BCU woes in '99 D2... Need some advice from a LR tech with T4 experience

[tscottg]

I purchased a '99 D2 with a bad BCU.

To remedy this as a testing procedure I had an extra BCU/ECU matched combo and replaced the pair and everything worked great and the truck runs good but the mileage flashed on the odometer.

The truck has 113k miles and the donor truck for the BCU/ECU had 190k miles. I work at the dealership and I used the T4 to run a odometer update which changed the mileage in the cluster to 190k :banghead:

So after a few conversations I realized that I basically screwed up in a way that is irreversable.

I bought a second BCU and Insturment Pack (ECU was not available) from another used truck with 116k miles and was told that the T4 can reprogram the used BCU to work with the ECU. When I attempt to do this through the "Computer Replacement" in the Vehicle Configurator screen on T4 it tells me that the BCU is locked and obtain one that has not been previously programmed.





My question is....Is there a step that I am missing to de program the used BCU?


Thanks in advance!

Scott

 

[jafir]

The BCU isn't what gets programmed. The ECM is set to recognize the code sent from the BCU. My nanocom does say it can reset the "new" flag on the BCU under the odometer section, but I still couldn't get it to sync any direction but "higher" miles.

 

[ptschram]

It will only burn the higher milage into the BCU/instrument panel.

Working at a dealership, I'd expect you to have known this. I'm glad this wasn't a customer's truck you "Tampered" with the mileage.

At this point, your only course fo action is to send the instrument panel/BCU to a rebuilder and have them burn the correct mileage, or obtain an ECU/BCU/instrument panel from a donor vehicle.

How did you know you had a "Bad" BCU? I've found them to be VERY robust, especially when compared to the P38. Everytime I've had a BCU sent to me for work, it has ALWAYS been something with the truck, most often, the left front door lock actuator having a fault.

 

[jafir]

It will only burn the higher milage into the BCU/instrument panel.

With his newly installed matching BCU and cluster, he should be able to get the ECM to sync with the BCU security code.

 

[crown14]

Yeah I think he just needs to do a security learn?

 

[discostew]

It will only burn the higher milage into the BCU/instrument panel.

Working at a dealership, I'd expect you to have known this. I'm glad this wasn't a customer's truck you "Tampered" with the mileage.



We dont work on Discos much in the dealer P.T. , You guys have more old Disco knowledge than most guys in the dealerships . We moved on to some really crazy stuff now . Most guys who worked on them left when Land Rover stopped paying well.
The LR2 stores milage in the drivers door latch and the same problem will accure , learned that the hard way by installing a latch from a box that had been opened .

 

[ptschram]

It will only burn the higher milage into the BCU/instrument panel.

Working at a dealership, I'd expect you to have known this. I'm glad this wasn't a customer's truck you "Tampered" with the mileage.



We dont work on Discos much in the dealer P.T. , You guys have more old Disco knowledge than most guys in the dealerships . We moved on to some really crazy stuff now . Most guys who worked on them left when Land Rover stopped paying well.
The LR2 stores milage in the drivers door latch and the same problem will accure , learned that the hard way by installing a latch from a box that had been opened .

I'm learning about other brands as well with the new gig.

GM ties things like window switches to the BCU. Radios are VIN-specific and part of the On-Star system!

I learned VERY quickly in a short time how much dealer techs really knew. I had to reverse engineer everything as I didn't have access to GTR.

 

[jafir]

My question is....Is there a step that I am missing to de program the used BCU?


Thanks in advance!

Scott

Tell it you are replacing the ECM instead maybe. Or see if there is an option just to have the ECM learn the BCU code. On my nanocom I just go to the ECM menu and tell it to learn the code.

 

[pdxrovermech]

i've ran into this problem with something as simple as an alternator failure causing a surge and then the BCU thinks it has 9 million miles on it. the odometer would always read correct but would constantly flash. our computer couldnt sync it and even the dealer couldnt remedy it without suggesting to replace both components and none of my customers have ever wanted to spend the money on doing that.

 

[jafir]

i've ran into this problem with something as simple as an alternator failure causing a surge and then the BCU thinks it has 9 million miles on it. the odometer would always read correct but would constantly flash. our computer couldnt sync it and even the dealer couldnt remedy it without suggesting to replace both components and none of my customers have ever wanted to spend the money on doing that.

You can reprogram the BCU to not check for the miles, even if you cannot sync it. That's what I did on my 99 when I repaced the ECM and BCU, because I didn't have a computer that could sync.

 

[discostew]

You can reprogram the BCU to not check for the miles, even if you cannot sync it. That's what I did on my 99 when I repaced the ECM and BCU, because I didn't have a computer that could sync.

How do you do that ? I know on the LP Range Rover you come to a screen that asks if you want to lock the BECM to the vehicle and you answer no if you dont want to lock the vin to the new BECM . How do you make the BCM on a Disco 2 not update the odometer ?

 

[jafir]

It's just an option in the BCU setup, to blink on odometer errors. I know I can turn it off with hawkeye or nanocom. I assume most others will too. It doesn't sync anything, it just stops the blinking.