Before taking a box out etc , I would take a sample of the gearbox fluid and check it , if the TQ or any metal component or clutches and steels have failed , it will show in the fluid.
Just put a drop or 2 on white blotting type paper and see what residue remains on the paper.

 

Well, I had two months without issues. I kept putting off posting in case the issue was not resolved. Would you believe that just as I thought about posting a 'yay fixed' note, the intermittent "gearbox fault" signal appeared, then triggered the check engine light with the P0741 torque converter code again.

I switched off the light, replacing the battery right away, but the error anc check engine light came back in two days. That was a week ago. Today, after starting, the car 'juddered', then flashed "gearbox fault, and "restricted performance" before cutting out. I managed to start it again and get home the 7 miles in limp mode. It seemed like it was searching for gears. It's now like a lump in my driveway with "gearbox fault, and "restricted performance" permanently on the screen and it will not even turn over. All other electrics are fine.

I will tell you left my lights on for several hours (with new battery) two days ago) for several hours--prolonged turnover but started. I since drove 70 miles without issues or hard starting so presumably the batter was charged.

My Actron reader is giving the following codes: P0741 (torque converter), P1643 (?), P0560 (?), P1111 (big deal).

Appreciate any insights. Looks like it will need a flat bed, a new torque converter, and maybe more...

 

If it was quite flat as it sounds then 70 miles will not have recharged it anything like enough.

 

Thanks for your response. I really don't think it's the battery with the overwhelming issues I've been having with these fault codes. Also, the car started right up just fine this morning without me doing anything to the battery, but the restricted performance and gearbox fault lights are still there.

I did a 5 minute car-to-car jump with the battery today. "Restricted performance" did leave the screen but immediately upon driving, the car is juddering and threatening to stall at low rpm, PO741 comes right back even if I switch it off. P0741 torque converter came back (I cleared it after jump) and still P0560 system voltage failure, and p1643 (?) persist.

Does anyone else have any other suggestions based on the other codes I provided? Really just a torque converter?

2003 STR.

 

Still sounds like battery is #1 suspect. Read its voltage after standing at least 8 hours and without starting engine. Needs to be above 12.5V.

 

Wish it were that simple. Battery was replaced last week. This issue (now worse) preceded the new battery and was unresolved by battery replacement.

Does anyone else have any thoughts?

 

Well at least look the codes up in the free downloads.

 

I did. Hopefully that addresses your questionably condescending comment without further escalation.

I'm genuinely looking for help from people who've had similar issues.

 

Why did you fail to find them then?

E.g. you put
P0560 (?)
when it's readily found as a battery voltage problem

 

2003 STR. 40K miles.

For those of you following along, I'll do my best to post the results in the hope it might help someone else:

Problem: Intermittent engine cut-out, and limp mode. Intermittent "gearbox fault" goal, and check engine light coming on. No loss of vehicle power. Turns out it likely was two separate issues--one chronic (torque converter) and one sub-acute (issues in wiring harness/loom at the level of the right front wheel arch).

Code #1: P0741. Torque converter. Familiar to many. There was a TSB for my model saying this code may come with check engine light and it's an intrinsic fault with some models. Replacing the torque converter is recommended. This is an expensive job. I would switch the light off, and the longest it went was 2 months, then the dreaded "gearbox fault" light would come on shortly followed by the check engine light. No loss of vehicle persistence. Changing the battery made no difference (even checked a second battery). Voltage in battery is fine. Connections are fine. It would never pass its inspection, and I hate seeing this light. It is now gone with a new torque converter.

Code #2: P0560. System voltage failure. A second break was found in the wiring harness (right wheel arch) in one of the wires. Voltage spikes were intermittently high/low to the ECM on an oscilloscope. This explains the engine "juddering" when the gas was applied. Repairing the wire made the issue and the code go away. Tugging on the rest of the wires in that region did not alter the pattern on the oscilloscope. In hindsight, this is the second broken wire down there (see my previous posts--last one caused misfires to engine coils), and the guard to the wheel arch had a gaping hole for a while. I anticipate it got a lot of water damage in there and the day of the recent fault was preceded by a monsoon of amazing proportions which I drove in. The wiring harness in the wheel arches are apparently weak points in the S-types.

Summary: engine cut-out and intermittent voltage issues were not related to the torque converter/gearbox fault (which was more of a gremlin).

Hope that helps someone else. Love my STR. Appreciate all your help, folks.

 

Thanks a bunch for the feedback!! I really expected the TC replacement to be the end of your problems.

Care to tell us how much and where you found one?
Maybe got yours rebuilt?

We sure would like a picture of that wire harness problem if you can. It has been reported several times and can cause different problems so it’s hard to find. A number people have had DCCV problems related to the wire harness. As our cars age I expect to see more of these types of problems pop up. Just age and miles.

What made you look at the harness? That was good troubleshooting.
.
.
.

 

I recall someone on the UK forum posted a pic of the wheel arch wires but all you really saw was a bundle of thin variously-coloured wires.

 

Based upon my experience with my s type r it ends up being yo-fault for buying one. I had a VDP before this but some girl decided to blow a stop sign and I T-boned her. Totaled the VDP. Didn't have nearly as many problems with it as I've had with this one.