99 PCM replace/update
#181
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Disconnect the TCM first. That"ll take out the speed sensors. Test. Measure the resistance of the cam and crank wires to A4. Should be about 0.01-0.02Ω. If that's normal take new dedicated ground wires for the cam and crank and put them on as the only thing on A4. That'll take out everything on K167 ground.
#182
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Year: 99
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Disconnect the TCM first. That"ll take out the speed sensors. is this the only other thing i assume shares the A4 ground? Test. Measure the resistance of the cam and crank wires to A4. Should be about 0.01-0.02Ω. If that's normal take new dedicated ground wires for the cam and crank and put them on as the only thing on A4 (does this require cutting?) If not, just probe them into A4? That'll take out everything on K167 ground.
Last edited by 4x4jeepmanthing; 07-01-2019 at 08:40 PM.
#183
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both ckps and cmps were .06-.08 on 200 ohm setting. Same as before, that's the range all my signal, power ground ohms to pcm plug one. I did unplug the T.C.M.
#184
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Disconnect the TCM first. That"ll take out the speed sensors. is this the only other thing i assume shares the A4 ground? Test. Measure the resistance of the cam and crank wires to A4. Should be about 0.01-0.02Ω. If that's normal take new dedicated ground wires for the cam and crank and put them on as the only thing on A4 (does this require cutting?) If not, just probe them into A4? That'll take out everything on K167 ground.
Ooooh scary thought. If this does work then you have to go through that whole mess and figure out which sensor or circuit is causing the problem. Good luck on that.
After this really need the oscilloscope.
#185
CF Veteran
Time to regroup!
After rereading the thread, not only must this be a frustrating problem for you, but frustrating answering the same questions all the time!
Sorry for asking about the alternator when you mentioned that before.
Forget that. If
then maybe it's a little high cause the wires are in circuit, but wanna measure a 3 foot piece of that 16 ga. wire before you put it in?
Did you test the camshaft position sensor signal for voltage while turning the engine over (by hand to see if you get 5.0 +/- 0.25V and 0.0)?
You still got that 0.05 residual voltage on the crank sensor to address (when you were looking at reluctor windows). I really think that needs to be 0.0.
Did you already put in new devoted signal wires?
BTW when measuring voltage use the 20V range instead of the 9V. It looks cooler.
After rereading the thread, not only must this be a frustrating problem for you, but frustrating answering the same questions all the time!
Sorry for asking about the alternator when you mentioned that before.
Forget that. If
.06-.08 on 200 ohm setting. Same as before, that's the range all my signal, power ground ohms to pcm plug
Did you test the camshaft position sensor signal for voltage while turning the engine over (by hand to see if you get 5.0 +/- 0.25V and 0.0)?
You still got that 0.05 residual voltage on the crank sensor to address (when you were looking at reluctor windows). I really think that needs to be 0.0.
BTW when measuring voltage use the 20V range instead of the 9V. It looks cooler.
#186
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Year: 96
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unfortunately for testing purposes, disconnecting each sensors will throw code/s
I dont know which sensors can be disconnected and still allow the engine to start and run at all
have you done research on the P1391 code on NAXJA..and Google, to see if anyone has had a persistent code before?
after that it does come down to an experienced auto tech with expertise on a scope
I dont know which sensors can be disconnected and still allow the engine to start and run at all
have you done research on the P1391 code on NAXJA..and Google, to see if anyone has had a persistent code before?
after that it does come down to an experienced auto tech with expertise on a scope
#187
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Year: 99
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Time to regroup!
After rereading the thread, not only must this be a frustrating problem for you, but frustrating answering the same questions all the time!
it's been a year of this, but I very much appreciate yourself, Awg, and others that have helped here. There have been many good suggestions here that aren't found anywhere else and trust me ive looked.
Sorry for asking about the alternator when you mentioned that before.
Forget that. If
then maybe it's a little high cause the wires are in circuit, but wanna measure a 3 foot piece of that 16 ga. wire before you put it in?
but all the wires for cmps,ckps signal, supply and ground are within this range, that's a bit coincidental isn't It?
Did you test the camshaft position sensor signal for voltage while turning the engine over (by hand to see if you get 5.0 +/- 0.25V and 0.0)?
I believe I tried this many months back, I'll update my 2nd try. I do know ive used an analog meter to see the pulse when cranking/running, signal is coming from it.
You still got that 0.05 residual voltage on the crank sensor to address (when you were looking at reluctor windows). I really think that needs to be 0.0.
I'll have to look at this again, I think that was the lowest reading I got other than 0. I'll double check this.
Did you already put in new devoted signal wires?
no, I need to make sure i understand exactly what this requires, same with the ground wires so I don't screw up something if any of these are shared at the pcm.
BTW when measuring voltage use the 20V range instead of the 9V. It looks cooler.
