Check Engine Light + No codes
Thread Starter
Instructor
Joined: Jun 2000
Posts: 183
Likes: 0
From: Olympia WA
Check Engine Light + No codes
Hi Guys,
Long time no see. I have the 81 in the shop right now. They have gone through it and she drives ok and seems to run fine. The check engine light is still on though.
I spoke to the tech and they said that it is not communicating and thus not throwing codes.
Is there anything I should try? Ignore it since it is running, or replace the ECM? Has anyone had a similar issue with some suggestions?
Long time no see. I have the 81 in the shop right now. They have gone through it and she drives ok and seems to run fine. The check engine light is still on though.
I spoke to the tech and they said that it is not communicating and thus not throwing codes.
Is there anything I should try? Ignore it since it is running, or replace the ECM? Has anyone had a similar issue with some suggestions?
Last edited by LuVettes; Aug 26, 2014 at 09:46 AM.
Racer
Joined: Nov 2011
Posts: 319
Likes: 12
From: South Chase WI
Simply unplugging any sensor or the distributor plug will throw the light. Anyone can read the ecm with a jumper wire on these, the CEL will flash the information with a number of blinks and pauses. The plug for checking it is under the ashtray. Plenty of info on here to do it all yourself.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
Any harbor freight has a cheap scan tool. It seems many shops now a days don't have the old ALDL scan tools anymore. They plug their new stuff in and they get nothing. The scan tool is cheap or jump it. It's outlined in the manual but it's sometimes hard to keep track of the number of blinks
Burning Brakes
Joined: Nov 2013
Posts: 889
Likes: 13
From: Jax/St. Augustine FL
I am an 81 owner with a fully functional CCC and I have gone to great lengths to understand the system and keep it operational.
The system is an OBD I (5 or 12 pin ALDL interface = most are 5 pin in the ashtray) - get on ebay and look for an "OTC Monitor 85" it's the original scan tool and is excellent. Search this forum for that verbiage ("OTC Monitor 85") and you will see my post with a video, etc on its use and value. The light can be on with a code but a OBD II is not going to catch it.
until you get that - as previously mentioned jump the pin's and read the blinks. On that same post i have a link for you to conact me to get the full manual of the scan tool that includes the who/what/why of the codes (have to e-mail it - its a huge file)
best of luck
Brian
The system is an OBD I (5 or 12 pin ALDL interface = most are 5 pin in the ashtray) - get on ebay and look for an "OTC Monitor 85" it's the original scan tool and is excellent. Search this forum for that verbiage ("OTC Monitor 85") and you will see my post with a video, etc on its use and value. The light can be on with a code but a OBD II is not going to catch it.
until you get that - as previously mentioned jump the pin's and read the blinks. On that same post i have a link for you to conact me to get the full manual of the scan tool that includes the who/what/why of the codes (have to e-mail it - its a huge file)
best of luck
Brian
