# Code P0688 ECM Power Relay Load Circuit: (J271): Open Circuit



## 02' 18T (Jan 15, 2005)

I have been searching around on here and can't find a whole lot about this particular code. I have replaced the ignition switch and my issue is still persisting. 
Details:
02' GTI 18T 
APR 91
EPC light came on a week or so ago 
Code: 17072/P0688/001672 - ECM Power Relay Load Circuit: (J271): Open Circuit 
This has been an ongoing issue back in December it started when i was slowing to a stop and all the electronics shut off radio, dash lights, headlights all lights. But the motor stayed running, after about a second of me freaking out everything came back on and I was on my way. 
Well now it's to the point that when im slowing to a stop the car has died fully electronics and the engine, but when you try to start it it won't start. The lights on the dash won't come on and it won't crank, so after fiddling w/ the keys turning in to start nothing take the keys out try again, i do this several times untill it wants to work w/ me.. Now meanwhile all this is going on the clock and the odometer dim and when in the start postion they disapear completly, when i pull the key out of the ignition the clock and the odo. flash dim, to normal you can also hear a clicking noise coming from the dash near the fuse box. 
I have had a shop look at it they said everything looked fine and suggested that it was most likely the ignition switch, so i got a new one from the dealer changed the part today and just as i finish the replacement WHAM, starts the same issue so it's not the ignition switch. Brake lights work just fine.... and w/ the clicking it sounds like the relay up there is making the noise but that sounds/seems like it's fine just almost a voltage issue proly too little. The shop is kinda out of suggestions there suggestion was to check the APR SW, or the battery terminals.
Sorry for the long post, i just didn't see any that really pertained to my issue so trying to give as much info as possiable. 

Here is the Wiki-ross http://wiki.ross-tech.com/inde...01672 
Any input will be much appreaciated thanks ahead of time.


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## Uwe (Jan 16, 2000)

*Re: Code P0688 ECM Power Relay Load Circuit: (J271): Open Circuit (02' 18T)*

The link you posted doesn't seem to work. This one should:
http://wiki.ross-tech.com/inde...01672
Nothing there points at the ignition switch. Personally, I'd try a new J271 relay. If that doesn't fix it, check ECU and wiring.
-Uwe-


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## eb (Mar 24, 2006)

this problem is usually caused by corroded battery and earth cables or a loose connection in engine bay around the vacinity of the battery. there is also a wiring junction under dash next to steering collumn where alot of main supply cables bolt on.check for loose connection.


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## 02' 18T (Jan 15, 2005)

*Re: (eb)*

Great suggestions thanks i will swap out the relay and clean the terminals when i was swapping out the ignition i was looking and made sure all the connections uder that half were ok. I will keep you all posted, i generally steam clean my engine bay, w/ degreaser so the terminals are pretty clean all ready, what would you all suggest i should use to clean the terminals that may increase the contunity of the connection. Coke-Cola.. lol, WD-40, Brake Claener, soap and water. The battery is about 3 yrs. old how often do you all change your battery?
I pray at night that it isn't a faulty ECU...










_Modified by 02' 18T at 8:23 PM 5-19-2007_


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## 95GrannyGolf (Mar 30, 2007)

*Re: (02' 18T)*


_Quote, originally posted by *02’ 18T* »_ i generally steam clean my engine bay, w/ degreaser so the terminals are pretty clean all ready, what would you all suggest i should use to clean the terminals that may increase the contunity of the connection. 
_Modified by 02' 18T at 8:23 PM 5-19-2007_

It's not the connector exterior that causes issues, it's a buildup of corrosion between the connector and its mating surfaces on the interior. Corrosion doesn't conduct electricity well.
Best for push-on connectors is repeated mating and removing with electrical contact cleaner available at an electronics repair place, with possibly some tightening up of the mechanical connection by gently bending the bits that grab terminals. 
For bolt-down connections, nothing beats wire brush, anywhere from 80 to 150 grit wetordry (emory), sometimes even a small file. When you can clean both (top & bottom) surfaces of a ring connector, plus all flat surfaces around the bolt/stud, plus the stud threads, that's ideal. (Access may limit what you can do, of course).
On my GolfIII::
On both ground and power sides, I found significant corrosion on the TCU and ECU connectors, corrosion between the ECU, its carrier, and the plenum where it mounts, bad corrosion on the engine grounds, bad corrosion on the ground strap from coil to head... though you won't have the latter.


_Modified by 95GrannyGolf at 6:47 AM 5-20-2007_


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