'98 V70 GLT Transmission problems...

Post by **bmdubya1198** » 25 Sep 2015, 16:31

I've seen some other threads about this, but I think I can't figure out what is wrong with my transmission. Here are the problems...
-Hard jerk when shifted into reverse, RPM drop
-Drop in RPM when shifted into drive
-No up arrow light
-When the W button is pressed, there is no light.
-When accelerated in drive, it is in a higher gear (3rd). From what I've read, the transmission is in limp mode.
I have VOL-FCR and a VAG-COM KKL cable. I successfully read and cleared SRS codes and codes for my climate control, but I can't get codes from the transmission. When I try to connect to the transmission, the program tells me that it cannot communicate with the car, and to make sure the ignition is in position II, which it is. For some reason, that system won't work, and neither do the other top "Engine/system ECUs," meaning the service light reset and Motronic 4.4 fuel injection.
Since I cannot get codes, I've come to the conclusion that the two biggest things it can be are the PNP switch or the TCU.
So two things...
1- How can I get VOL-FCR to read transmission codes with my VAG-COM KKL cable? I have the port set to COM1 and everything connects OK except for the main ECUs. I use the VAG-COM cable because the VOL-FCR serial cable that came with the software didn't work with any of my computers, and I tried two different USB serial adapters, including one made by a reputable brand.
2- From the symptoms I listed, does anyone know what might be the culprit? I figure I can get a TCU for fairly cheap at the junk yard, and if I can find the same version as mine (from a 1998 model, of course) it might fix my problem.

Post by **bmdubya1198** » 25 Sep 2015, 18:08

Just getting an idea... could it be that the TCU can't be reached from the scanner because it's bad?

Post by **esl_97_850_T5** » 26 Sep 2015, 01:18

bmdubya1198,

1. My guess is that you have a discontinuity between the OBDII port's pin 7 and both the Motronic 4.4 ECU and the AW 50-42 ECU. That would be one thing that could explain why Vol-FCR can not connect to either one of them, but it can connect to at least SRS and ECC.

After all, in one of your posts -- https://www.matthewsvolvosite.com/forums ... 79#p376838 -- in your "build" thread, you mentioned that you "found some broken wires coming from the ECU", yet I never saw anything in that thread where you said you corrected that "broken wires coming from the ECU" problem. I'm presuming you were referring to the Motronic 4.4. I'm wondering if those "broken wires" might have also broken or corrupted communication with the AW 50-42.

If there is a discontinuity somewhere between the OBDII port's pin 7 and both the M44 and AW 50-42, then I would expect that the standard OBDII emission diagnostics should also fail -- regardless whether the scanning is done with some handheld OBDII scanner, or an ELM327-compatible device, or whatever?

A wiring diagram showing the path from OBDII pin 7 to the connected ECUs would be useful.
And a reexamination of any "fixes" to the "broken wires" problem might be prudent.

2. What do you mean by "everything connects OK except for the main ECUs"?

Are you saying that the following Vol-FCR buttons do not work?

- Reset Service Light?
- Motronic 4.4?
- AW 50-42 Petrol?

And are you saying that the following buttons do work?

- SRS? Yes [you've already demonstrated that this works in your "build" thread"].
- ECC? Yes [you've already demonstrated that this works in your "build" thread"].
- ABS?
- Instruments?
- Immobilizer 2/3?
- RTI?
- VGLA?
- Power Seat Left?
- Power Seat Right?
- Add Heater 912-D? Let's ignore that one.

Since you said "everything connects OK except for the main ECUs", and since you did *not* say the "Instruments" connection failed, and since you said the "Reset Service Light" failed, and since "Instruments" and "Reset Service Light" use the same ECU (ie, COMBI, aka ECU 51), please include a picture of the successful "Instruments" connection (similar to what you did in the "build" thread for the SRS and ECC).

I'm using Vol-FCR v1.7.3 FTDI Demo buttons as my reference, so if there's any differences in your Vol-FCR v1.3 buttons, please let us know.

