2006 XC90 V8 AWD Constant push when stopped Topic is solved

[klauzon1]

******FIX******** Have a 2006 xc90 v8 with identical condition with code p0506 indicating can't reach target idle. The code after clearing would only return if left in gear with brake held tight. My engine in park was at approx. 700 rpm when in gear with brake tight 500 rpm with the engine trying to drive through the brake. Contacted our local dealer 2 hrs away, asked them to check if the software or transmission are out of wack for this vehicle as it was a recent auction car. 1 week and $250 in diag time the idea was to replace throttle body (est. 900). Due to being used volvo specialized dealer I opted to swap from a known good car. DID NOT CHANGE ANYTHING. I changed out the valve body in the trans due to fact volvos experience heavy wear in the valves of the trans not usually the trans it self. NO CHANGE. Decided to get a used transmission. **********FIXED********** As suspected the problem had nothing to do with the idle condition the problem was with the torque converter of the transmission causing a lower engagement idle (stall speed) than the vehicle was designed for making the engine module think it needed to do all it could to raise the idle. This would be the same as putting in gear, holding the brake and stepping on the gas. Important note:These forums seem to be great at sharing the strange problem modern cars have, yet we have to remember to take as much time sharing the fix as these new vehicles are very difficult to figure out and even the dealers have no idea either. Modern cars are great but we need to have a lot of understanding to survive.

[oragex]

Appreciate the feedback. This topic may go into the repairs section.

[jimmy57]

That sounds like the TCC (torque converter clutch) is being applied to some degree. The TCC solenoid could cause this as could a problem with the TC flow control valve. TCC is applied by reversing fluid flow through converter that is for cooling.

[mrbrian200]

Modern cars are great but we need to have a lot of understanding to survive.

It's approaching levels of skill and understanding that 30 years ago would have rivaled the knowledge of an airline engineer/mechanic (Several technical AS culminating with a Masters degree). A two year ASE 'crash course' simply doesn't cut it anymore unless you mostly aspire to balance tires and perform brake jobs.

Is there a theory as to why this issue seems to affect XC90s and not other models fitted with the TF80-SC? Which is pretty much any Volvo 2005+ equipped with a 6-speed AT.

[goldmandan]

sorry to revive an old thread but i have a 2007 S80 with the 4.4 V8 and I have the same problem! I recently replaced the valve body with a rebuilt one because the transmission used to bang the gears in pretty bad. Once new valve body was in it shifted nice and smoothly but this high rev when at a light started coming up... As if what was said before "like putting your foot on the gas and the brake at the same time". I first thought it mimicked a vacuum leak, but then I thought i'd have a check engine light on. I checked my booster, there is no pedal position sensor, only the vacuum check valve which was installed and tight and there was another electrical sensor of sorts, i unplugged it and got the same exact thing with the high idle and wanting to run away on me while sitting at a light in gear. Also the "Service brake system" message came on the dash immediately when I disconnected that sensor so I take it the sensor was doing it's thing. I do have a bad torque converter seal leak now that the valve body has been changed out. I am assuming the torque converter is the culprit and since i'm thinking to pull the transmission to redo the seal and engine rear main seal I may as well put a new torque converter in it.

Any thoughts if that should fix the problem once and for all?

Dan

[BFCVOLVO]

Dan,
I am new to this forum. But i too have the same problem. i put a used tf80-sc in from a 2005 mine is a 2007. i had to change the tcm the gear selector which is the tcm and a new valve body. and when in gear feels likt your are power braking. I took The 2007 xc 90 awd v8 to volvo they checked the software and everthing and they said the same thing to me . "Put a New Torque Converter" I will have it done by 10-17-18. I will let you know how i make out. i have not found any other information on this issue
Adam BFCVOLVO

[Popdaddy12]

Had anyone solved this problem.I am having the same on 05 v8.some say converter other valve body.trying to determine if worth keeping??? thanks

[matthew1]

It's 6 posts above yours on this very page. Just scroll up:

klauzon1 » July 3rd, 2018