I was doing a compression test today and when I got everything hooked back up, the car won't start. The fuel pump isn't turning on, so I'm assuming the DME is having issues. I tried to connect to INPA, but I'm getting the error IHF-0009: No response from control unit.
Do I need to re-align the DME? I was able to get to the Activate button in the EWS menu, but clicking Activate did nothing. I'm not sure if I'm doing it right though. I've done it before, but I can't remember how.
Please help!
2003 540i/6
Most likely, you have electric connectivity issues.
With key in position 2, INPA must connect (you'd see the two buttons : battery and ignition highlighted) before you can attempt anything.
Assuming the INPA cable is good -you did use it to connect before--
Last edited by Chedley; 04-21-2019 at 08:46 PM.
I used the cable successfully right before doing the compression test. I am able to access other modules through INPA, but I cannot access the DME.
2003 540i/6
I'm going to charge the battery. We we're cranking a lot screwing around with the compression tester.
2003 540i/6
Dumb question but did you reinstall the fuel pump fuse? I’ve had a few moments like that where I got no start after a compression test because of leaving that fuse out.
1995 525i 5-speed - Thread
Haha, not the first time, but then I remembered and put the fuse back.
2003 540i/6
Check the DME Ground wires.. On the 6 cyl, they (3 or 4 wires) are bolted to the chassis right below where all the wires enter the DME box in the engine. I assume the 8 cyl is the same. This area isnt' too far from where you were doing the compression test - at least on 4 of the cylinders.
I had this problem and it was the DME ground wires.
I'll check that when I get home. Thanks.
More info:
We were using the threaded adapter as well as the bung attachment for the compression tester. When I was holding the gauge in place, the green ground wire on cyl 7 was resting against my hand and I could feel pulses/shocks. When I moved my hand, the braided wire was loosely on the stud and it sparked. The braided wire did this on the other bank too.
I also checked the fuses for the DME this morning, and they all looked good.
2003 540i/6
Yeah -- some compression test instructions say to pull the relay to kill the spark too, in addition to the fuel pump. I assume the spark was because you still had some coils and plugs connected. I wouldn't think that the bad ground would cause this problem. Probably low/dead battery. Seems strange that so many people here are having these problems. (Never happened to me and I've had dead batteries often enough.) Glad GG gave us that thorough explanation.
It looked like such a straight forward job, I didn't even bother to look for instructions. Definitely should have though. I took the DME apart and with the help of GG, he noticed that one of the ICs was burnt up.
Here's a pic of what the IC normally looks like. (it's the one with the 25 sticker on it)
thumbnail_image1.jpg
Here's mine
Capture.JPG
2003 540i/6
Bummer. If that's bad there are probably other connected parts that are bad too.
Time to get another DME.
Looks like one of your caps is swollen also?
So what is the correct process for performing a compression test? Remove both main and fuel pump relays and jump the starter?
demet
New DME is in the mail now. I'm going to try to get through all 147 wires going to the DME to see if anything is shorted out. I think while I'm in there, I might re-route my wires like you did to yours, Jim.
Yeah, I saw that cap when I was taking pictures. As far as procedure goes. If I were to do it again, I'd either look for a proper write-up (TIS or forum post) or I'd disconnect the coil connector on the dme, and tighten the braided ground down to the valve cover, rather than leave it loose. -I'd most likely look at how to do it properly though.
2003 540i/6
ive just left the coils unplugged, relieved pressure on the fuel rail, pulled the fp relay and held the throttle body open in doing compression tests previously with no harm.
Good plan. I'm sure I have more pics than what I posted when I did it.
You'll need to lengthen some of the wires.
The pass side wires that come out of the front side of the wire box for the starter and oil level sensor were moved to the rear of the box. That allows both boxes to be individually removed.
It would be interesting if the new unit helped with your original rough running problem. Hope so.
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