Computer Diagnostics and Tuning Technical discussion on diagnostics and programming of the F-body computers

1995 Camaro Z28 DTC 42 / 68 / 70

Old Jan 24, 2025 | 03:34 PM
  #1  
Mnp40c's Avatar
Thread Starter
Registered User
 
Joined: Jan 2025
Posts: 13
1995 Camaro Z28 DTC 42 / 68 / 70

Hey all! Finally got Gary’s program working and pulled the DTCs from my 95 Z28. Can anyone point me in the right direction. I am getting error codes seen below. For error 42 I found some info in other forums but still not sure where to start.

As far as the other 2 codes, my mechanic recently put in an Accel distributor cap and rotor kit, and also replaced the A/C compressor and recharged system. Did they miss something? NOTE: Car appears to run just fine.

My Camaro was not driven much for 10 years and only has 52,900 miles on it. I have done all the required maintenance to bring it back to life and then some. Just want to get rid of these pesky codes.

Thanks in advance!


Old Jan 24, 2025 | 08:20 PM
  #2  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Re: 1995 Camaro Z28 DTC 42 / 68 / 70

If the engine is running “just fine”, use Scan9495 to clear the codes and see if they come back. The AC stuff is probably legit, but may have been set before the AC repairs. Does the AC work correctly?

To learn more about the codes, what causes them to set, and a logic tree for diagnosing the cause(s), download (free, and offered by GaryDoug) the 1995 factory service manual.

https://www.mediafire.com/?40mfgeoe4ctti
Old Jan 25, 2025 | 04:54 AM
  #3  
Mnp40c's Avatar
Thread Starter
Registered User
 
Joined: Jan 2025
Posts: 13
Re: 1995 Camaro Z28 DTC 42 / 68 / 70

Originally Posted by Injuneer
If the engine is running “just fine”, use Scan9495 to clear the codes and see if they come back. The AC stuff is probably legit, but may have been set before the AC repairs. Does the AC work correctly?

To learn more about the codes, what causes them to set, and a logic tree for diagnosing the cause(s), download (free, and offered by GaryDoug) the 1995 factory service manual.

https://www.mediafire.com/?40mfgeoe4ctti
Thank you for the info and manual! It’s pretty snowy here in Michigan so I haven’t taken it on the road lately, but I did clear the codes and the check engine light goes out for about 5 seconds then comes right back on with error code 42. So far the A/C codes have not reappeared but haven’t really run the car long enough to see if they will show up again. I bought a new ICM for only $20 bux on Amazon that had good reviews so may just try replacing it to see what happens but I’ll hold onto the old one just in case.
Old Jan 25, 2025 | 08:56 AM
  #4  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,098
From: Hell was full so they sent me to NJ
Re: 1995 Camaro Z28 DTC 42 / 68 / 70

Does the engine start? If so, does it idle smoothly?

Here's a link to testing the ICM circuitry - 12 volt power and ground:

4th Gen LT1 F-body Tech Articles

Focus on ICM harness circuitry.
Old Jan 26, 2025 | 04:26 PM
  #5  
Mnp40c's Avatar
Thread Starter
Registered User
 
Joined: Jan 2025
Posts: 13
Re: 1995 Camaro Z28 DTC 42 / 68 / 70

Just to follow up, I replaced the ICM and cleaned the connector, and by some miracle it cleared the code! Took the car out for a half hour drive and so far no check engine light! Thanks for your help!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Phil Peterson
Drivetrain
3
Jul 20, 2022 08:35 PM
BLUETOPTA
Midwest
7
Aug 3, 2006 09:41 PM
v-8
Computer Diagnostics and Tuning
7
Jun 10, 2006 06:08 PM
Fred Jeter
LT1 Based Engine Tech
1
Oct 16, 2003 07:27 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 03:47 AM.