And if there's any of the ECUs which your car doesn't have, please say so.

3. I'd be inclined to making sure the OBDII pin 7 / K-line bus connectivity and connectivity on any wires between the M44 and AW 50-42 is verified before throwing replacement TCMs at the situation in the cross-your-fingers hope that will solve the problem.

4. Ensure all fuses work.

5. Some references for a '97 850 that might be applicable to your '98 V70:

- https://www.matthewsvolvosite.com/downlo ... iagram.pdf

and:

- http://www.volvo-forums.com/index.php?s ... st&p=38324
- http://www.volvo-forums.com/index.php?s ... st&p=38325
- "auto trans diagnosis.pdf" in Volvo_850.zip (downloadable from MVS)
- http://www.volvotips.com/index.php/850- ... g-diagram/
- http://www.volvopedia.de/index.php?titl ... ne_CAN_Bus
- https://www.matthewsvolvosite.com/volvo- ... 96-to-1998

Especially notice on the two volvo-forums.com pages the suffixes "1)" thru "6)" and "*)" thru "**)".

View the volvopedia.de Fehlercode-Tabelle page with Google Chrome while Chrome is auto-translating.

And you might find some other useful links at:

- http://jonesrh.info/volvo850/volvo_850_diag_links.html (especially if you decide to use Brick-Diag Free v0.0.6.6 with your VAG/COM KKL cable), or

- http://jonesrh.info/volvo850/index.html (especially if you explore using an ELM327-compatible device with appropriate software as an alternative to the VAG/COM KKL / Vol-FCR / Brick-Diag Free approach).

esl_97_850_T5

Post by **bmdubya1198** » 26 Sep 2015, 10:03

I will double check all of the wires either later today or tomorrow.
Yes, the buttons on top do not work (Motronic 4.4, service light reset, and AW 50-42)
Now that you mention it, the Instruments function did not work, either. I can't remember for sure all of the functions that didn't work, but I remember Instruments was one of them. SRS, ABS, ECC, Immobilizer, and I am pretty sure Power Seat Left all worked fine. Not sure about any of the others.
I will definitely double check all fuses, because I've already tracked back at least two problems to a bad fuse (horn and wipers).
AFAIK, all of the buttons on v1.3 are the same as v1.7.3.
I think this is probably because of those wires in the engine. Like I said, that's the first place I'm going. I'll report back after I go over all this information. Thanks!

Post by **bmdubya1198** » 28 Sep 2015, 08:37

I swapped the TCM with one I got at the pull a part, and it did nothing for me, as I expected. I went through all of the wires coming from the ECU box, and I can't find any other breaks. I might have to look further along those wires, but I can't find anything. The transmission is still in limp mode, and the scanner still cannot connect to the transmission. I don't think it was able to connect to the instruments, either.
What can I do now? I'm not replacing the entire wiring harness, but I don't know which wires I should look at. I'm not horrible with electronics, but I'm definitely not the best. Which of the many wires in that loom coming from the box should I check for breaks?

Post by **bmdubya1198** » 28 Sep 2015, 16:03

I checked all fuses, they are all good. It has to be a wire.

obayha · Post by **obayha** » 28 Sep 2015, 19:11

How long is the wire harness before it has connections?
Come and pull all the wires you want, before this thing goes to the salvage.
A T5 and a GLT should be the same.
Shane

Post by **bmdubya1198** » 28 Sep 2015, 20:11

obayha wrote:How long is the wire harness before it has connections?
Come and pull all the wires you want, before this thing goes to the salvage.
A T5 and a GLT should be the same.
Shane

They should be. I am probably going to have to take things apart again (ugh) and get a better look... again. All I did yesterday was take apart the box and the wire covers at the box. I think I may be onto something now, because my dad mentioned that the ground didn't seem to be connected properly.
The wires seem to go on a while. No clue where they end. I hate this, because we're so close, but there's this one small thing keeping me from getting it on the road.
I'll definitely let you know if I end up needing to replace a wire or two.

