Reading codes
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 801
Likes: 17
From: Middletown Delaware
Reading codes
When checking codes on friends 91 vette the engine fan comes on when jumping aldl connector pin a-b. The ses light works normal but engine fans run the whole time jumper is installed. Also my scanner will only stay linked for a few seconds.
Oil Producer
Joined: Apr 2014
Posts: 9,365
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Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Interesting. I assume this would be the case for a 1990 base?? When I jump the terminals I don't notice the fans coming on. Does this indicate a problem? I know the fans come on when they need to while driving and idle.
Wade
Wade
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Not necessarily. If you were having trouble with ecm turning on fan(s); typically with a/c or dual fans. There is also a temp switch to turn on cooling fan which applies ground to cooling fan relay. Using field service mode you can back probe ecm controlled relay or solenoid to see if it is recieving signal to turn on.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 801
Likes: 17
From: Middletown Delaware
Cornwell scanner 3499. Scanner only stays linked for about 10 sec. Will link again but only for a short time. I tested unit on my 04 truck and it worked fine. Have a snapon MT2500 on the way.
