Oredigger Posted September 25, 2011 Author Report Share Posted September 25, 2011 Okay, here is the update. I opened up the hood and while looking for a spot to read the voltage at the alternator, I found this here little wire that was loose and dirty. I think it may have gotten loose when I was cleaning the banjo bolt on the PCV system. Can anyone tell me what it does? It looks to be attached to the voltage regulator on the alternator. After I cleaned the contact with MAF cleaner and plugged it in tighter, the voltage at the fuse box was 13.9 Volts. I have high hopes that this fixed the problem, but wont know for sure because the problem was always intermittent. I drove it around a bit tonight and it worked great, but the engine was warm and it has always done reasonably well with a warm engine. Fingers crossed. Link to comment Share on other sites More sharing options...
Oredigger Posted September 25, 2011 Author Report Share Posted September 25, 2011 Forget it. The car still has the problem. I am just going to get a new volvo ETM. This f**king bites. I am so pissed at volvo and Xemodex. GD drive by wire is the worst MF idea. Link to comment Share on other sites More sharing options...
Oredigger Posted September 25, 2011 Author Report Share Posted September 25, 2011 Okay.... new idea. I noticed the coolant reservoir was a bit low, put in some water and it is running great. Since the problem is generally associated with a cold engine, does anyone know of a reason why low coolant might cause an acceleration issue? Link to comment Share on other sites More sharing options...
Ihatespeedbumps Posted September 25, 2011 Report Share Posted September 25, 2011 New idea is a bad one. Adding splash of coolant won't fix anything. You have an intermittent issue, so it seems like coincidence. What is your current voltage at the fuse panel? Are you still getting the same DTC's? Link to comment Share on other sites More sharing options...
Oredigger Posted September 25, 2011 Author Report Share Posted September 25, 2011 Current voltage at the fuse panel is 14.3 volts. ...and there was lots of white smoke after adding the coolant. Link to comment Share on other sites More sharing options...
Oredigger Posted September 25, 2011 Author Report Share Posted September 25, 2011 Oh and, I am not sure about the DTCs. I dont have the volvo scantool, so I would have to take it to the dealer/mechanic to read the DTCs. The DTCs are not ones that can be read with a regular OBDII scanner. There has never been an associated check engine light. Link to comment Share on other sites More sharing options...
Dan A Posted September 25, 2011 Report Share Posted September 25, 2011 I would contact Xemodex. They are very good help at troubleshooting. Have you checked voltage at the ETM harness? Link to comment Share on other sites More sharing options...
Oredigger Posted September 25, 2011 Author Report Share Posted September 25, 2011 Yes, I have dealt with them quite a bit. They have not been able to diagnose the problem. I go back and forth between thinking it is the Xemodex ETM, to thinking it something else like a voltage drop. I have no idea. Xemodex has no idea either. They already sent me a replacement unit once, so as far as they are concerned, it is not the ETM. Two ETMs = ETM ruled out as a point of failure... But I still think it could be a software issue. Link to comment Share on other sites More sharing options...
Dan A Posted September 26, 2011 Report Share Posted September 26, 2011 Again, have you checked voltage at the ETM harness? Unplug the ETM at the harness and turn the key to the on position. Check the voltage across pins 5 and 6 of the harness where the ETM plugs in to (brown and green/white wires). Compare to battery voltage. If you have any voltage drop at the harness it could cause problems. Link to comment Share on other sites More sharing options...
