Swapping Clusters / Mileage Mileage Will Not Accumulate - keywords accumulate BCM counter inop inoperative IP IPC increase instrument locked MEC miles odo odometer swap tire

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

In the cluster there is a component called a MEC (Manufacturing Enable Counter) that counts down from 256 to 0 and reduces 1 count per ignition cycle. When the counter gets to 0 the cluster is "Locked" and therefore whatever VIN is in the cluster at that time remains and it is locked. When you put a locked cluster into another vehicle the trip mileage will accumulate and roll over at 999.9, but the regular odometer will not increase. The mileage is stored in the BCM so when the correct cluster is put back in the mileage should read correctly.

Note: Production (Fairfax) made a recent change to set this MEC to 0 when it passes DVT. Therefore when a car gets to the dealership and you swap a cluster (for testing purposes) it will not work correctly.

You can swap in a new cluster from another vehicle, but you would need to drive it for greater than 1 mile to verify that the regular odometer will increase. If it increases then cluster will work in vehicle, but if the mileage doesn't increase (remember that trip odometer will increase) then cluster has been locked (MEC = 0) and can't be swapped.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.