Hi All,

I need your help!

I have a LR3 - My Hitachi Pump failed so I bought a German replacement (Hitachi Style), I fitted it and hey presto it was working. I took my truck into Europe last week and it all went wrong! The suspension would state “suspension Fault” Seconds after turning the engine on. Sometimes I will get the Max speed 30MPH error too.

I have JLR SDD tool so I’ve done the following:

-updated the firmware for the pump
-reset the suspension tolerance

I did not reset the Ride level control unit has it required measurements which I don’t have the tool for.

The errors I’m getting are:

C1A13-64

U0421-68

I have replaced the compressor for another one as i thought this was faulty but this has made no difference. The Compressor does not make any noise - with exception of when you have switched the engine off you can hear an electrical buzz or high pitched whistle coming from the compressor.

ive checked the lines are plugged into the compressor correctly I’m not sure what else to do?

Any help would be amazing!

Thanks

D

 

If the fault is happening in seconds after startup, its likely a hard fault.

Please post what the codes mean, not just the codes. While we can look them up it saves time if you can post the meaning of them please.

U0421 - invalid ride height data
C1A13 - pressure does not decrease when venting

If its a hard fault, it could be a defective hight sensor that is showing way out of spec, a valve block, a fuse, a relay or wiring. Typically if the compressor itself is at fault, it will try to run for up to 30 seconds before a fault is thrown. If that happens its usually that the pump is drawing too much current. Being new pumps, as you suspect, they should not be the issue.

Did you try a hard reset (battery disconnect for a few minutes)

Lastly, what firmware update did you do and when? There are at least two I believe. One is a basic one that changes compressor run-time to reduce heat and thus wear on the pump. I think this update was early on and most vehicles may have gotten it as part of maintenance at some point by now. They other is one that is only applied when charing compressor brands, like from Hitachi to AMK. If that firmware was applied, then maybe there is an issue as there certainly is when people swap brands and do not update. But it sounds like you did the firmware after it was working for a while and only when you had issues, right?

So first code - not sure, could be anything. But I would check all your height sensors for any physical damage and possibly move onto actually testing them with a meter.
Second code - that usually indicates a problem with the exhaust solenoid on the compressor. Does the truck drop at all? Of course with a new compressor that would have been taken care of. There is also a "galley" pressure sensor on the middle valve block. Just forward the compressor. If that valve block is disconnected or that sensor is reading false data, you could get the error maybe. A clogged compressor dryer could also be at fault but again with new compressors, new dryers.

As for the sound it makes, there should be none after engine shutdown expect some venting. Noting like a whistle. A sound like that makes be suspect the vent line is damaged in some way or there is a system leak. Verify lines are fully seated into the dryer AND the intake/exhaust lines are seated properly.

 

Hello

Thank you so much for the reply, Yes of cause I will do for the future.

I have checked all the fuses and relays and these are all working. Yes I tried a Hard reset twice with no effect. Also tried clearing all the codes but same effect.

I will need to look the firmware up, but I did two updates as directed by the SDD software. But yes it all worked for approx 1000 miles until the fault. The unit is the hitachi (a replica).

I will next test the height sensors as suggested - the truck doesn’t drop sits perfectly so I’m guessing this leans towards no air leak.

is there a simple method for testing them Gallery sensor?

the noise I’m hearing is an electrical whine after the engine has been shut down. It comes from the compressor - if you disconnect the wiring harness (6 cable one) it stops immediately.

Kindest

D

 

There really should be no noise post shutdown except venting. I suspect a faulty compressor.

 

I am curious if the original poster solved this issue as I have a similar problem with the pressure not releasing and an electrical whistling coming from the solenoid on the compressor.

 

I do wish folks would update threads when they can. I know sometimes its not always possible but so may meet a horrible death with no conclusion to help others. 3and4, electronics dont normally whistle. How do you know pressure is not release? Have you ran codes?

 

I have a Gap iid and been trying to resolve issues after replacing the compressor. I am leaning towards a faulty exhaust valve. I have removed the solenoid and tracked the sqeal to the solenoid only partially opening when on the vehicle. When wired up to 12v off the vehicle it clunks as expected.

I connected the old solenoid and got the same result that led me to think it was a wiring issue. This may be a red herring as the ECM could be limiting the negative trigger as it is not able to gather other needed inputs.

I checked the exhaust valve on the new one and the chamber was blackened after a short period of operation. Given that the suspension raised and lowered normally for a few journeys, it is worth changing for $40CAD.

 

There are two exhaust valves in a way. You have the pilot valve which is the large one and a small relief valve. The small one you can get in a kit which is just a spring and a rubber part. When that one starts to fail usually the vehicle is slow to raise. But it also acts as an over pressure release. You could trace wiring back as far as you can and use a couple jumpers with the exhaust solenoid. I think almost all the EAS wiring is exterior with mucho fit meeting at the rear side of the from wheel wheel liner area. Also its a sorta known issue that wires in this area can rub apart. So it may very well be worth looking things over.

 

Had same issue. 2006 Range Rover Sport.

In my vehicle the filters inside the desiccant dryer attached to the compressor pump were clogged, which resulted in slow venting when the vehicle was lowering.

I was also having issues with intermittent faults triggered by C1A13-64 error code (Gallery pressure does not decrease when venting) as well as Suspension in extended mode errors.

When the vehicle sends signal to lower, it opens the exhaust valve and the front right / left valves, which in my case caused an increase in the pressure on the gallery pressure sensor (because the pressure vents through the desiccant dryer, which was clogged, and the increased pressure from the front springs caused a spike in the pressure on the gallery pressure sensor when the front right/left valves open and the exhaust valve can't vent the pressure quickly enough).

Replaced the desiccant filters and desiccant, reassembled and so far it looks to have resolved both issues. Huge difference in the amount of time it takes the vehicle to lower since the air can now flow freely.

Hope this helps someone.