46 replies to this topic

[Oredigger]

Hey, just found this forum, hopefully it will prove more helpful than others I have visited...

I have a 2001 XC70 with ETM issues.

Wait, its probably not what you think. I replaced the ETM with a Xemodex unit, and am having more and different problems. The first ETM simply had a bad idle and a check engine light, there was no associated limp home mode. I decided to replace it with a Xemodex unit, as I was just out of warentee and I wanted a more permanent, and less expensive solution. However, the Xemodex unit went into limp home mode and the idle was horrible. Xemodex sent me another unit, this one has a smooth idle, but does still go into limp home mode every so often, usually when the engine is cold. The associated codes are:

ECM-91A7
ECM-91F0

Which seem to indicate a bad battery or bad battery cable. Can someone tell me where to get, and how to install a positive battery cable on an '01 xc70? I did a search on this forum but nothing came up.

[ARD - Lucky]

Both those codes come up as throttle unit internal fault.

There is a possibility that this code can be caused by low voltage to the unit but a voltmeter test would not take long to confirm that, at the ETM connector of course.

Im wondering if they got the wrong software in there when they loaded it for your car? That's also one of the possible causes listed in VIDA / VADIS and I've seen it more than once

[Oredigger]

Hey thanks for the quick reply, I am accustomed to waiting days for replies on volvo forums.

I was just checking to voltage on the ETM connector yesterday, it was 11.53 volts if I remember correctly. This was with the engine off, (obviously, the ETM was unplugged), but with the ignition on. There was 11.9 Volts between the battery positive cable at the fuse box, and the body of the car. I did not check the voltage of the battery.

[Ihatespeedbumps]

What is your voltage with the engine running?

[Oredigger]

I think it was 12.5 Volts between the positive battery cable at the fuse box, and the body of the car, with the engine running.

[nyc1dxo]

When I had ECM-91A7 as an error, the dealer replaced it under the 10year/200,00 mile plan. I wish you luck in finding your solution.

Just to add, my code ECM-91A7, never resulted in a Limp Home mode.

[Dan A]

This may help.

http://volvospeed.co...kind-of-problem

I went through something similar earlier this year. Ultimately I ended up getting a replacemremt ETM which solved my problem but there's a lot of info in there that may help you out. Voltage drop at the etm can cause issues. I know I had voltage issues also, which I remedied and probably helped as well. Anyway take a read.

[Oredigger]

Thanks Dan A. That was a helpful thread. I am concerned that yours ended up being a bad etm. Considering I already received one etm replacement from xemodex, I am thinking they may not be such a good deal.

I double checked this evening, and I noticed, 11.9 V at positive battery cable, 11.5 V at etm fuse. Does that make sense? Why would I loose 0.4 volts at the fuse box? There may be some corrosion or loose connection in there somplace.

Nice ID image BTW. I have always been more partial to Jezza, but Capt Slow is a close second.

[Oredigger]

I noticed this morning that I could start the car without my foot on the brake. This says to me, that the car may think the brake is being applied all the time. Could this lead to a situation where-in, the ECM cuts power to the throttle because it thinks the brake is applied?

I also have code ECM-9400, which I had ignored up until now, because I thought it had only to do with the brake pedal sensor. I do need another brake booster as mine has the vacuum leak at the seal, a slight hissing can be heard near the pedal at idle. I had not thought these problems were related, but maybe?

[Oredigger]

And while I am discussing random codes, I also have PSM-0038, power seat module, incorrect software. I have no idea why that is, I am pretty sure it is the original seat. It is frustrating because the seat will not work properly, but that has always been the case since I bought the car, very doubtful this is effecting the ETM.

[Ihatespeedbumps]

Oredigger, on 22 September 2011 - 07:58 PM, said:

I think it was 12.5 Volts between the positive battery cable at the fuse box, and the body of the car, with the engine running.

Voltage WAY too low for proper opertation. I think you should start looking at the alternator...

[Dan A]

Oredigger, on 23 September 2011 - 03:27 PM, said:

I noticed this morning that I could start the car without my foot on the brake. This says to me, that the car may think the brake is being applied all the time. Could this lead to a situation where-in, the ECM cuts power to the throttle because it thinks the brake is applied?

I also have code ECM-9400, which I had ignored up until now, because I thought it had only to do with the brake pedal sensor. I do need another brake booster as mine has the vacuum leak at the seal, a slight hissing can be heard near the pedal at idle. I had not thought these problems were related, but maybe?

I would replace the sensor first. See here (especially last post for resolution):

http://www.volvoforu...hp/t-27291.html

Also agree that your voltage is too low. I would suspect there is some voltage drop in the cables. Often this stuff is the result of more than one cause, so I would take care of both.

[Ihatespeedbumps]

Brake pedal positon sensor will not cause or eliminate ETM codes.

OP: Please check voltage at the alternator post, if it's not above 13.5V you need to replace the alternator! Low voltage issues in these cars can cause a variety of issues, and replacing the brake pedal position sensor will not resolve your issues. These sensors do go bad and will prohibit cruise operation, but they DO NOT cause ETM interference or any other poor running condition.

[Dan A]

Well if nothing else it will resolve the brake pedal sensor code.

[Oredigger]

Hey thanks for the help, I am hopeful that I can get this solved given this information. The wife has the car today, so I wont be able to do further investigation (voltage at the alternator) until this evening. I think it is likely a voltage drop from the alternator to the fuse box, or possibly a corroded/broken solder on the fuse box. Anyhow, I will post with updates.

[Oredigger]

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.

[Oredigger]

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.

[Oredigger]

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?

[Ihatespeedbumps]

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?

[Oredigger]

Current voltage at the fuse panel is 14.3 volts.

...and there was lots of white smoke after adding the coolant.