Post by **esl_97_850_T5** » 28 Sep 2015, 20:51

bmdubya1198,

1. Definitely explore your dad's "ground didn't seem to be connected properly" hint.

2. Maybe this wiring diagram will be useful:

1997_850_wiring_diagram.pdf

It might help in figuring which wires to check. Focus on the page labeled "Group 37" / "On-board diagnostic system (OBD system)". To understand the numbers on that wiring diagram, search for "Component List missing elements" on the http://jonesrh.info/volvo850/volvo_850_diag_links.html page and use the cheat sheet to focus on the ECUs which you know do work:

- 4/9 (SRS),
- ?? (ECC) [this '97 850 diagram does not show how a '98 V70 ECC is connected to pin 7, so ask around about this],
- 4/16 (ABS),
- 4/22 (Immobilizer -- Note: This wiring diagram said Immobilizer was strictly for EU/OS, but did not include US/CDN, so I question if you can use this 4/22 info reliably to debug anything on your car. Are you sure Vol-FCR connected to it?),
- 4/29 (Power Seat Left),
- ??others probably not applicable??.

and focusing on the ECUs which you know do not work:

4/28 (AW 50-42),
4/46 (Motronic 4.4),
5/1 (COMBI) [See note below.],
- ??others probably not applicable??.

That might help to isolate the problem.

Inferences from '97 850 wiring diagram, assuming it applies to '98 V70:

- 4/9 (SRS) being good implies the leg from OBDII pin 7 to 23/421 is OK.
- If 4/16 (ABS) could be connected to by Vol-FCR and Hardware/Software Version/Revision #s read and DTCs read, then the (USA/CDN) leg from 23/421 to 24/2C is good.
- Since both AW 50-42 and Motronic 4.4 can not communicate, maybe the leg from 24/2C to 4/28B:22 (ie, AW 50-42 pin B22) is bad, or maybe the cage that you seat the TCM and ECM into is bad, or maybe the ECM is bad, or maybe its something else on those last 2 legs leading to Motronic 4.4).

Draw your own conclusions.

Note: I wouldn't put a lot of significance in the fact that COMBI doesn't connect, since many of the '98 S70/V70/XC70 have problems establishing a COMBI connection. Reason unknown. So I would diagnose first as if the COMBI did work. Then I would diagnose as if the COMBI did not work.

Of course, if you can get your hands on a '98 V70 wiring diagram, that would obviously be better.

The following are some other minor debugging ideas. I doubt that you'll need to do them. But you might try them out of frustration...

Since there is one case here at MVS that documented well how a butchered ABS module disabled the entire OBDII communication system, you might consider removing the ABS module, then seeing if you can magically begin to talk to either the transmission or the M44 either using Vol-FCR or your OBDII scanner (or other tools which have been mentioned, eg, Brick-Diag Free v0.0.6.6 with VAG/COM KKL, or volvo850diag with ELM327-compatible tool that fully implements ELM327 v1.4 compatibility).

You might also be able to isolate the ABS from the OBDII circuitry by removing all 3 ABS fuses, instead of physically removing the ABS module. Or, come to think of it, you could probably just disconnect the ABS connector, without actually physically removing the ABS module.

Furthermore, you might be able to play "divide and conquer" of the OBDII circuitry by removing the fuses for each of the respective ECUs one at a time, between each attempt to connect to the TCU, to see if one of the other ECUs is a culprit.

3. If you get too exasperated, please don't junk the car. At least consider selling it to one of us.

4. My guess is:

a) something relating to wiring, grounding, etc where the ECM and TCM are plugged in, or
b) the leg from 24/2C to 4/28B:22 (ie, AW 50-42 pin B22) is open or shorted.

