Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

Primary fan turns on when turn key on

Thread Tools
 
Search this Thread
 
Old 05-22-2013, 04:00 PM
  #1  
Member

Thread Starter
iTrader: (4)
 
djmarch's Avatar
 
Join Date: Nov 2003
Location: Virginia
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
Car: 1989 GTA
Engine: 5.7 ltr.
Transmission: 700R4
Axle/Gears: 3:27 9 Bolt Borg Warner
Primary fan turns on when turn key on

Noticed today I heard my driver's side coolant fan turn on when I turned the ignition to the on position before cranking. Started engine and immediately got SES light. So I got my scanner out and hooked her up to the OBD port. It gave me a reading "unable to detect source"..Then tried the paper clip routine and was unable to to get the display to flash at all.

Anybody out there have any ideas on what may happened here ? Did my ECM take a dump ?

Thanks in advance....
Old 05-22-2013, 04:03 PM
  #2  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Primary fan turns on when turn key on

sounds like a bad ecm or the memcal not being seated.
Old 05-23-2013, 03:07 PM
  #3  
Member

Thread Starter
iTrader: (4)
 
djmarch's Avatar
 
Join Date: Nov 2003
Location: Virginia
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
Car: 1989 GTA
Engine: 5.7 ltr.
Transmission: 700R4
Axle/Gears: 3:27 9 Bolt Borg Warner
Re: Primary fan turns on when turn key on

Originally Posted by Tuned Performance
sounds like a bad ecm or the memcal not being seated.
Well I have another ECM I keep as a spare. I can't imagine how the memcal would become unseated. Anyway I have completely rebuilt the top end replacing every sensor and switch. Was running good until then.
Old 05-23-2013, 03:12 PM
  #4  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Primary fan turns on when turn key on

Double check the ground behind the cylinder head , but it sounds like your in limp home mode.
Old 05-23-2013, 03:16 PM
  #5  
Member

Thread Starter
iTrader: (4)
 
djmarch's Avatar
 
Join Date: Nov 2003
Location: Virginia
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
Car: 1989 GTA
Engine: 5.7 ltr.
Transmission: 700R4
Axle/Gears: 3:27 9 Bolt Borg Warner
Re: Primary fan turns on when turn key on

Originally Posted by Tuned Performance
Double check the ground behind the cylinder head , but it sounds like your in limp home mode.
Thanks for the quick reply...And yes I did. I checked both heads where the grounds are bundled and bolted to the rear of them. I could not find no loose wires. Is there a ground coming off the ECM under the dash ?
Old 05-23-2013, 03:31 PM
  #6  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Primary fan turns on when turn key on

There are a total of four grounds for the 165 ecm and all connect to the back of the cylinder head. If I remember correct one is the o2 ground, injector ground , ecm ground and tps, cts, mat ground. no difference with the spare ecm ?
Old 05-23-2013, 03:38 PM
  #7  
Member

Thread Starter
iTrader: (4)
 
djmarch's Avatar
 
Join Date: Nov 2003
Location: Virginia
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
Car: 1989 GTA
Engine: 5.7 ltr.
Transmission: 700R4
Axle/Gears: 3:27 9 Bolt Borg Warner
Re: Primary fan turns on when turn key on

Originally Posted by Tuned Performance
There are a total of four grounds for the 165 ecm and all connect to the back of the cylinder head. If I remember correct one is the o2 ground, injector ground , ecm ground and tps, cts, mat ground. no difference with the spare ecm ?
No, it just acted up a couple of days ago and I haven't had a chance to swap it out yet. I'll be out of town this weekend visiting my son so this weekend is gone. Other symptoms I'm having is idle at 1100 rpms. Other than that, WOT at the throttle body by hand runs smooth. But not able to read the ECM tells me it's gotta be that.

Thanks for your time.
Old 05-23-2013, 03:47 PM
  #8  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Primary fan turns on when turn key on

That and the no ecm communication sounds like it went out to lunch.
Old 05-23-2013, 03:58 PM
  #9  
Member

Thread Starter
iTrader: (4)
 
djmarch's Avatar
 
Join Date: Nov 2003
Location: Virginia
Posts: 260
Likes: 0
Received 0 Likes on 0 Posts
Car: 1989 GTA
Engine: 5.7 ltr.
Transmission: 700R4
Axle/Gears: 3:27 9 Bolt Borg Warner
Re: Primary fan turns on when turn key on

Originally Posted by Tuned Performance
That and the no ecm communication sounds like it went out to lunch.
Yea...The thing of it is, the spare ECM I have with the same broadcast # on the prom is used as well....Bought off of Feebay.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TheExaminer
Tech / General Engine
10
08-19-2015 10:07 PM
Bryan F
Tech / General Engine
2
08-18-2015 02:28 PM
tnrednneck
Electronics
2
08-13-2015 08:57 AM
ZsTransAm
Electronics
1
08-11-2015 07:30 PM
Kaweh
TBI
3
08-09-2015 02:54 PM



Quick Reply: Primary fan turns on when turn key on



All times are GMT -5. The time now is 05:44 PM.