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Discussion Starter · #1 ·
I'm pretty sure I have power shorting to ground somewhere, which may be the cause of the ECM-6B00 and ECM-6300 codes I have on VIDA. I know I'm starting yet another thread for this issue, but I like to keep things separate with more relevant titles. Plus it makes it easier to find if someone may have the same issue or is able to offer input.

When I test the wires that are related to those codes (pink wire at B1 on the cluster and brown/white wire at B11 on the cluster) for ground they both show about 26 ohms (not sure if this is normal). After lots of testing, I eventually discovered that the e-brake sensor is what is grounding those out. When I release the brake, they go open circuit (or high resistance, at least) to ground.
I put the e-brake down and erased the codes and scanned again, the codes returned. So I don't think that's the issue.

Another thing I noticed is that when the PTC is connected, I'm seeing about 12 ohms to ground on the green/orange wire on the TCV. I know the PTC is heater, and it's supposed to create resistance, but is that resistance to ground at the TCV a problem that could cause it to limit boost? I tested another PTC and I got 9 ohms on that one. Does anyone know what the resistance on that wire should be?
This also travels to the fuse panel in the main fuse box with the large fuses, on the linked power side of all of them, so everything that's connected to those fuses is getting approximately 12 ohms to ground. This includes ECM B11 and B38, both power wires for the ECU. This is another question I have... is this acceptable?

Finally, the one I'm most concerned about... fuse 15 in the panel on the windshield cowl. This fuse is for the interior lights, glovebox light, and other things. When I open a door, I see about 10.5 ohms to ground. If I open another door, the resistance goes even lower... all doors open shows about 2 ohms. I see about 12 ohms if I open the glove box door and nothing else.
I know it's normal behavior for these latches to give a ground signal when opened, but should it be at that fuse? I feel like it's grounding some things out that should not be grounded. It's weird to me that a fuse would show any continuity to ground, but I guess I learned something new. Or there's something wrong with my car.

Some background for those who haven't read my other threads... I've had the two codes I mentioned at the top of this post since I got the car running. I have a Hilton stage 1 tune, and I'm only making about 8-10 PSI of boost... it should be more like 16. The boost is acting very strange too, sometimes it boosts lower, sometimes it seems to bleed off pressure, and other times it backs off from the 10 PSI peak and slowly tries to build back up. Now I haven't totally eliminated a boost leak as a possibility, but I found no leaks after multiple pressure tests and a smoke test.
I've recently started having the tach randomly go to 0, and occasionally get a check engine/ETS light combo when the ECU throws a new code (most recently a vehicle speed sensor code... no idea what that has to do with anything. The speedo has never had a problem). The interesting thing about the CEL and ETS lights are that they will "pulse" or flicker. Not quite a flash, but it looks like there's an issue with the wires making contact.
It's not the tune, I've already tried troubleshooting on the stock tune and there was no difference. Who knows, maybe my ECU is going out. I had the whole harness pulled apart under the fuse panel and there are no problems under there.
The next strange problem is that the ETM whines/buzzes. Sometimes very loudly, sometimes quietly, sometimes not at all. It's very sporadic, but it's definitely making noise. This is the third ETM I've put in this car, so the ETM is not the cause of the buzzing. The green/white wire will go to about 12 ohms to ground when the PTC is connected, but this issue persists even with the PTC disconnected (no longer grounding this connector).
 

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Discussion Starter · #2 ·
The ground may still be related to the B1/B11 cluster wires. I noticed it shows about 65 ohms to ground with the key in position 2 and the car NOT running. While running in position 2, it's open circuit to ground.

Now to start pulling fuses and see what I can figure out. If anyone has an idea, please feel free to chime in!
 

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Discussion Starter · #3 ·
So nobody here has ever had any kind of issue like this before? With my luck that's the case, but this is getting really aggravating... I think I have some strange issues, but no information to work with to confirm these issues. It feels like the universe is telling me I shoulnd't own this car.

Sorry... I usually hate when people start ranting like this but I need to get it out. This car has been a royal pain in my a** since I bought it a year ago, and I haven't been able to enjoy one drive in it. Shoulda never sold my 740...
 

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Discussion Starter · #4 ·
Well I've been driving the car since yesterday afternoon/evening, and so far everything has been fine. No tach issues, warning lights, or anything. Mind you I have done absolutely nothing.
Boost is still low, but I'm pretty positive that it's due to a hose leaking under pressure. I need to try to track that down, but I'm more worried about the car having another electrical episode.
 

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Have you checked for voltage drop or excess resistance in the charging system/battery cables? The 99/00 cars are notorious for having excess resistance in those cables over the years and the low voltage could wreak havoc on your ecu’s ability to control the engine.
 

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Discussion Starter · #6 ·
Have you checked for voltage drop or excess resistance in the charging system/battery cables? The 99/00 cars are notorious for having excess resistance in those cables over the years and the low voltage could wreak havoc on your ecu’s ability to control the engine.
I have, there is a 0.05V drop between the battery + and alternator B+.
 

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What I can say, is that I have only once experienced the dash going completely bongers (gauges showing nothing or random) and that was when I had a bluetooth OBD reader attached to the OBD port. It may have been there loosely or something causing a connection issue, or then it wasn't even to blame... I removed it, restarted, and everything was ok again. Probably gives you nothing, but that's what I have experienced.
 

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Discussion Starter · #8 ·
Interesting.

I've driven the car about 350 miles without issue, but the CEL/ETS lights still flicker when I first turn the car on (when they light to test, they aren't on for any codes). Codes are still present (6B00 and 6300) and the boost is still acting up. But the boost is unrelated I think, I can hear a boost leak. Which from what I can tell is coming from the IC weep hole, which is a little odd.
 

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Im lacking in the electronics diagnostics. But you may want to try this to track down any hose leaks. The paper in the top of the pump is where you would put a cigar. Or you can hook up a compressor to this contraption as well and listen for leaks. Everything can be bought a harbor freight. The plug you can get at home depot. Disconnect the turbo intake pipe after the MAF and install the plug. Works well, i felt the cigar smoke test worked best.

 

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Discussion Starter · #10 ·
Im lacking in the electronics diagnostics. But you may want to try this to track down any hose leaks. The paper in the top of the pump is where you would put a cigar. Or you can hook up a compressor to this contraption as well and listen for leaks. Everything can be bought a harbor freight. The plug you can get at home depot. Disconnect the turbo intake pipe after the MAF and install the plug. Works well, i felt the cigar smoke test worked best.

That’s a good setup! I have a similar plug piece that I glued an air hose fitting into, then plug the intercooler hose just before the plastic hose to the throttle body. It works well, but I can’t pinpoint the leak. It sounds like it’s just coming from the weep hole in the bottom of the intercooler.
 
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