,000 MILES
After replacing a damaged battery, I got some troubles with my car. While driving, the fuel appears not injected properly or a spark (coil) is not working and the check engine light start blinking. This status is not permanent as some times these symptoms disappear.

The mechanic who inspected it told me that the ECM is damaged needing to be replaced.

So what I want to ask you please is there any way to check if it's a hardware problem inside the computer or a program needing to be reset and how to do it?

Appreciating your answer,

Regards & Thanks.

Chady
Friday, May 29th, 2015 AT 11:52 PM

4 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
It is tough tell run tests on the ECM to see if it is bad most just replace it here are the instructions and diagrams below.

1. Turn the ignition OFF.
2. Using a scan tool, retrieve the percentage of remaining engine oil and the remaining automatic transmission fluid life. Record the remaining engine oil and the remaining automatic transmission fluid life.

IMPORTANT:
- It is necessary to record the remaining engine oil life. If the replacement module is not programed with the remaining engine oil life, the engine oil life will default to 100%. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5000 km (3,000 mi) from the last engine oil change.
- It is necessary to record the remaining automatic transmission fluid life. If the replacement module is not programed with the remaining automatic transmission fluid life, the automatic transmission fluid life will default to 100%. If the replacement module is not programmed with the remaining automatic transmission fluid life, the automatic transmission fluid will need to be changed at 83000 km (50,000 mi) from the last automatic transmission fluid change.

3. Use a DVOM in order to measure the main relay circuit voltage at the ECM fuse in the underhood fuse block.

IMPORTANT: Ensure that there is no main relay circuit voltage (ECM Fuse).

4. Disconnect the battery negative cable.
5. Remove the ECM fuse in the underhood fuse block.
6. Remove the TCM/IPC fuse in the underhood fuse block.
7. Remove the ECM/TCM fuse in the underhood fuse block.
8. Unlock the chassis side (upper) ECM electrical connector.
1. Depress the ECM electrical connector lever lock (1).
2. Simultaneously rotate the ECM connector clamp lever and depress the lock slide (2).

10. Install the body side (upper) ECM connector.
11. Install the ECM/TCM fuse in the underhood fuse block.
12. Install the TCM/IPC fuse in the underhood fuse block.
13. Install the ECM fuse in the underhood fuse block.
14. Connect the battery negative cable to the battery.
15. Program the ECM. See: Vehicle > Programming and Relearning
16. Turn OFF the ignition for at least 5 seconds after the programming event is complete.

ENGINE CONTROL MODULE PROGRAMMING AND SETUP

The following service procedures require either a programming or a setup event performed for a complete repair.

ECM Replacement
If the engine control module (ECM) is replaced, the following procedures must be performed:
1. ECM Reprogramming-Refer to Service Programming System (SPS).
2. Idle Learn Procedure-Refer to Idle Learn Procedure in Computers and Control Systems - 2.8L (LP1) or Idle Learn Procedure in Computers and Control Systems - 3.6L (LY7).
3. Theft Deterrent-Refer to Programming Theft Deterrent System Components in Theft Deterrent. The ECM will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. An ECM which has been previously installed in another vehicle will have learned the other vehicle's fuel continue password, and will require a learn procedure after programming to learn the current vehicle's password.
4. Engine Oil Life Remaining-When available, use a scan tool to reset the Engine Oil Life Remaining back to the original percentage recorded before the module was replaced.
5. Transmission Fluid Life Remaining-When available, use the scan tool to reset the Transmission Fluid Life Remaining back to the original percentage recorded before the module was replaced.

ECM Reprogramming
- If the engine control module (ECM) needs to be reprogrammed, refer to Service Programming System (SPS).
- Engine Oil Life Remaining-When available, use a scan tool to reset the Engine Oil Life Remaining back to the original percentage recorded before the module was reprogrammed.

Setup for Component Replacement
The replacement of some components will require a setup procedure for complete repair.

If any of the following components are replaced, an Idle Learn Procedure must be performed. Refer to Idle Learn Procedure in Computers and Control Systems - 2.8L (LP1) or Idle Learn Procedure in Computers and Control Systems - 3.6L (LY7).
- Throttle body assembly
- ECM

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
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Saturday, May 30th, 2015 AT 6:15 AM
Tiny
RICKYSH11
  • MEMBER
  • 74 POSTS
  • 2005 CADILLAC CTS
  • 6 CYL
  • 2WD
  • AUTOMATIC
Is it possible to purchase a pre programmed ECM for my CTS without taking it to a dealer?
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Thursday, June 20th, 2019 AT 6:13 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,758 POSTS
Some places can program off the car but most require it be installed in the car.
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Thursday, June 20th, 2019 AT 6:13 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Why don't you try having the computer reflashed and see what happens-might fix all the factory bugs that causes driveabilty problems etc-during the making
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Thursday, June 20th, 2019 AT 6:13 PM (Merged)

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