1996 850 no speedo

[ChronicKing]

The VSS on the trans doesn't feed into the module on your car. The abs module sends a speed signal based on what it reads from the wheel speed sensors to the cluster.

Something somewhere is wrong.

Thanks for correcting me, I just find it strange that I had issues with my speedo randomly failing on me, then had my tranny replaced and had no issues with my speedo since then.

Is it possible that during the replacement my mechanic moved some other wires around and that solved my problem?

[Teddy1975]

I pulled the module today, nothing to see, tried resoldering pin 6 and it didn't work.

I guess I'm now on the market looking for a used module without tracs.

[esl_97_850_T5]

Teddy1975,

1. If the ABS (on your '96 850 with an OBDII port) is *not* supplying the VSS to COMBI, it will be quite rare for the COMBI to not report that as an error, unless there were connection problems like Ozark Lee guided you to.

2. Someone from Denmark has submitted data to kwpd3b0_interpreter in 2016-03-05 and 2016-03-06 involving an ELM327 v1.2a.

That user had correctly made the "var use_ATTA = 0;" change to volvo850diag v0.7's volvo850diag_all_ecus_scan.js file, which caused the use of the "ATPP 06 SV 13" and associated commands.

However, the user had **not** made another necessary change for the ELM327 v1.2 and ELM327 v1.2a:

Code: Select all

var use_ATRA_vs_ATSR = 0; 

That 2nd change causes ATSR 13 to be used, instead of ATRA 13 (ie, a command which became available in ELM327 v1.3).

Because ATRA 13 was still being used (and responding with "?" instead of "OK"), the responses to the ECU 51 AE01 (COMBI Read DTCs) and the ECU 01 AE01 (ABS Read DTCs) commands were "NO DATA". The COMBI and ABS responses -- which very likely did get generated by the car (judging from the fact that other COMBI and ABS commands did respond appropriately) -- never made it past the ELM327 to volvo850diag, since the ATSR 13 or ATRA 13 had not been successfully executed. In a situation like this, the "Gleanings" box on the kwpd3b0_interpreter_results.php page will *NOT* make any statement, one way or another, about any COMBI or ABS errors. You can *NOT* infer that there are no COMBI or ABS errors in such a case.

You can only infer that there are no COMBI or ABS DTCs if these two lines appear in the "Gleanings" box:

------ ECU 51 has 0 DTCs.

------ ECU 01 has 0 DTCs.

If this ELM327 v1.2a case describes you, you need to make the extra 1-line edit:

var use_ATRA_vs_ATSR = 0;

then F5 refresh while displaying volvo850diag.html (or run IE afresh if you like),
answer Yes to the allow ActiveX dialog box (or all the "allow script and ActiveX" oriented stuff if you run IE afresh) ,
then do whatever you did before to read the COMBI and ABS DTCs.

This time you should see an "ATSR 13" get sent to the ELM327, and you should see that it responds with "OK". And you should see that the # of COMBI DTC(s) and the # of ABS DTC(s) are reported, regardless how many there are. Of course, the ABS-nnn and CI-nnn designations and some descriptions will also appear for each DTC that exists.

3. The last submission by that Danish user on 2016-03-06 *did* show 5 ABS DTCs (via their freeze frames, even though the DTCs from the EE01 response to AE01 command was not available due to the lack of defining "use_ATRA_vs_ATSR = 0" for the ELM327 v1.2a).

4. By the way, it would really be better that you (or whomever has the ELM327 v1.2a) submit the entire contents of the log from "Full Scan All ECUs", and/or ECU 51 "Full Scan", and/or "ECU 01 "Full Scan" in order to get the fullest picture.

5. After seeing this ELM327 v1.2a case, I made some changes to the soon-to-be-released volvo850diag v0.8beta?? which automatically set use_ATRA_vs_ATSR = 0 when use_ATTA = 0 (even though that change would *not* really be necessary for an ELM327 v1.3 or ELM327 v1.3a).

6. If this ELM327 v1.2a situation doesn't describe you, but you used Vol-FCR or Brick-Diag Free v0.0.6.6 or XantheFIN's "Volvo 850 OBD-II" Android app to read the DTCs, and one of those programs explicitly reported 0 COMBI DTCs and 0 ABS DTCs, then you definitely need to do some wiring debugging. Assume that ABS soldering problems *will* almost always (if not always) manifest as at least 1 ABS DTC.

7. Finally, the OTP Volvo 850 DVD is your friend.

esl_97_850_T5

[Teddy1975]

Hi esl_97,

I used Vol-FCR to pull the codes from the CI and ABS modules and there were no DTCs stored. I will check again tomorrow as my laptop is currently recharging. I've once tried to get an ELM327 clone to work to read out the milage, which I couldn't. When I get some more money to throw at it, I'll try ordering another cable and see if I can get that to work.

Originally I had problems with the ABS light being lit, it turned out to be a broken ABS constrictor ring and bad soldering in the module.
Now the ABS _is_ working, I tried an emergency brake the other day and when the wheels locked up, the system unblocked the wheels. But speedo and odometer as well as the computer does not get a speed signal, or if they do, at least not the true reading. I have to work on the car tomorrow anyway, so I'll pull the module one last time and have a go at it again. If I can't get it to work, I'll start calling junk yards to see if I can track down a used module, even if they want $100+ for it.