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Discussion Starter · #1 ·
I'm now on my 3rd VVT solenoid, still have the code coming and going. ECM-6440 signal too high. I've checked the wires, and I soldered the wires in correctly, so that's not an issue (used solenoid from a newer 2.5T, I wasn't going to pay for a new one if I don't know if it's the problem).

I can't figure out what's wrong... it runs pretty well overall. The standard OBD2 code showing is P1656.

I'm really trying to figure this out before selling the car, but I just can't get anywhere with it. Signals are all good, I checked continuity between the VVT solenoid and ECM A13 and it's all good, and VIDA shows the solenoid is doing what it's supposed to do when I watch the values changing.
Checked the cam sensor, some dope cut the wires at some point and twisted them back together (couldn't find the connector around the front of the head?) but I cleaned that up and it doesn't seem to be a problem.

Resistance on the cam reset valve/VVT solenoid shows around 5.6 ohms... a little higher than spec, but I checked SEVERAL in the junkyard and they were all about the same.
 

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Is it a permanent fault? Comes back as soon as you clear it?

Have you checked the wiring that runs from the vvt solenoids across the top of the cam carrier? Over time those wires can rub or be pinched when the plastic cover is re-installed. We've dealt with this on a good handful of occasions.
 

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Discussion Starter · #3 ·
Permanent fault, yes. When I cleared it, I turned the car off and back on. After running it for a few seconds, I turned it off and restarted it again, then checked the codes and it showed pending. Refreshed it then it was permanent. On VIDA, it shows permanent as well.

I've checked pretty much all the wiring, I fixed some rubbed through areas on coil wiring, but wiring for the solenoid was in tact. I'll check more closely at the corner of the cam cover today, I wouldn't be surprised being that the wiring gets very brittle.
 

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Discussion Starter · #4 ·
The signal wire is all good, there was one spot where it was nicked, and after fixing it and clearing codes, it's back after a short drive.

I noticed when I start the car and hear the first solenoid/relay click (I assume this is the VVT solenoid) I hear a slight whining/gurgling sound, then after the second click a few seconds later, it goes away. Something's not right, and I can't figure out what it is.
 

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Any continuity to ground on either wire? Use gator clips and a wire piercing probe. Wiggle wires across the top of the engine and see if ya get the audible beep. Were all the solenoids you tried new or used? Spec is 3.7 on the solenoid and although 5.6 isnt that much more...it IS out of spec, so you may have to eliminate that before chasing wiring. And your sure you've got the wires in the correct orientation in the vvt connector?
 

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Discussion Starter · #6 · (Edited)
Any continuity to ground on either wire? Use gator clips and a wire piercing probe. Wiggle wires across the top of the engine and see if ya get the audible beep. Were all the solenoids you tried new or used? Spec is 3.7 on the solenoid and although 5.6 isnt that much more...it IS out of spec, so you may have to eliminate that before chasing wiring. And your sure you've got the wires in the correct orientation in the vvt connector?
I am 99% sure the wires are in the correct positions, I couldn't find much info from searching, but based on diagrams I'm pretty sure they are correct.
I don't think there is continuity to ground on either wire. All solenoids I've tested have been used, but I just find it highly unlikely that they are all bad.

From the little I can find online about this code, I'm going to double check that the cams and crank are properly aligned, but I feel like this code was present prior to changing the timing belt, so I find it unlikely to be the problem.

I'm also curious about that second "click" sound I'm hearing, I feel it's not supposed to do that twice. My 2003 only does it once. It sounds just like the AC clutch cutting on/off, but I'm pretty sure it's VVT-related. It'll click that first time, then a few seconds later click again.
 

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PER VIDA

Check the camshaft reset valve resistance between #1 and #2, resistance should be approximately 3.7 Ω.

Check the signal cable between engine control module (ECM) #A13 and camshaft reset valve #2 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault:Short-circuit to supply voltage. Permanent faults .

Remedy as necessary

Other information:
To connect the breakout box, see Connecting the breakout box .

To access/replace the camshaft reset valve, see Variable valve timing solenoid, replacing .

With the ignition on and the camshaft reset valve connector disconnected the voltage on connector #1 should be approximately Ubatt and at connector #2 it should be a pulse modulated signal with a peak voltage of approximately Ubatt and with a frequency of approximately 250 Hz.



