Fox T-Bird/Cougar Forums

Technical => Electrical Tech => Topic started by: mpd86 on December 17, 2005, 10:53:17 AM

Title: PCM not sending codes
Post by: mpd86 on December 17, 2005, 10:53:17 AM
My car is a 1986 cougar with a 3.8L CFI. Really bad idle problem. Good fuel pressure. Replaced fouled plugs and spark plug wires. Still very rich. Cannot pull any codes from PCM or even communicate with PCM.

Can the car run with a bad PCM ?
Title: PCM not sending codes
Post by: CougarSE on December 18, 2005, 10:18:01 AM
I'm not sure if fords can but I know those  camaros and most other gm's can.  The computer goes into limp home mode but never comes out.  If you can find a spare computer just try it.
Title: PCM not sending codes
Post by: softtouch on December 19, 2005, 11:47:00 PM
When you put the ignition switch in run but don't start, does the fuel pump run for one second and shut off? Thats how it should work.
If the pump continues to run, that may indicate you are in Limited Output Strategy (LOS) mode or "limp home mode". This means the software program in the EEC is not running.