Some mixed news on the Discovery 3 instrument cluster - after the last repair, I thought it was fixed. While it was initially better, it gradually got worse again to the point where it would drop out for a few seconds every 10 hours or so at the wheel.

I took it back to the same instrument repair place as last time, and when I got it back, the thing was completely dead. This is more of a problem than it sounds - the immobiliser trips if the instrument panel is missing or unconfigured, so the vehicle won’t start. It also won’t shift out of park, so it can’t even be towed when in this state. (There is a way to get it into neutral, but you have to get underneath it and physically move the transmission shift cable.)

Luckily, Land Rover had new replacement clusters in stock, so I simply ordered a new one and installed it. But things got a little more interesting after installing it on the vehicle.

The typical replacement procedure is to download the CCF (car configuration file) from the old cluster, then swap in the replacement cluster with the vehicle still powered on. Then program the backed up CCF into the new cluster, do an odometer sync and a VIN learn, and off you go.

This wasn’t going to work for me since the old cluster was dead. Thankfully the GAP IID tool does have a way around this: first, flash the instrument panel cluster to factory settings. Then you should be able to do an odometer sync and VIN learn like in the previous procedure.

This probably only works for new clusters - there is a separate process for used clusters, because the vehicle’s computers are (understandably) reticent about winding the odometer backwards (in the case where the used cluster has more kilometres than the car). As an anti-tampering measure, the odometer reading is backed up in several modules, even the lighting control module!

The other downside is that it loses a lot of settings - time, saved radio stations, and probably other things. That’s all fixable, but still worth knowing.

Anyway, that wraps up a quick update on the instrument cluster, and hopefully provides some useful information for other people that might be struggling.

The good news is, it’s all working now - although the sound it uses for the indicator tone is slightly different so that’ll take some time to get used to.