Another electrical issue please help

[05stroker]

First thing I do when there is an issue is change the plugs. Not always the issue but most of the time. Now I need to figure out how to test spark plugs off the car since i have 12 used sets here at $100 per set. Lol

 

[swflastang05]

First thing I do when there is an issue is change the plugs. Not always the issue but most of the time. Now I need to figure out how to test spark plugs off the car since i have 12 used sets here at $100 per set. Lol

Yea for sure, I have about 5 sets now, catching up to you! I tried testing them with a meter, I found they all have anywhere from 5k - 9k ohm resistance so IDK.

I'll be ordering another set tonight though!

 

[redfirepearlgt]

Glad you got that ironed out. Was interesting working through the PCM relay circuit even though everything turned out okay. As long as the car is running well I would not worry about the DTC's AND make a note of them for future so you can ignore them for the most part. I would still like to know why that print did not match your wire code and pin out on C1035A,B. Must have been a revision that never made it to the prints, or the prints are an older version.

Knock em dead at Bradenton! And remember to keep that hood closed! LOL!

 

[swflastang05]

Glad you got that ironed out. Was interesting working through the PCM relay circuit even though everything turned out okay. As long as the car is running well I would not worry about the DTC's AND make a note of them for future so you can ignore them for the most part. I would still like to know why that print did not match your wire code and pin out on C1035A,B. Must have been a revision that never made it to the prints, or the prints are an older version.

Knock em dead at Bradenton! And remember to keep that hood closed! LOL!

Yes I reflashed the ECU and the codes are still there! The car drives good now though. Maybe they'll go away after I put some miles on it without the bad spark plugs. I saw some pics online during my research that showed other BEC's with the same wiring as mine, that did not match the diagrams, so something is up with that. Luckily the Pin diagrams on the ECU/PCM harness (c175a, b and c) did match my car so I was able to check those wires directly right before they went into the PCM.

Yes Bradenton is back on the schedule again, now I just need to decide which class I'm going to run in for sure, either TS or MM (only considering MM so I can open my hood between rounds lol).

 

[swflastang05]

I'm resurrecting this thread since my previous motor blew up, now I have a completely new motor but still have the same codes P0689, P0830 and P0833. I'm pretty sure there was a time when I did not have these codes, and I don't want to blow up my new motor so I want to deal with this before I lean on it too hard. Just for fun I checked the ac voltage again and found its around .120 at idle, in reviewing this thread I see it was .07x back in February so it's getting worse. I also checked three other mustangs with 4.6 engine and found them all at .02x. In light of this I think my alternator is crapping out, I've read that ac voltage in a dc system can cause all kinds of weird shit so I'm going to swap it out and see if that helps. I know there are other codes a bad alternator can cause, maybe it's causing these codes too.

 

[bcb06gt]

You have a scan gauge or ability to log the voltage? When my alternator was going out, the voltage was all over the place from 10-13.x volts. I set my Aeroforce on the system voltage to see what it was doing. In the morning and evening, the voltage would dip enough (10.x range) that the dash lights would dim for just a second.

 

[swflastang05]

You have a scan gauge or ability to log the voltage? When my alternator was going out, the voltage was all over the place from 10-13.x volts. I set my Aeroforce on the system voltage to see what it was doing. In the morning and evening, the voltage would dip enough (10.x range) that the dash lights would dim for just a second.

Yes I have an aeroforce gauge, although I swapped out the alternator with one from my wife's 06 GT then cleared the DTC's. I'll hopefully have time to test drive it tomorrow and see if it made any difference. If nothing else it's down to .020 ac volts now.

 

[Wild White Pony]

Kyle I'm thinking this is a wiring harness issue or something with the computer. Since we talked last about this P0689 code, I haven't been able to get rid of it either after the 4R70W swap.
What was your original PCM code for that auto, mine was VDX1, we flashed a manual code from an exact year 2006 mustang GT to the computer and pulled the P0689 code right away. A couple of other issues too, the emissions would not set as the evap, cats and o2s would never complete cycle, the rear passenger reverse light would stay on all the time. I just pulled the bulb for the time being.
Figured we try having a Ford tech reflash the pcm with the IDS software so I could have the proper miles on my computer with the vin number matching hoping that would set the emissions but that didn't work either. Same P0689 code and no change in the emission status.

