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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
I am guessing not because my scope on came with the two probes. They only have 1x,10x attenuation ability.
Correct. See your gain in the specifications:
200mV～50V/div@x10 probe
So you can do 50V on 10x but without 10x you can only do 5V (fortunately CKS and CPS power). Anything higher make sure you use 10x (like the 12 volt stuff).
Ok, here is where I'm at currently. I see that "negative" spike in the cam sensors wave, on the last pulse of the Crank sensor. Does this mean the cam sensor signal is dropping out on that last wave of the crank signal? I'm very interested in understanding what we are seeing here, please do explain if you would be so kind?
Last edited by 4x4jeepmanthing; 02-14-2024 at 03:12 PM.
Hahaha what's a little pun for a learning thread.
Here is how I had hooked up our test to the PCM:
The ground is just some new wire that I tightened into the battery ground.
IDK what that is. It was actually occurring the last time you analyzed this:
but I think the location in this image shows that it's somewhat independent of CKS signal. Yet, also in this image there's extra activity in the CKS at the same spot.
I am grounded directly to the battery on todays reading. IIRC the previous test on the old thread, I replaced the Cam sensor and that "fixed" the issue, or allowed the jeep to start just fine until now. Even when I took the Jeep in to a shop for diagnostic, the previous thread, they were unable to find what the issue was.
On the scope reading you posted for the older thread, I believe I grounded with pins for both signal and ground on the plugs.
Last edited by 4x4jeepmanthing; 02-14-2024 at 03:43 PM.
...the previous test on the old thread, I replaced the Cam sensor and that "fixed" the issue, or allowed the jeep to start just fine until now.
I think there's 2 choices:
Those extra spikes are artifact and the problem is somewhere else; or
Those extra spikes are real and ECU REALLY doesn't like seeing -0- volts where there shouldn't be. If we can't clean up the signals by reducing the sample rate, including those spikes, and given the history of solving the issue before (would've been nice to get waveforms when it was running, but oh well), IIWM I'd shoot the Parts Cannon at another camshaft sensor.
02-14-2024, 02:53 PM
