Swap didn't go so well...05/06 XC70 engine and transmission

[firstv70volvo]

Finally got the time to try the easy drive test. Failed in pretty much the same amount of time, but this time I get:

TCM-0020, transmission output speed sensor faulty signal

and

TCM-002A, third gear incorrect gear ratio.

So I didn't even get to 4th gear to see if that problem could be recreated

Looks like it's time to swap transmissions. Still haven't found a local shop to do a rebuilt torque converter, since it's the holidays a lot of places are shut down.

Any other advice or suggestions? Also chasing down an issue on (presumably) the intake side, won't stay started unless I keep it revved about 2000 for a minute or so, then settles into a very rough idle. Feeling a bit like throwing in the towel, if I'm being honest.

If there's a problem with the output speed sensor or wiring this might be a better problem to have than an internal transmission issue.

There are two speed sensors, the output sensor is closer the engine on top side of transmission, see photo. The sensors are the same so can be swapped to troubleshoot if the wiring harness has a connector for each sensor, the later model years may have a wiring harness that doesn't have connectors for each sensor so you may not be able to swap the sensors to debug. You can check the wiring and pull the sensor from the transmission to clean debris from it. In the photo the sensors are not installed.

Looking at the sensors it looks like they can be unplugged and swapped. They can also be measured with a meter, you can check the two inputs as a diode measurement infinite resistance in one direction and forward biased in the other direction.

https://www.fcpeuro.com/products/volvo- ... 52#fitment

[VolvoDJ]

Thanks. The harness has connections for both, and I can test / swap sensors with the spare transmission in my garage. I'll try that next, along with checking and cleaning the connectors.

[vtl]

Finally got the time to try the easy drive test. Failed in pretty much the same amount of time, but this time I get:

TCM-0020, transmission output speed sensor faulty signal

and

TCM-002A, third gear incorrect gear ratio.

So I didn't even get to 4th gear to see if that problem could be recreated

Do you have a third gear? Maybe someone managed to remove the B4 band anchor bolt and the third gear is gone now.

Any other advice or suggestions? Also chasing down an issue on (presumably) the intake side, won't stay started unless I keep it revved about 2000 for a minute or so, then settles into a very rough idle. Feeling a bit like throwing in the towel, if I'm being honest.

Sounds like a vacuum leak. Smoke the intake.

I would wait for PDQ, I also have their converted (thanks, firstv70volvo). Omegamachine fixes are also very worthy if you go the rebuild way. Valve body - just buy a new one from GM. It's been a few years and my rebuild still works very very well.

[yanga001]

Do you have a good scan tool that can do live data? I think a data dump of parameters such as fuel trims, fuel pressure, ignition timings, air flow, and misfire counts may help us with the stalling. Polling the speed sensor while driving and watching the solenoid activations may help with the gearing.