Thread: Need assitance with fault code: 04-05 electrical fault in directional control valve 1

Originally Posted by thumperer

Hi all,

I could really use some help figuring out what the error code is pointing to. I'm not having any luck finding it online
The exact fault code on the Nanocom reads: "fault 04-05 electrical fault in directional control valve 1 circuit (fault 29)"

Does anyone know what it means?

Thanks!
Matt

Something in the ACE system valve body. I'm pretty sure Nanocom lets you run a test through the ACE system. You may need to clear the fault first. Make sure there's no-one close by, and all doors are closed before you run it!

Apparently you can get replacement solenoids and valves for them.

Thanks Donh54!

I'll give that a try. So if I am understanding correctly = running the test procedure should give a more precise indication of where in the ACE system the fault is?

IMO that fault code might not be correct, it's one of the most common fault codes nanocom shows regardless of the real fault, the way to diagnose it better is to remove the ACE relay(R14), bridge the two middle parallel cavities in the fusebox(30-87), start the engine and read live inputs then post them here...i'll tell you which is suspect, probablty the transducer cos last time when i was trying to figure this out it gave me the DCV1 fault code as your's with the pressure transducer unplugged but i've seen this code oce when the real fault was the pressure control solenoid.... though it might be a coincidence and this to be the correct code...when it comes to ACE fault codes nanocom is a lottery but it can read correct live data but this is possible only with bridged relay cos as long as the warning is on the relay is open and the ECU misses the main feed so you'll not get real data.

anyway the DCVs are the two solenoids on the top of the block and both must have same 2.7 Ohm resistance, DCV1 is toward the front of vehicle

Edit: Just saw Sierrafery's post above - do his (proven) process. That should help you pinpoint it (or at least narrow it down somewhat)

Basically, it has a couple of accelerometers (one in the roof for sideways "yaw", and one on the chassis for fore and aft movement). These signal the ACE ECU what's happening, and it responds by sending signals to the directional control valves to increase or decrease pressure on the rams.

From the sounds of it, the ACE ECU is having trouble communicating with the dc valve. Could simply need the plug on the ECU cleaning out and reconnecting, or could be the dc valve is sticking.

Have you, or any previous owner, got any records of whether the ACE fluid/filter has been flushed/replaced in the past? The filter should be changed at 120K, and the actual reservoir and fluid should be replaced at 250K.

Fo future reference here are the correct readings from a well working system(vehicle sationary at idle on even ground) +/- 1 unit is aceptable:

1. DCVs (both) - .001A
2. Pressure control valve: 0 - .012A
3. Pressure sensor: varies between 16 and 19 but if it's out of that range the transducer is gone
4. Residual pressure: between 3 - 6 Bar but can be higher after the vehicle was driven or the ambient temp is low
5. System pressure: around 6 Bar fluctuating
6. Accelerometers: 0.01

for trouboeshooting purpose: the resistance of both DCVs(top of the valve block, DCV1-toward front; DCV2-toward rear)= 2.7 Ohm, pressure control solenoid(on the left side of block) = 5.7 Ohm.

***NOTE: To read the inputs while the warning lamp is on the ACE relay(R14) must be removed and bridged the two middle parralel cavities in the fusebox(30 - 87, relay's contacxt)

Thanks everyone. I'll try the tips mentioned and hopefully get closer to the source.

Which of these 2 are 30 & 87?
3 and 5?

Yes, 3-5