Oredigger Posted September 26, 2011 Author Report Share Posted September 26, 2011 Thanks for the redirect, that is where I was huntin at the begining of the thread. 12.5 Volts at the battery, 11.9 volts at the fuse box. There is a 600mV drop in the line to the fuse box. (keep in mind, the battery is in the trunk) I was thinking I need to replace that battery cable, but I cant find any instructions on how to do so. I would guess its pretty straightforward. I would also like it if there were an easy way to make sure this is the problem before buying a new cable. Maybe I can hook up a jumper cable from the battery to the fuse box. The thing that confuses me though.. The voltage to run the ETM after the car is started, must come from the alternator. And the voltage drop from the alternator to the fuse box has got to be minimal. I am seeing 14.3 Volts at the fuse box with the engine running. Thats what got me to looking at the alternator, I am wondering if the voltage output from it varies too much. But if that were the case, I would think all the electrics would be going haywire, not just the ETM.To answer your question, 11.9 volts at the ETM harness. There is no voltage drop from the fuse box to the harness plug. Link to comment Share on other sites More sharing options...
Oredigger Posted September 26, 2011 Author Report Share Posted September 26, 2011 Okay, things are looking up a bit. I put my jumper cables between the battery positive, and the fuse box, and that seemed to help. I was having the problem pretty severely, attached the cable, and it went away completely. While the problem has always been intermittent, it have never gone from severe to 100% fixed before. I think this is enough evidence to support the purchase of a battery cable. I am going to see if FCP has some. Link to comment Share on other sites More sharing options...
Dan A Posted September 26, 2011 Report Share Posted September 26, 2011 .6V drop is way too excessive. What others have done (me included) is run an additional heavy gauge wire from the battery to the main post on the fuse box. I bought a 6 ga marine grade cable from ebay seller genuinedealz for under ten dollars including the crimped, tinned, and heat shrinked lugs at the ends. The quality of the cable and the work on the ends was excellent. I ran it from the battery and under the main fuse cover on the back side (had to drill/cut a hole so that I could close the cover) and to the main fuse post. I went from a .2V drop to .05V. Someday, I'll cut out the existing old cables and replace those too and route them through the factory spots and make it cleaner. As it is, it's fairly discreet and functional and I figure the 6 gauge cable supplement is satisfactory in carrying the load. I'd also fix the brake sensor issue ;P Link to comment Share on other sites More sharing options...
Oredigger Posted September 26, 2011 Author Report Share Posted September 26, 2011 Yup, I am hoping to get this done soon. According the several auto part websites, battery cables are easy to come by and many places have them in stock. I'll believe it when i see it though. The tricky part it, on an '01 XC70, the battery is in the back of the car. The cable will need to be something like 6'-8' feet long, and I need to figure out how to weave it through the cabin, through the firewall, and to the fuse box post in such a way as to not zap any passengers. I am hoping someone can post some diagrams of the current battery cable wiring (perhaps from VIDA), so I can see how its done. Link to comment Share on other sites More sharing options...
Dan A Posted September 27, 2011 Report Share Posted September 27, 2011 Forgot about that. You should be able to find that here: http://www.matthewsvolvosite.com/volvo-wiring-diagrams Link to comment Share on other sites More sharing options...
Oredigger Posted September 27, 2011 Author Report Share Posted September 27, 2011 Holy Kripes. That was quite a load of information. Thanks for the link. It does have the diagram that I was hoping to find, and of course it is a much bigger mess than anticipated. The whole thing is probably moot though. I drove the car this morning with the jumper cable between the battery positive and the fuse box, and the car still had the problem. I verified that there was 12.3 Volts at the battery, and 12.3 Volts at the fuse box. This was with and without the jumper cable attached. So now my data collection seems to imply that I have not voltage drop along the battery cable. I also verified this with the engine running (14.2 at fuse box, 14.2 at battery) I am back to square one. I have no idea what is causing this. The biggest clue has got to be that it happens when the engine is cold. If the engine is up to temp, the problem goes away. This is what had me doubting the battery cable, as resistance increases with temp. Its got to be some connection, somewhere, that is not being made when the metal is cold, but is being made when the engine is hot due to expansion of the metal. Either that, or perhaps the running conditions specified by the ECM for a cold engine somehow cause a fault in the ETM --and the conditions for a warm engine cause not problems with the ETM. Link to comment Share on other sites More sharing options...
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