2001 V70XC - cruise control and DTC P1238

[jjcrowley]

I have a well maintained 2001 V70XC with 280k miles. We just finished the cars’ sixth drive across the USA.

Any idea why the cruise control would throw a P1238 code, along with message of “Engine System Service (Urgent)” and go into a semi limp mode? (45 mph max and cannot accelerate)

Back Story:
Driving westbound on I40, at about day 3, at 80mph with cruise control on, suddenly the car hesitates and seems to have no power. Above mentioned message and yellow triangle exclamation point illuminated. We could maintain about 45 mph, put the flashers on and noted the next exit was about 15 miles away. A truck driver who was following pulled up behind us and stayed with us most of the way. I thought that was real kind as it was night time and in the middle of no where.

We were able to pull off and use the lights of a convenience store. Took the code reader and I somehow flubbed trying to get the code. Went ahead performed the erase codes function anyway. Car ran perfectly afterwards, and I told my wife not to use the cruise control. No problems for the rest of the journey to Nevada and California. (over a thousand miles)

Heading back home eastbound, I believe somewhere on I40 in Oklahoma, my wife asks if she can try the cruise control. It is set to 75 and all is well… until after about 2 hours, the same message and symptoms appear. We are lucky and pull off into a nearby exit with gas station (daylight this time). I am successful this time in pulling the code P1238. I again use the erase code function. We continue our homeward journey to Virginia with no further issues.

I have seen in the forums that folks are saying the P1238 is the turbo control valve. My code reader is saying, “ P1238 Volvo, Cyl2-fuel inj Circ. Open circ.” Neither makes any sense to me. Any thoughts appreciated. (turbo control valve and hoses replaced 34600 miles ago)

[vova]

It is hard to say what exactly is going on. Ideally it would be great to get the Vida and get specific codes, but not the case here. I would start with simple check of turbo control hoses for leaks. 34500 miles is not too much, but if your hoses are not original chances are they have a crack. However your symptoms to me indicate issue with electric throttle module. 01 used bad magneti marrelli electric throttle bodies and feedback was done via potentiometer which was wearing off..usually they all died around 100k..I had similar issue with this code and it ended up being throttle body. Sent to xemodex for repair and for $350 or so ot was plug and play with new brushless potentiometer and new bearings. Works fine for 50+k now

[jjcrowley]

Thank you for your suggestion. The car has had the ETM replaced at 186k(remember the class action lawsuit) and then a Xemodex overhaul with 35700 miles currently on it.
The turbo control hoses were replaced with silicone type. I check the connections again. It's just weird it seems to have the problem when used the cruise control.

[vova]

Thanks for update. Agree that likely hoses, etm, boost valve are most likely not the problem. Any chance you had time to look over all the turbo hoses to the intercooler and to the intake? Another word of advice-poat your location here and maybe someone local can assist you with vida or post on Craigslist/Facebook needs help with vida Scan. If you would be next to my neck of the woods I would be happy to help at least.