The last thing which concerns me is in my case when you start the car it runs open loop, then closes like it should, then opens back up and never closes again. Probably why it won't set emissions status.
Will tune it now in open loop as it's a bit rich, otherwise it runs fine, have logged 500 miles on it so far without any driving issues.

Lastly, after about 250 miles the P0689 and the P1000 did clear, but a P0351
Ignition coil A Cop-A Primary/secondary CK T appeared. I changed the plug and cop, checked with a noid light and everything seems to be working.
Cleared the DTC and after startup checked the DTC and wouldn't ya know it the P0689 code appeared again.

Will be following your thread here for sure.

 

[swflastang05]

Kyle I'm thinking this is a wiring harness issue or something with the computer. Since we talked last about this P0689 code, I haven't been able to get rid of it either after the 4R70W swap.
What was your original PCM code for that auto, mine was VDX1, we flashed a manual code from an exact year 2006 mustang GT to the computer and pulled the P0689 code right away. A couple of other issues too, the emissions would not set as the evap, cats and o2s would never complete cycle, the rear passenger reverse light would stay on all the time. I just pulled the bulb for the time being.
Figured we try having a Ford tech reflash the pcm with the IDS software so I could have the proper miles on my computer with the vin number matching hoping that would set the emissions but that didn't work either. Same P0689 code and no change in the emission status.

The last thing which concerns me is in my case when you start the car it runs open loop, then closes like it should, then opens back up and never closes again. Probably why it won't set emissions status.
Will tune it now in open loop as it's a bit rich, otherwise it runs fine, have logged 500 miles on it so far without any driving issues.

Lastly, after about 250 miles the P0689 and the P1000 did clear, but a P0351
Ignition coil A Cop-A Primary/secondary CK T appeared. I changed the plug and cop, checked with a noid light and everything seems to be working.
Cleared the DTC and after startup checked the DTC and wouldn't ya know it the P0689 code appeared again.

Will be following your thread here for sure.

Damn, sorry to see you're still having that issue too. I did see in the FB instructions that section you referenced that talks about getting the code for "low voltage to aux relay", I'm not sure if that's the same issue or not though since mine says low voltage to the ecm/pcm (not the aux relay). I drove mine today with the different alternator and of course there's no difference, all the same codes are still there. As a matter of fact another little fun fact is I cleared the codes, then turned the key off then immediately checked the codes again and the damn P0689 code was back without even starting the motor! The other codes came back too after I drove it. The strategy code on mine is BKT3. I'm talking with Manuel about trying to swap the ecm/pcm from my wife's 06 to mine to see what happens with the codes, this would confirm if the ecm/pcm is bad or not, I think. He said since I have a separate handheld tuner (x3) for each one he should be able to send me a tune for the strategy code in her ecm/pcm but for my car and with the pats shut off it should work. I'll definitely post up the results if we end up doing that.

 

[swflastang05]

We swapped out the pcm today and it had the same damn P0689 code soon as I turned the key on, didn't even have to crank the engine. So it's looking like an issue with my wiring harness or possibly the bec. Guess I'll start by double checking all the fuses in the car, then go from there, maybe swap out the bec with my wifes car too just to make sure. One benefit of having two s197's to troubleshoot with..

 

[Dino Dino Bambino]

Since you've done a tranny swap, make sure that one of the O2 sensor wiring harnesses didn't get accidentally pinched by the bellhousing resulting in a short.

 

[swflastang05]

Since you've done a tranny swap, make sure that one of the O2 sensor wiring harnesses didn't get accidentally pinched by the bellhousing resulting in a short.

Nothing pinched in the bellhousing, thanks for the suggestion though. This is the same issue now with two different motors, it may have contributed to my previous motor blowing up actually..

So today I swapped out the BEC, and it made no difference. Tomorrow I'm going to swap out the ignition switch, since I've read that can sometimes be related to this DTC. I've already triple checked all the grounds, redid a couple of them, but it made no difference. If the ignition switch doesn't fix it I'm not sure where to go next.. makes me want to rip out the OEM unit and go with an aftermarket system like
Fueltech, Haltech or something along those lines, if only Lito tuned those..

