scott schmerge
Full Access Member
Just had it and was able to get it corrected. It’s your reservoir valve block. Easy rebuild. I need to put some new o rings in mine, but a good cleaning has kept it free of faulting.Got a new suspension fault today. Sometimes it goes away after a restart, other times it doesn't.
IID Tool says it's C1A18-64. "Pressure increases too rapid when filling reservoir - Algorithm based failure - signal plausibility failure."
A search on this and the LR3 subforum turned up no hits. A general google search turns up some hits on a range rover forum that indicate it could be a valve issue near the air tank. The algorithm part of the code seems odd, though.
It's still under CPO, so I'll take it to the dealer early next week.
Essentially the valve that controls air flow to the reservoir stays closed, therefore “pressure increases too rapidly”. Suspension continues to function correctly, but reservoir is also unable to fill suspension due to stuck valve. Raising to off road height takes longer than normal as well (I’m guessing).
I spent about an hour total on the repair and it cost me $0 to fix. (Least expensive fix I’ve ever had on my 8 rovers I’ve owned)
Apparently when the valve sticks the algorithm determines a blockage to the reservoir (the stuck valve) and intermittently generates the “pressure increases too rapidly” message. Another interesting symptom is when the valve sticks, the reservoir can’t release air pressure so the vehicle raises very slowly (using only compressor air instead of combination). Once the valve was cleaned, all symptoms back to normal.
For the repair:
1. Use gap iid tool (or other ECM control) to depressurize the system.
2. Remove compressor cover
3. Valve block sits right in front of compressor, remove two electrical connections and four air lines.
4. Open valve body by removing three torx screws
5. Clean four o rings in the valve body. There are three on the little metal cylinder. My fourth and smallest was stuck up in the valve body. It was very clear to me the one that was sticking as the assembly is spring activated and it was stuck together (no spring action) upon disassembly.
6. Reassemble and refit.
7. Use gap tool to repressurize system
8. Check for leaks (I heard slight leak and had to refit one of the lines)
9. Replace cover and you’re done