fastsuv

My daughter called yesterday and said she couldn't back out of a parking spot because it wouldn't go into reverse. She said it just revs up, like neutral. I asked her if it was acting funny at all before that, and she said it was "harder to get the car going" and to accelerate. I went there and sure enough no reverse. I had it towed home since I had free towing. No check engine light, but the following codes were there: P0700, P0741 and P0756. P0741 is the TCC and P0756 is shift solenoid "B". This is on a 2007 LS 2.2 with 300K miles. I have the service manual for my 2006 HHR, but it doesn't show a "P0700" code, but I think that's a "transmission control" problem.

Is there a solenoid failure that would cause reverse to not work?

The "No Reverse" troubleshooting chart in my 2006 service manual doesn't mention any electrical problems in the possible causes, only internal mechanical issues. It does mention low fluid level, but there are no leaks and I tried adding a half quart that I had but no difference. I guess I can put it on the lift tomorrow and actually check the level at the plug.

Any ideas?

Steve

donbrew

Since all of those codes are transmission codes I would start at the TCM connector and fuse. And hope it is that simple.
The CEL only lights up for Emissions related codes.

Greybeard999

I wonder how long this was going on... "it was "harder to get the car going" and to accelerate." before it just didn't move anymore.

firemangeorge

Yeah. Sounds like a mechanical issue. So what does it do in Drive ?
My guess is it's slipping. Also because of your quote from her, " "harder to get the car going" and to accelerate." I would think the clutches are burned up.
If you check the fluid and find it low, topping it off may not help. Seems like the damage is already done.
With that many miles it's time for a rebuild or used transmission.

Oldblue

Check the TCM harness for loose connections.

https://www.obd-codes.com/p0700

https://www.obd-codes.com/p0741

https://www.obd-codes.com/p0756

all three point to possible wire harness issues.

fastsuv

Here's another odd clue:

When I was testing it last night, I compared the "revving" in Neutral vs in reverse. When I revved it up in neutral, the car would creep forward as though it wasn't completely in neutral.

I looked at the linkage and it looked good, and when placed in reverse the reverse backup lights illuminated.

Steve

Cat Man HHR

Well you know the reverse light switch works.
The trans is toast. Have it fixed.
I bet you if you drop the pan, fluid will be burnt and you'll find clutch material.
That's my gut feeling.

fastsuv

I'll drop the pan tomorrow and look at the fluid and check for debris.

First I have a couple of oil changes to do before I tie up the lift.

If the trans is shot, local junkyard wants $300.

The trans shop that I use and trust says they will install a reman unit for $1200-$1400.

So I can save about $1000 doing it myself. Its not hard to replace the trans, especially with a lift. Just a lot of disassembly. Hopefully the cradle nuts would not break loose, but I already know how to handle that. That would be with a used trans that has no guarantee on how long it would last. The trans shop would be a reman unit that theoretically should be somewhat like new with a warranty. Some decisions to make soon...

Steve

fastsuv

I still find it odd that it creeps slowly in neutral when the engine is revved.

Mechanical trans failures usually mean lots of extra slipping, not extra engagement in a gear (neutral) where there should be none. Maybe a solenoid not completely releasing? I'll have to think about this one.

I'm going to check the resistance of the solenoid coils at the TCM connector to see if it's in spec (as per the service manual).

More troubleshooting to come.

firemangeorge

No need to do all those other checks until you drop the pan. Bet you'll find the answer there.