Using the GAP Tool on an LR4: What It Shows and What It Doesn’t

The GAP diagnostic tool is powerful, but it does not diagnose the vehicle for you. In this video I walk through how I use the GAP tool on my LR4, what its fault descriptions actually represent, and where interpretation still matters. Fault codes describe what the ECU observed, not which component failed. I also touch on live values and why they’re often more useful than stored faults, especially when you’re trying to understand system behavior rather than chase error messages. A suspension “pressure rises too slowly” fault is a good example: the tool reports a condition, not a conclusion. Misreading that difference is how parts-cannon diagnostics start. C1A18-64 (68) or P0915, the code is just part of the equation, not the whole thing! Related LR4 videos referenced: LR4 solar trickle charger and voltage behavior:    • Solar trickle charger on the Land Rover LR4   LR4 P0915 transmission fault (internal failure vs wiring):    • This Tiny Hidden Sensor Almost Totaled My ...   LR4 suspension fault diagnostics (earlier suspension context):    • Land Rover LR4 suspension fault fix