The service engine soon light came on my '02 P38 and after plugging in my OBD ll unit it showed the code stating it's a 4th gear ratio incorrect fault.

Has anyone run into this? Some other forms suggested it's related to the MAF sensor.

Thanks

 

Not the MAF. Your tranny uses soleniods and 4th is not shifting or not shifting properly. What's the tranny fluid look like? How long has it been since it was replaced, filter changed? Solenoid not working or sticking. A tranny shop that services BMW's would be the best bet IF the solenoid needs addressing.

How many miles on the drivetrain?

 

hmmmm... the tranny computer gets info from the ECU and might display incorrect ratio if the MAF was dirty. At any rate, cleaning it when cold won't hurt you.

 

IHscouts and savannah, thanks for the quick reply.

It may be the tranny. About 6 mths agao I replaced the fluid with Amsol synthetic ATF (but not the filter) at around 92,000 miles and it has around 95,000 miles now.

I've cleared the code and I'll see how long it will go before it pops up again. I will clean the MAF this weekend.

I'm trying to get my annual license/registration here in NC and they won't pass me for an inspection until I travel 80 miles after I reset the codes.

Thanks and Happy New Year!

 

I assume it's the 4.6L. Change the filter, I know how much fun I just asked you to perform. That may help bump up the fluid pressure enough if the code pops again. You still have a mix of fluids. The synthetic may have rinsed small particulate from clutches/plates, valve body and any pooled varnish to the filter. What mode are you in and what did the fluid look like that you replaced? Also have you had any issues with the BeCM and lastly any idea of the service record? Again, I'll assume it was maintained but probably only through the original warranty period. Hope not.

By the way, my favorite LR is the 02 P38. I have a buddy with one, paid 16.5k for it with less than 60k about a year ago. Bought from a LR collector and it was showroom spotless and meticulously maintained. Great vehicle!

....and a Happy New Years to you.

 

Here's some notes from the RAVE:

In the event of an engine speed signal failure, any of the following symptoms may be observed:

In the event of a throttle position signal failure, any of the following symptoms may be observed:

 

Two things, the 4th gear ratio fault is 90% of the time a bad MAF, try cleaning yours with MAF cleaner.
Second you cannot use full syn trans fluid in a trans that did not come filled with it from the factory, they are not compatible and you will have problems.
You also cannot use non full syn trans fluid in a trans that came with full syn from the factory.
You must stick with the type that it came with.
Is that whats causing your problem? I dont know for sure.
All I know is that others have tried switching to full syn trans fluid and they all had problems with the trans after words.
Change the filter, do a machine trans flush and switch back to the regular trans fluid.

 

Thanks spike.

I kinda fiqured it may have been due to the full synthetic.

I will clean the MAF first and see if I can drive the 80 miles or so to get inspected and hopefully the light won't pop on. I will take the truck back to my independent Rover wrench and have it done right this time.

 

IH?

I bought mine back in '07 for $9,500. It was the summer of hurricanes and gas prices were hitting $4.00 gallon and the guy I bought it from just wanted out. I added the later model 19" wheels along with lamp guards.

I work out of my home and only put around 4,000 miles a year on the truck so 14 mpg doesn't bother me.

 

It very well could be the MAF, but usually, there will be a P0171 and/or P0174 stored as well. Or at least see fuel trims unusually high. I just fixed a Disco II last week with that same code and it needed a MAF.

Not only does the MAF calculate incoming air, so the ECU can determine correct fuel mixture, but it also calculates engine load, which is a very important parameter for the transmission. Cleaning only works on 50% of MAF problems, but if it does help, that is money saved.