P0689 code when on a steep hill

[LawrenceF]

OK, I got a P0689 ECM/PCM Power Relay Sense Circuit Low code set when I filled up at a garage near me and stopeped on the steep exit from there.
It's now done it 3 times now, so I'm guessing I have a bust wire or a plug hanging out. Are there any under dash connections that power the PCM?
(it's had an alarm stuck in badly before I got it, and it wouldn't surprise me if it had damaged the under dash wiring). Could also be the source
of my cold stumble too if it's got a poor connection on ign+.

[maxmc2]

I had this exact same cade as Richard kindly diagnosed for me yesterday.

It turns out that as a resuly of my car being left for months on end the battery sends a signal to the ECM/PCM to notify it of low voltage, so in my case not something to worry about.

But if yours does it quite often i would suggest checking wiring around battery and ECM/PCM and fuses, not sure what that could be, sure someone will be able to assist further.

[MadMaxHSV]

Not one to worry about. I get the 689 code quite a lot.
You might get it more if your battery is a little weak or if your running some extra accessories. I'm running a few wideband controllers off an accessory circuit which throws codes when i've got a lot switched on.

[MyM8V8]

MadMaxHSV said:

Not one to worry about. I get the 689 code quite a lot.
You might get it more if your battery is a little weak or if your running some extra accessories. I'm running a few wideband controllers off an accessory circuit which throws codes when i've got a lot switched on.

I'm still on the original June 2005 battery and running widebands (off the power plug/lighter socket feed) and the Lappie for logging, never had any codes, even when the battery was drained due to insufficient use.

[LawrenceF]

Does your dash voltage gauge ever show 14 and a bit like it should? Or do they all show about 13?

[MadMaxHSV]

MyM8V8 said:

MadMaxHSV said:

Not one to worry about. I get the 689 code quite a lot.
You might get it more if your battery is a little weak or if your running some extra accessories. I'm running a few wideband controllers off an accessory circuit which throws codes when i've got a lot switched on.

I'm still on the original June 2005 battery and running widebands (off the power plug/lighter socket feed) and the Lappie for logging, never had any codes, even when the battery was drained due to insufficient use.

are we on the same ecu? The entire car complained bitterly when I ran too much off the three pin plug for the smokers pack. Codes and flashing dash lighting.
I get 689's when my lights are on and the fans kick in on start up.
Maybe the plug I'm using is a bad source and runs on a similar circuit to the ecu...