**Red/Yellow wire should be in Pin #2, Green/Grey Pin #1..

After looking at the wiring diagram - If your wires are in the correct position and the vvt valve is known to be good - Try unplugging the Evap valve, reset codes and see what happens and report back.
 

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Discussion Starter · #8 ·
I'll give that a go. I checked for continuity to ground, and there is about 13.5 ohms on the green/gray wire, which is typical due to it being on the same circuit as the PTC (went through what I thought was a short to ground issue on my V70R that turned out to be a weak B+ fuse box cable). I'll test the evap valve shortly.
Wires are also correct.

However I think the solenoid may be incorrect, even though I had heard previously that they are all compatible. I have PN 8670422 (superseded by 36002686) and that appears to only be compatible with 2002+ models (which is odd to me) but according to VIDA, the correct PN for this 2001 is 36002695. I think this one came off a 2005 or 2006. Do you think that this could be the problem?

Update... probably not the problem, my 2000 R has the update kit with the pig tail, and the solenoid has the same PN... 8670422. It seems that the PN difference is due to 3600695 including the pig tail.

I also double checked the timing marks, all is well there.
 

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Discussion Starter · #9 ·
Unplugged purge valve, no change. Did you mean the evap valve on the fuel tank (or both being that they're on the same circuit)? I can't even find that for some reason.

Torque app also doesn't show any reading from the front O2 sensor, but the rear is working fine. No codes for the O2 sensors. Do you think it could be bad? I've already checked the connector, seems to be seated.
 

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The Evap valve on the shroud and the VVT solenoid share the same green/grey wire so I was hoping it may have been the cause of the problem...02 sensor isnt on that circuit at all. Green/Grey is fused and the other one is the signal wire directly from the ECM no fuse in between. The issue we're having is the Signal wire (red/yellar) is shorted to supply voltage(signal too high) or the valve is defective, according to the code, this comes directly outta the ECM. So, If we're SURE the solenoid is good, the power wire is (should be since the fuse is good), and we've eliminated the other item on the circuit (evap valve), maybe lets try running a new wire from the ECM to the vvt solenoid?

Maybe I asked this already but neither wire have continuity to each other do they? (with solenoid unplugged)
 

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Discussion Starter · #11 ·
The Evap valve on the shroud and the VVT solenoid share the same green/grey wire so I was hoping it may have been the cause of the problem...02 sensor isnt on that circuit at all. Green/Grey is fused and the other one is the signal wire directly from the ECM no fuse in between. The issue we're having is the Signal wire (red/yellar) is shorted to supply voltage(signal too high) or the valve is defective, according to the code, this comes directly outta the ECM. So, If we're SURE the solenoid is good, the power wire is (should be since the fuse is good), and we've eliminated the other item on the circuit (evap valve), maybe lets try running a new wire from the ECM to the vvt solenoid?

Maybe I asked this already but neither wire have continuity to each other do they? (with solenoid unplugged)
Right, I didn't want to get wound up chasing my tail with something that's likely unrelated. I may just try to run a new wire, fortunately it wouldn't be too hard to get it from the ECU to the solenoid.

Last I checked, the wires are not showing continuity to each other.
 

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Discussion Starter · #12 · (Edited)
So... double checked resistance on the solenoid. 4.6 ohms, less than I thought. I think the original was 5.7.

I cut back the wire and twisted it straight to the solenoid just behind the connector to test. CEL went off momentarily, but came back on next startup. I don't think the wire is the problem... now to fish it back through the loom...

Anyway, I also checked the ECU grounds, all good. I thought this could be a ground issue, but I don't think it is.

There's about 480 ohms between the two wires on the solenoid.
 

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Ever have any resolution to this? Im having the exact same thing go on and its driving me f****** nuts. Ive tried like 8 diff used volvo solenoids so unless I’ve got 8 bad ones in a row its gotta be something else. Also my values in vida for the exhaust camshaft reset valve is stuck at 7.84% and camshaft shifting angle exhaust stuck at 0 degrees. Meaning they dont move off those numbers at all. Help please ANYONE!!!
 

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Discussion Starter · #14 ·
I had gone through a few used units too, I'm sure there was something else going on with that car. I ended up running new wiring from the ECU and everything... nothing fixed it. I think the VVT hub or cam sensor may have been messed up. I sold the car before I could fix the problem.
 
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