P0689 code

[lestarge89]

P0689 code can anyone help???

anyone know how to fix this code (P0689 ecm/pcm power relay sense circuit low) i can erase the memory and as soon as i turn the key off and back on its there again. i talked to ford they have no clue its a 05 mustang gt anyone have this code b4????

 

[Black Tooth Grin]

Try checking fuse #45 in the power distribution box.

 

[lestarge89]

Try checking fuse #45 in the power distribution box.

fuse was good checked and replaced even tho it showed good still the same thing turn key on and code was there cleared code then turn key off and then on code was back

 

[ixtlan]

This DTC sets when the ignition switch position run (ISP-R) circuit indicates the key is in
the OFF, ACC, or LOCK position, and the amount of time the PCM remains powered
through the PCM power relay exceeds a predetermined amount of time.

Possible
Causes:

PCM relay control (PCMRC) circuit short to ground in the harness

Damaged PCM power relay

Thats from the manual.
Sounds like a bad relay or a ground for the relay perhaps.
I would go for the relay ground first.

 

[lestarge89]

This DTC sets when the ignition switch position run (ISP-R) circuit indicates the key is in
the OFF, ACC, or LOCK position, and the amount of time the PCM remains powered
through the PCM power relay exceeds a predetermined amount of time.

Possible
Causes:

PCM relay control (PCMRC) circuit short to ground in the harness

Damaged PCM power relay

Thats from the manual.
Sounds like a bad relay or a ground for the relay perhaps.
I would go for the relay ground first.

do u know where the relay ground is?

 

[Black Tooth Grin]

It's in the owner's manual. I "think" it is # 23? I might be wrong. Hell, I was guessing at the fuse #45 position also. Just look in the owner's manual for stuff pertaining to the PCM. You should find it.

 

[ixtlan]

I think it is in the group of grounds forward and outboard of the PCM.
R side of engine bay.
Should be marked G103.

 

[lestarge89]

I think it is in the group of grounds forward and outboard of the PCM.
R side of engine bay.
Should be marked G103.

do u have a wire diagram on this i think its the 2 ground wires on the radiator support on passenger side but not for sure

 

[ixtlan]

http://iihs.net/fsm/?dir=40&viewfile=Electronic Engine Controls - 4.6L.pdf

 

[lestarge89]

http://iihs.net/fsm/?dir=40&viewfile=Electronic Engine Controls - 4.6L.pdf

i checked the two ground wire to the body of the car a good ground and only 1 had continunity through it should they both?

 

[G.T]

http://iihs.net/fsm/?dir=40&viewfile=Electronic Engine Controls - 4.6L.pdf

beat me to it
glad you guys are making use of this!

 

[ixtlan]

Both
Clean them up good and check for breaks or chaffing

 

[ixtlan]

beat me to it
glad you guys are making use of this!

You are awesome for putting that up!
Rep Point for sure!!!

 

[lestarge89]

cleaned grounds and still the same problem even tried switching relay

 

[ixtlan]

I would suggest looking real close for chaffed wires and broken wires.
Did you get continuity through both grounds?
Since after clearing the code it returns there must be an intermittent break somewhere.
I am assuming (hate that) you cleared the code.
If not it will keep popping up until you do.
As far as chaffing look real close around where the wires come from the relay box.
They stuffed a lot through pretty tight holes.

 

[05stroker]

You ever figure this out? I'm fighting a p0689!

 

[Wild White Pony]

Do you know if your car is staying in closed loop, I know I've been fighting this code after a trans swap and noticed that the car would startup open loop, close for a brief moment and then go back into open loop. My emissions would never set because of the open loop however my car runs fine, just have to tweak open loop A/F settings. Been this way for the last 2 years, getting back to working out this problem this spring. Figure I'll get a 2006 manual engine harness and install before tracing all this out.