May your eyes be led to the precise problem location.

esl_97_850_T5

Post by **bmdubya1198** » 29 Sep 2015, 08:45

esl_97_850_T5 wrote:bmdubya1198,

1. Definitely explore your dad's "ground didn't seem to be connected properly" hint.

2. Maybe this wiring diagram will be useful:

1997_850_wiring_diagram.pdf

It might help in figuring which wires to check. Focus on the page labeled "Group 37" / "On-board diagnostic system (OBD system)". To understand the numbers on that wiring diagram, search for "Component List missing elements" on the http://jonesrh.info/volvo850/volvo_850_diag_links.html page and use the cheat sheet to focus on the ECUs which you know do work:

- 4/9 (SRS),
- ?? (ECC) [this '97 850 diagram does not show how a '98 V70 ECC is connected to pin 7, so ask around about this],
- 4/16 (ABS),
- 4/22 (Immobilizer -- Note: This wiring diagram said Immobilizer was strictly for EU/OS, but did not include US/CDN, so I question if you can use this 4/22 info reliably to debug anything on your car. Are you sure Vol-FCR connected to it?),
- 4/29 (Power Seat Left),
- ??others probably not applicable??.

and focusing on the ECUs which you know do not work:

4/28 (AW 50-42),
4/46 (Motronic 4.4),
5/1 (COMBI) [See note below.],
- ??others probably not applicable??.

That might help to isolate the problem.

Inferences from '97 850 wiring diagram, assuming it applies to '98 V70:

- 4/9 (SRS) being good implies the leg from OBDII pin 7 to 23/421 is OK.
- If 4/16 (ABS) could be connected to by Vol-FCR and Hardware/Software Version/Revision #s read and DTCs read, then the (USA/CDN) leg from 23/421 to 24/2C is good.
- Since both AW 50-42 and Motronic 4.4 can not communicate, maybe the leg from 24/2C to 4/28B:22 (ie, AW 50-42 pin B22) is bad, or maybe the cage that you seat the TCM and ECM into is bad, or maybe the ECM is bad, or maybe its something else on those last 2 legs leading to Motronic 4.4).

Draw your own conclusions.

Note: I wouldn't put a lot of significance in the fact that COMBI doesn't connect, since many of the '98 S70/V70/XC70 have problems establishing a COMBI connection. Reason unknown. So I would diagnose first as if the COMBI did work. Then I would diagnose as if the COMBI did not work.

Of course, if you can get your hands on a '98 V70 wiring diagram, that would obviously be better.

The following are some other minor debugging ideas. I doubt that you'll need to do them. But you might try them out of frustration...

Since there is one case here at MVS that documented well how a butchered ABS module disabled the entire OBDII communication system, you might consider removing the ABS module, then seeing if you can magically begin to talk to either the transmission or the M44 either using Vol-FCR or your OBDII scanner (or other tools which have been mentioned, eg, Brick-Diag Free v0.0.6.6 with VAG/COM KKL, or volvo850diag with ELM327-compatible tool that fully implements ELM327 v1.4 compatibility).

You might also be able to isolate the ABS from the OBDII circuitry by removing all 3 ABS fuses, instead of physically removing the ABS module. Or, come to think of it, you could probably just disconnect the ABS connector, without actually physically removing the ABS module.

Furthermore, you might be able to play "divide and conquer" of the OBDII circuitry by removing the fuses for each of the respective ECUs one at a time, between each attempt to connect to the TCU, to see if one of the other ECUs is a culprit.

3. If you get too exasperated, please don't junk the car. At least consider selling it to one of us.

4. My guess is:

a) something relating to wiring, grounding, etc where the ECM and TCM are plugged in, or
b) the leg from 24/2C to 4/28B:22 (ie, AW 50-42 pin B22) is open or shorted.

May your eyes be led to the precise problem location.

esl_97_850_T5

I am going to check the wires as far as I can go. I will definitely check out the ground(s) to make sure everything is connected. I'm going to look over that diagram and see what I can find.
Don't worry, I already like this car too much to scrap it. Hell, I feel bad for the cars at the pull a part, and this one '98 S70 has already helped me tremendously with parts! It takes a lot for me to decide a car is ready to be junked.