After rereading the thread, not only must this be a frustrating problem for you, but frustrating answering the same questions all the time!
it's been a year of this, but I very much appreciate yourself, Awg, and others that have helped here. There have been many good suggestions here that aren't found anywhere else and trust me ive looked.
Sorry for asking about the alternator when you mentioned that before.
Forget that. If
then maybe it's a little high cause the wires are in circuit, but wanna measure a 3 foot piece of that 16 ga. wire before you put it in?
but all the wires for cmps,ckps signal, supply and ground are within this range, that's a bit coincidental isn't It?
Did you test the camshaft position sensor signal for voltage while turning the engine over (by hand to see if you get 5.0 +/- 0.25V and 0.0)?
I believe I tried this many months back, I'll update my 2nd try. I do know ive used an analog meter to see the pulse when cranking/running, signal is coming from it.
You still got that 0.05 residual voltage on the crank sensor to address (when you were looking at reluctor windows). I really think that needs to be 0.0.
I'll have to look at this again, I think that was the lowest reading I got other than 0. I'll double check this.
Did you already put in new devoted signal wires?
no, I need to make sure i understand exactly what this requires, same with the ground wires so I don't screw up something if any of these are shared at the pcm.
BTW when measuring voltage use the 20V range instead of the 9V. It looks cooler.
unfortunately for testing purposes, disconnecting each sensors will throw code/s
I dont know which sensors can be disconnected and still allow the engine to start and run at all
have you done research on the P1391 code on NAXJA..and Google, to see if anyone has had a persistent code before?
extensively, the only thing ive gotten is the diagnostic list and usually replacing the ckps solves the code, but not indefinitely. This why I'm trying not to just throw sensors at it with out some logical sign. If we see something that points to ckps is a good bet then of course I'll throw it in.
after that it does come down to an experienced auto tech with expertise on a scope
I dont know which sensors can be disconnected and still allow the engine to start and run at all
have you done research on the P1391 code on NAXJA..and Google, to see if anyone has had a persistent code before?
extensively, the only thing ive gotten is the diagnostic list and usually replacing the ckps solves the code, but not indefinitely. This why I'm trying not to just throw sensors at it with out some logical sign. If we see something that points to ckps is a good bet then of course I'll throw it in.
after that it does come down to an experienced auto tech with expertise on a scope
#188
CF Veteran
No that's fine. Since we're measuring within the circuit it's probably reflective of other stuff in the circuit. The only way to truly get an accurate reading of the wire is pull it out. Taking a known length and gauge of wire will allow us to see what your multimeter SHOULD be seeing, and that should be about 0.01. As long as we're not seeing something considerably more than that.
#189
CF Veteran
I dont know which sensors can be disconnected and still allow the engine to start and run at all
#190
CF Veteran
I'll have to look at [lowest voltage] again, I think that was the lowest reading I got other than 0. I'll double check this.
#191
CF Veteran
I mean, if we get an oscilloscope and all the peaks are nice and even at 5.xx and the base is 0.05, 0.1, 0.0, and whatever, then we're going to say oh look problem there!
#192
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Correct me if I'm wrong but a two channel can only see one sensor a a time correct? One lead on ground the other on signal?
#193
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I would try Dave51 latest suggestions, unplugging all the sensors except crank and cam.
also possibly be inclined to buy cheap CPS and CAM sensors to substitute
rewire, as suggested before, as a last measure
After that, I would go back to the scope technician, get prints of the expanded waveforms etc etc.
If he is not sufficiently expert to do that, you need to find someone that is...unfortunately, this is not common, and generally that person would be a qualified Electronics Engineer
also possibly be inclined to buy cheap CPS and CAM sensors to substitute
rewire, as suggested before, as a last measure
After that, I would go back to the scope technician, get prints of the expanded waveforms etc etc.
If he is not sufficiently expert to do that, you need to find someone that is...unfortunately, this is not common, and generally that person would be a qualified Electronics Engineer
#194
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https://www.ebay.com/itm/SainSmart-M...-/121590979073
Correct me if I'm wrong but a two channel can only see one sensor a a time correct? One lead on ground the other on signal?
Correct me if I'm wrong but a two channel can only see one sensor a a time correct? One lead on ground the other on signal?
But you're not thinking of getting that thing, are you?
#195
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presumably he had the gear and expertise to do at least a basic check...but perhaps he did not look close enough at the signals, or lacked experience to analyse them
remember I mentioned to not accept his offer of a refund?,,, I have found in the past that (most) automotive experts will give free/underprice time to help resolve an issue in such a case. I cultivate & groom them lol...as if I cant or dont want to fix it myself, its usually nasty, I always offer to pay for all advice time, in cash of course
In an ideal world, you would have another running XJ to compare (like my 59 digits off VIN spare '96 XJ)