Hey guys,

My Forester has been throwing a P0741 (torque converter) error lately when I'm on the highway and I'm looking for a shop that can accurately diagnose the problem. It could be the transmission harness, connector, a bad ground, bad TCM/ECM, bad torque converter solenoid, etc. Who knows.

I've taken it to a couple shops around home and they don't seem to know how to diagnose it - even though the service manuals lists out step by step a number of things to check, with many of them being electrical and requiring some knowledge of the components, connectors, and a multimeter. The two shops I went to, after seemingly fumbling around, told me I need a new transmission - which might be true, but they couldn't clearly tell me how they came to this determination (and they didn't remove the oil pan - how did you check the lock-up solenoid?).

Thus far, I have not been able to find anyone who can do this - besides myself but I can't get under my car as I park in a shared garage! I was thinking of going to Walnut Creek Subaru, as they seem to have good ratings, but I'd prefer to not go to a dealer.

Any guidance would be appreciated. I live in South San Francisco - don't mind traveling a bit if needed.

 

Mert at Rbms in Hayward has all of those cool gadgets to do that stuff

 

+1 for RBMS. There are a bunch of solenoids (9 or 10) on there and they do go bad with age and I'd say that's the most likely culprit. A good shop like RBMS will be able to find out if that's it and which one.

 

If you are looking to not cross the bridge go to adam aquino @aa motorworks

 

Thanks guys - much appreciated. Will give them a call - anybody know what I should expect for $$$ for troubleshooting like this? For a knowledgeable mechanic, shouldn't take more than an hour.

 

I called RBMS....they said they could take it for a "test drive" but didn't really have the equipment to test for problems like this. ???

 

4EAT? I've never taken an auto to him, but I would have expected them to be able to handle it. I took my former GF 4EAT to Garage 1 in SJ and they fixed it. Adam @ AA maybe then?

 

Yeah, 4EAT. Starting to hate this POS transmission. Car only has 90k on it!

 

My GF had 250K before it started. Sorry to hear it. It is actually a good auto, but the solenoids go. That does seem early though. Give Adam a call and see what he says. I know a transmission guy, but again, he's in Santa Clara.

 

250K?? Man, that would be great! Yeah, I'm wondering if it's a solenoid...but I'm also wondering if its something electrical - a connection/connector. It got his issue after the seller pressure washed the engine bay...water went everywhere.

I'm really hoping it's not a solenoid as I don't believe they sell the individual solenoids - you have to buy the whole valve body which can cost as much as a used transmission! If I have to do that, I might either buy a used transmission or think about a 6MT swap...

 

What is the problem besides the CEL? Any mechanical issues, whines or slippage?

 

No other problems. The car drives and shifts fine - I only get this code when I'm on the highway going up hills that have a slight grade - that's when the AT Temp light starts blinking and I get a P0741 error.

But my RPMs seem to be fine??? At 65 mph, I'm right around 3,000 RPMs (a little below), which seem to be where it's supposed to be. When I hit the gas hard at that speed, the RPMs do jump a little bit, so that might indicate the torque converter is not locked? I've checked the trans fluid - it doesn't smell like it's burned - still looks new (I just flushed it last month).

 

Have you checked the front differential Fluid? I would be shocked if the torque converter is the problem.

 

Yeah, it looks/smells fine. I just had it changed out 2000 miles ago by Mann Engineering down in Santa Clara who did my 90k service.

Yeah, me too. I really have doubts it's the transmission.

 

With mine, it would whine or clunk when you put it in reverse and throw a light. Mann couldn't find it but Garage One in Almaden was able to figure out which solenoid and fix it, but it took them 2 days. Probably not the fluid IMO. PM'ed about another shop in Santa Clara.