 

[Tbone]

Found this troubleshooting guide, may help find where in the harness the short or open is.

http://juchems.com/ServiceManuals/viewfile6aa8.pdf

 

[swflastang05]

Found this troubleshooting guide, may help find where in the harness the short or open is.

http://juchems.com/ServiceManuals/viewfile6aa8.pdf

Thank you very much for that, I ran some of those tests today with no luck, meaning everything tests okay. That's what's making this such a difficult problem, everything tests fine it's just the DTC in the PCM. Today I pulled the DTC's with only the power harness (center plug) plugged into the PCM, everything else was unplugged and it still had the P0689 code. It's got to be a wiring issue somewhere but where. I have a buddy that's an ASE Master Tech, I'm trying to get him to stop by this weekend to at least point me in the right direction. He's seen and fixed these codes before, mostly in f150's. He said most of the time it's a ground issue.

 

[Wild White Pony]

Hello Kyle, I'm going to post some pics with the obd code reference, I was unable to link it as they took it off the view list at the site. The way this leads is that since both of us had auto pcm's and harness and both have the same problem it's got to be a problem with the harness and pin outs, I think once we flashed that manual program in it rearranges the output pins. I'm pretty sure it's looking for a reference voltage to ground that it's not seeing since the harness is different. I'll make another post with what I'm taking a guess at could be one of the problems (clutch switch).

 

[Wild White Pony]

I know that a pause happens when you try and start the vehicle and one of my reverse lights stays on, so I'm looking close at this harness. When you and I setup the start inhibit circuit we took the wires shown for the auto to close the circuit with a switch on the shifter Wires 33 and 32, the actual color I think for the wires was RED/Blue and Pink/White but the pins were correct at 10 and 12. I think in the manual setup they have a clutch pedal circuit that will inhibit the start of the vehicle if not depressed, clutch position switch and deactivator switch. Both go to a ground so it may be something the pcm is looking for when we flashed the manual strategy, I need to look at that reverse light circuit too but I've been work busy so I haven't got this checked yet but I think this could be a start.

 

[swflastang05]

I've seen that write up in my research, I was getting excited to maybe have something to look into but then I realized it's for DTC P0698 but my car has P0689.. You might have something though with converting to manual wiring, here's something else I found during my research, I don't even remember where, maybe here at s197. This lines up with what you're suggesting. I remembered that my reverse lights stayed on 100% of the time also when I first did my swap, I just cut the wire in the trunk to shut them down at the time.

The manual cars definitely have a clutch pedal position switch and deactivation switch, as well as an additional PCM relay, "aux relay box #1" located next to the throttle pedal. My wife's car has all that stuff in it, I was looking at it the other day considering unplugging it from her car and into mine to see if it made any difference. I found the harness in my car up high under the dash on the DS, it just has a loop in the plug on the end where it connects those three devices in manual cars, must just bypass that circuit for auto strategy. The pins could definitely be different though with manual strategy, I've found several examples in my car in the harnesses that don't match up with the wiring diagrams maybe that's why. Also explains why my wifes PCM showed those codes right away too, it's manual looking for that signal from the clutch pedal, maybe. I'll look more into this too in the next few days as time allows.

 

[Wild White Pony]

That code is similar as far as the result in circuit voltage being low, unfortunately they don't give out the P0689 link without signing up I guess. The effect of the problem is where I think need to look as It's got to be some type of ground reference voltage. So happy to hear that the harness part for the clutch pedal is tucked up inside the dash. Since we flashed a manual strategy you could copy the FB way of inhibiting the start circuit. The way we have it now is using the auto start circuit, who knows what the pin outs are for at this point on 10 and 12 though it seems to work on inhibiting the start. If you use your wifes aux circuit relay and clutch pedal switch and disconnecting the 33 and 32 wires from the current circuit that may be 1 variable down.

 

[Wild White Pony]

Well now looking at the Manual/Auto schematics, it would seem we may need to wire together 33 and 32 leaving them hot, then use the clutch pedal switch to inhibit start, closing this circuit would give a ground voltage reference for the start circuit and maybe causing a low voltage sensor signal to the PCM.

 

[swflastang05]

Well I removed the entire clutch pedal harness from my wife's car this afternoon including the pedal position switch, deactivator switch, and aux relay #1 and plugged it into the same harness in my car. The result is this had no affect on the 689 code, however, it did eliminate both clutch pedal codes! The P0830 and P0833 were gone, then soon as I unplugged that harness and reinstalled the loop plug they came right back, so there's definitely something to that.

Here's the entire harness assembly

Aux relay #1

part number

Another interesting fact, just for kicks I tried cranking my wifes car with the harness unplugged and of course it did not start. I pulled the DTC's and there were none, then I installed the loop plug from my car and tried again, it started that time but still no 689 code.