BMW X5 randomly loses Idle motor data, causing loss of DSC, ABS and engine torque
Hey guys! Hope everyone had a safe and happy holidays/ New Years!
OK, this 2002 BMX X5 3.0 will drive fine for periods of time, and then randomly the dash lights all come on, and the car loses ABS and DSC as well as a engine torque reduction. Every time this happens I get fault code 0000D3 (DME) Idle Speed Control Valve Mechanical Fault. I checked the wires to the idle valve and I've got 2.4v, 12v (battery) and 1.9v on the three wires, both when the code is present and not.
First tried a new Vemo idle control valve, cleared adaptations, with no change. Exact same situation, sometimes after 3 minutes of driving, sometimes 15 minutes.
Since I can pretty safely eliminate the Idle valve now, and I have power/signals at the wires, (admittingly I haven't yet checked the wiring diagram to see if this is the correct voltage) I thought I would try a sofware update on the DME. First tried with Autel for speed purposes as customer was waiting. Autel didn't have an option to program control units, only coding (which failed) and car key memory. So I tried ISTA P, ISTA wasn't able to read the VIN, possibly due to age, also couldn't read the vehicle order. So I had to stop there.
At this point I'm leaning towards DME being at fault here… I'm having the customer come back next week so I can go more in depth, and check for bad fuses/ connections etc.
I thought I'd throw this out now, in case anyone has seen this before or had some ideas for me.
Perhaps ISTA P just doesn't work on cars that old, maybe same for programming with Autel, I'm not sure.
Here's the codes that pop up each time.
Make sure the intake boot is not torn. I have seen several issues with the intake boots on these vehicles. Some of the rips may not be to obvious until you really twist or bend the boot.
Thanks Richard. Can confirm boot is 100% good. I had it off when replacing the idle controller. I've smoke tested the engine/intake and it's tight as well.
I've seen these symptoms before on a newer X5 and a newer 2012 5 series sedan. Both had defective alternators that were previously replaced with aftermarket “compatible units”. Live data log showed a drop to 8-9 volts momentarily and lit the dash up like an xmas tree. Similar codes generated, could be a starting point. You need to externally measure the input voltage to the DME to detect the…
What are the adaptations? Additive and multiplicative. Quite often a torque reduction code on that chassis the air mass sensor unless you get a code for idle control valve and tstat, then it needs a harness. I’ve done several harnesses on e53
I've done harnesses on the V8's. You've had the 3.0 need them too? I don't remember the exact adaptations now, but they were close to 0. Maybe a couple %.
Yes. Quite a few. Got one coming next week. Every single one had persistent IAC,AMM and tstat codes. There’s a voltage drop somewhere in the harness.
Hey Mickey, I've found a TSB regarding the engine wire harness for this vehicle, and I've got the corresponding DTC's for that. I think you were right on with the harness. Have you ever looked into where the harness fails? I've informed the customer, but because of the large price involved we're going to apply contact enhancer at the DME connectors as well as the ICV connector, to see if…
I’ve heard from fellow bmw specialist some success stories. I‘ve dissected a couple of harnesses and wasted hours trying to find the culprit and the only thing I found is that my patience is declining at the same rate as my hearing. At the end, “ no good deed goes unpunished “. Good luck and Happy new year.
I have an E53 in the shop I can see if ISTA will read the vo on it for you if you would like. I do remember with Inpa and kcan cable you have to short or open two wires to communicate with older vehicles.
Scope the pins at the idle speed control valve and get the problem to happen. You should have battery voltage on one pin and then the other two pins are what the DME ground controls with its internal transistors to either move the idle motor open, close, or hold at some intermediate position. If the desired idle speed isn’t seen when it does this, the DME interprets this as a mechanical fault of…
Test the tension of the pins for both the Idle Control Valve and the Throttle body connectors. If they pass the test, clean them well and lubricate them. Load test the 12V pin on the ICV connector for sure. It should be a fused B+. Programming the DME should not make a difference on such an old car that ran well for some time but you never know. You‘ll need an adaptor for the obd2 connector…
Going to close this discussion… I ended up putting contact enhancer on every connection on the DME, and all associated fuses/relays/connections in the E box as well as the connectors at ICV, throttle, MAF, etc. Owner reported the Christmas tree on his dash hasn't returned since, after a week of driving. It used to happen consistently. If it happens again he will have to have the engine…