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Discussion Starter · #21 ·
Next UP is a trace - A KNOWN BAD trace because I saved this before made any correction.

Whats significant here is where the CamTDC pulse appears on the trace. This is what needs to be timed with the actual TDC on the Crankshaft position sensor on the bottom (it is not in this picture). Note the 1-3-1-2-3-2 Cam pattern and this is the first "knob" of the 3 which pulls the signal down to zero.

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Discussion Starter · #22 ·
My apologies for getting the extra OPDA picture in there.

Next thing I needed was some indication where TDC for the crankshaft was - the REAL TDC of the engine.

I got a known good waveform from a running Jeep on the Scanner Danner forum. Fast forwarding a bit on this...I've drawn a line from the CAM TDC point down through the Crankshaft Position Sensor trace.

As you can see here is it's aligned with the middle of the last pulse before the crankshaft goes LOW for 2 cycles...

That tells me that pulse is what I need to be aligned with.

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And zoomed in for clarity:

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Discussion Starter · #23 ·
And..let's stick to zoomed in now that everyone knows what's what...

After all of my parts changing - here's where I was - close but not close enough:

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Quick Discussion Point - The Crankshaft generates 16 pulses, plus a 2 pulse-long LOW pause and the 16 pulses plus a 2 pulse-long HI pause in 1 rotation.

16 + 16 + 2 + 2 = 36.

36 x 10 = 360 degrees...

SO...according to me (and probably everyone else already knew this)... Each Crankshaft Pulse is 10 degrees...

In short - my signal was about 10 degrees out of time with the reference.

Another Note: I don't know how tight a new OPDA meshes with the Camshaft gear. My new OPDA in the 163,000 mile cam has a bit of slop...it's the width of one of the knobs on the OPDA wheel.

I dialed it back counterclockwise slightly and came up with the following. It brought it to the "foot" of the pulse and the error went away.

Notice it did not make it quite into the pulse - but it seems it's close enough.

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Discussion Starter · #24 ·
Next Steps:

I feel like I'm on the shaky edge and will be dialing it back a bit more to hit the mid-pulse of the Crankshaft sensor.

Wear on my OPDA gear will make it tend to drive more into that long pause area.
 
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Discussion Starter · #25 ·
And final data points -

There is a past thread and set of posts that demonstrated there is signficant differences in the signals generated from after-market Camshaft sensors vs. the Mopar ones.

I can confirm that the Duralast and Crown are very different.

Here is the OEM vs. the other 2. Note how narrow the OEM pulses are...actually they mimick the pulses of the Crankshaft.

The narrow gap between pulses on the aftermarket devices makes it that much more difficult to get the timing correct.

If you follow ONLY factory procedures, I can see that these can be considered faulty...and in fact are not to the same spec.

I'm currently running on the Duralast and that's what's shown above.

Here are the comparisons.

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Discussion Starter · #26 ·
That's all I have for now. I'll tie this up when I finish messing with my timing.
 
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Discussion Starter · #27 ·
Oh bummer...the middle graph above for the Crown unit's notes... It's late...

Here is the Crown....


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Discussion Starter · #30 ·
Hey Folks. My apologies for not getting back here. Troubleshooting came to a standstill for a few months due to work and the hot summer.

Here's an update and plan -

Reclocking the OPDA seems to have produced a false success.

At about 145 miles the code popped back up. I experimented a bit more with adjusting the OPDA to see if there was a sweet spot, but right now it regularly gives the P0340 in about 8-15 miles and not so often a P0344. No other codes.

I set up a new plan and just got that underway.

Trading money for time I ordered and installed a WranglerFix PCM. Ran that two days ago and the P0344 and P0340 returned at just about the 8 mile mark. Also picked up a code P0133 (slow O2 sensor) that my original PCM does not produce. I'll chase that oddity later..

The upshot is the PCM is not the problem.

That's great because now I know to again refocus on the harness. Here's what we know about that:

1. The connector has been cut off (previously) and i have a direct new wire running on the signal lead directly to the computer. That terminal is not shared with anything else.
2. Similarly, the ground to the PCM also spliced directly into the ground pin on the PCM with a new wire. This is also connected to the grounds for the Crank sensor, MAP and one other.
I'm not as concerned about those as if they short to ground..it's simply more ground contact. Only issue is if a sensor is backfeeding on that wire which isn't likely.
3. The +5 lead, however, provides power to the other sensors. If it shorts, it will drop the voltage and the sensor signals will fail. I cannot put a dedicated wire from the Cam sensor to the PCM for the power - it must be tied to the other or they will not have power.

