V70 XC, operates normal in reverse, accelerates slowly at first in 1 Topic is solved

[Rocket999]

What was the code which your "volvo guy" cleared?
Don't drive it like this... you will fry plates in the transmission.

1631, he said its vacuum leak in the area just under intake plenum wrapping around driver side of engine
that is an area possibly affected by collision impact pushing things around
thankfully no other codes, even my low brow Blue driver code reader shows that one
thx for that advice
not driving it its not insured
occasional short runs locally..... above 5 to 7 mph trans seems normal

need to do the finish work paint the hood, polish out the sun damaged black plastic parts of the bumper
denatured alcohol with schotch brite pad made that go quick, then "back to black" it will look great
isopropyl alcohol + lacquer thinner 50/50 also worked well

when I first got this car a code did clear itself with a bit of freeway driving
don't recall, may have been flashing vertical arrow remedied by new PNP from volvo

[Rocket999]

Now going up a steep grade it slows down if I move the lever D to 3 to 2 to 1 a feel a bump going into 2 not 3 or 1.

Getting it rolling from zero up to 7 mph where it is normal seeming is not too much stress. I'll be driving it

[misha]

https://www.fixya.com/cars/t26999137-20 ... _dtc_p1631

It's TCM request for ECU to turn on the CEL.

Your car have CAN network and these 2 modules are not communicating to each other.

Along with no start situation you had before because of broken wire somewhere in the loom....there might be other broken wire(s) which interrupted CAN network in the car.

Aside from more complicated CAN network...no communication between ecu & tcm in a non CAN network car(pre '99) would also lead in non functional transmission since the tcm doesn't have info about engine load from the ecu.

[Rocket999]

https://www.fixya.com/cars/t26999137-20 ... _dtc_p1631

It's TCM request for ECU to turn on the CEL.

Your car have CAN network and these 2 modules are not communicating to each other.

Along with no start situation you had before because of broken wire somewhere in the loom....there might be other broken wire(s) which interrupted CAN network in the car.

Aside from more complicated CAN network...no communication between ecu & tcm in a non CAN network car(pre '99) would also lead in non functional transmission since the tcm doesn't have info about engine load from the ecu.

Thx Misha this helps me begin to understand better.

Below are new observations

1. That no start problem: it resolved l when I "found" that "lost" branch of the loom that extends from driver side across top side of fan shroud and connects with a 5 pin connector on passenger side. Apparently that "broken" wire was actually a "lost" wire, ie a branch of the loom i shoved back toward the firewall. This was the first serious work under the hood on a Volvo, began with dismantling shattered to small pieces radiator support and pack and wiring. Sorting it out was a big deal. That branch of the loom also contains the large gauge wire supplying current to the cooling fan. Plugging those two in enabled normal crank and instant starting.

2. The vertical dashboard lite never illuminates even when turning key to II. Prior to the accident it would be on when shift lever was moved from D into 3, 2, or 1. When I first got the Volvo I saw it flashing, I put in new PNP from Volvo as flailing attempt to correct it, only recall PNP didn't appear to be the problem. I was swamped ( 2 dead brothers, one by hanging suicide, the other brain cancer within 2 months in 2017, my brain was oatmeal) my focus was on other imperatives and never did nail down that flashing arrow but it stopped flashing.

3. Now, the first roading since accident repair : the trans lever in position 2 or 1 does shift it into lower gear I'm sure it is 2. So with shift lever in position 2 or 1 it begins to move from stationary in gear 2 and does not seem to stress the trans as much. In 5 sec. more or less its up to 7 to 10 mph +/- seeming to operate normally, move lever into 3 or D for normal traffic and freeway speeds. In position D it is starting to roll from stationary in a higher gear, 3 or 4, that would seem to be a situation to not drive it (as you recommended) due to stress you suggested before. Even at higher speed moving lever shifts it to lower gear noted by tachometer showing higher RPM.

[Rocket999]

could the pnp have taken a hit in the accident and be damaged?

[misha]

Do you have back-up lights(reverse lights)when you put a shifter in "R"?

[Rocket999]

Do you have back-up lights(reverse lights)when you put a shifter in "R"?

Yes, thx for the intelligent idea to check of PNP adjustment perhaps messed up in accident impact. I assumed so far that reverse lighting circuit would be the "one stop" easiest single check to verify adjustment.

[misha]

Then...PNP switch is working fine and it's aligned.

Dtc you have is no communication between ecu & tcm via can network.

That needs to be sorted out.

[Rocket999]

Then...PNP switch is working fine and it's aligned.

Dtc you have is no communication between ecu & tcm via can network.

That needs to be sorted out.

Thx misha, working on it blindly now , but workin ....

would remove ECM and TCM and cleaning contacts, inspect the area for wire defects make sense?

I did find a big leak (vacuum??, that would be boost pressure) in the area indicated by the code reader guy, the tube clamp connected strait out the end of the intake plenum was not tightened. That tube would have pressure (turbo boost). Did not clear that code. I need to take all possibilities seriously until resolution

I do take your input seriously so thank you

[misha]

You can try to re-seat both of them but i would focus at the area of impact during collision.

CAN network is compromised somewhere in the wiring loom at the time of accident.
You mentioned that problem wasn't present before the accident...so you have a starting point.