Next steps:

1. I retimed the OPDA by aligning the engine back to TDC, installed the pin and tightened it down per the manual.
2. I'm getting a new connector for the Cam Sensor - just because. Maybe it was probed at the dealership and perhaps it's not making good contact. It looks good.
3. I'm going to do an end to end track on the +5 lead. Splice 127 is along the back of the valve cover, very hard to expose but I need to see if something is shorting there, or on the wires to the VSS, MAP, Crank Sensors.
4. If I can't find an issue..and I've tried...I'm going to cut the +5v lead at each of the connectors, make a separate harness to connect them all to the computer and hope to claim success.54. If that fails...I'll do the same with the grounds.
5. this will all be done with the original PCM...
6. If that fails, I'll replace the VSS in case it has an internal short. It's the only sensor on the chain that I hadn't replaced and test. Cam, Crank, Map sensors have all been tested with new ones.

I may come and go but I will post my solution...up until I have my LJ towed off...(never)...
 

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Hat’s off to your persistence. At least you have a PCM as back up now. I wish we had fresh ones available. I would have been in fetal position already with all the wire chasing.
 

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What Norm said - your persistence is really inspiring!

My previous LJ had a bypass wire from the PCM harness to somewhere in the 42RLE (tranny) area, never did chase it down out of curiosity. The wire was likely added by a dealer in response to some sort of an issue. Apparently wire harness problems aren't that much of an oddity.
 

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Discussion Starter · #33 ·
That "seems" to be the case here as well, John...

Weekend update.

1. Installed new Cam Postion Sensor connector (harness side).
2. Cut the yellow/pink +5v wire about 8 inches back at the Cam sensor, MAP sensor and VSS
3. Temp spliced in new wires to each, tied them together and connected to the PCM. Vehicle harness is severed for this circuit.
4. Cleared the errors from the WranglerFix PCM, still have the Crown Cam Sensor installed.
5. Took it for 2 drives, 6 engine restarts totaling 45 miles.
6. No error codes, no glitches and a fine running machine throughout.

Not calling it done as I've gone this far before... but it's be awhile since it would go this far.

If this resolves the issue, I'll be reinstalling the original PCM and cam sensor and seeing if they'll play well together...

Oh..and lacing the new wiring and rewrapping all harnesses...
 

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Discussion Starter · #34 ·
Oh..and to correct previous errors - S127 ties the grounds together. S129 ties the sensors +5 leads together. Both in the same impossible area to work in by the back of the valve cover/head.

And the Crank sensor does not share the +5 with the others. I said previously that it did.

The wiring diagrams and location diagrams on the often maligned Alldatadiy are actually pretty good as is the rest of the manual for the Wrangler. They've been accurate and invaluable for this effort.

I've had variable results from Alldatadiy depending on the actual vehicle. I'd highly recommend for Wrangler maintenance...at least the 2005 edition. Looks like direct copy from the FSM.
 

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Discussion Starter · #35 ·
I believe I'm in the "resolved" zone. I've put a ton of miles on the rig and zero issues.

Unless something rears its head later...the problem seem to be clearly with the wire harness.

Current setup:

1. Bypass wires in connecting the yellow +5v wires in to the MAP, VSS and Cam sensors to the PCM.
2. Crown OPDA and Cam Sensor installed
3. Wrangler Fix PCM.

Item 1 is what brought the current resolution. I have not been able to identify the actual harness fault.

I will be lacing in my bypass wires and making permanent splices today. I got a replacement yellow wire from a new trailer harness I had laying around, so my sense of order on colors will be intact.

Since this started as a request for a waveform, I'm going to close the loop. Below is the waveform from my now working Jeep. Since the Wrangler Fix PCM had to learn the CAM/Crank relationship, a reset was not done.

Later...maybe much later...I intend to swap back in the original PCM and see how it likes the Crown sensor. It may still require a relearn.

I also want to swap back in the original Mopar sensor to see how the Jeep reacts to the narrower OEM waveform.

For now, I'm not messing with it...going to wheel this fall.

Here is the waveform that I'm going to declare is from a running Jeep with a Crown sensor. Ignore the vertical cursor...it's on the wrong pulse. Previous waveforms indicate the correct pulse for the cam sensor when the crank is at TDC.

Font Rectangle Musical instrument accessory Electric blue Parallel
 

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Is the yellow trace the clock? I forgot what protocol this is.
 

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Discussion Starter · #37 ·
Top trace is the crankshaft. Middle is cam and bottom is just the 5volts provided to the sensors.

Compared to the reference trace I received from the ScannerDanner forum, my new trace matches that one exactly.

The camshaft pulse lines up with the same part of the crankshaft pulse, so now I'm comfortable saying this represents proper relationship between the two.

Here's my same trace with a yellow line added
Rectangle Font Parallel Screenshot Pattern
indicating the cam/crank relationship for comparison.
 
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