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Smoking pmd

PMD's are never guessing. Sorry for misunderstanding. ECM's are guessing and many have replaced entire IP's over bad PMD's.

We should be on page 5 here of the flowchart. Edit: "test bench" means when IP on on engine: the voltmeter is on the windshield so you can see it and cranking. 30 Seconds with 2 min to cool is all the starter is worth before it starts to melt.

I assume the smoking from the PMD area has stopped?
 

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Never assumed a PMD as good even if it is new.
There are a lot of junk part out there.

I checked that seller at Amazon and from the pictures, it looks like it is unbranded PMD.
Looks like Flight System but the Chinese can make anything to look like something.

I would at least exchange it and see if it is the PMD before tearing up the IP.
Just saying.

Or get a known brand like Flight System.

Now hopefully, the smoking PMD has not cause domino damage into other parts.
 
Jr5150,
To rule out the fuel issue you suspect, you should be able to bypass operate the lift pump to push the fuel to the injectors. With my '95, I can pull a relay and cross two terminals to operate, but I can't remember if your '96 is the same way. (truthfully, I have one of Leroy's harnesses, so I just hit a momentary switch, but before that, I would do the above).

I'm not sure you were to the point of discovering the lack of fuel to the lines when we talked, but that's an interesting scenario.
 
WarWagon said:
PMD's are never guessing. Sorry for misunderstanding. ECM's are guessing and many have replaced entire IP's over bad PMD's.

We should be on page 5 here of the flowchart. Edit: "test bench" means when IP on on engine: the voltmeter is on the windshield so you can see it and cranking. 30 Seconds with 2 min to cool is all the starter is worth before it starts to melt.

I assume the smoking from the PMD area has stopped?
Click to expand...
WarWagon said:
PMD's are never guessing. Sorry for misunderstanding. ECM's are guessing and many have replaced entire IP's over bad PMD's.

We should be on page 5 here of the flowchart. Edit: "test bench" means when IP on on engine: the voltmeter is on the windshield so you can see it and cranking. 30 Seconds with 2 min to cool is all the starter is worth before it starts to melt.

I assume the smoking from the PMD area has stopped?
Click to expand...
War Wagon,
I posted some screen shots of some readings I took. Would you mind taking look and tell me what jumps out at you? Some of the voltages changed when cranking and some changed with the key off and stayed on for about 25 sec then went to 0v.
Thanks
 

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There is also the IP harness under the intake where the PMD hooked up into.

I would at least replace that harness.
I suspect the smoke probably burn that cable but OP needs to check it.
 
"No voltage" IMO means "voltage out of range". With the pump cam reference voltage way out at 10V I would suggest you disconect the optical sensor and try to start the truck or look for glow plug hole fuel mist if you have them out. You will use the full 30 seconds of cranking. Optical sensor is the plug on top of the pump. Also check for an Optical Sensor filter harness aka a black box 4" into this harness with yet another plug. (Am I reading that correctly 10V?! For something that should be under 1V? One volt has TEN volts?! ) If the 10V is correct this is indicating something has shorted to a 12v source: although possible it's rare and a 10.0 on the weird scale.

I would also retake the 10V readings with only the PMD disconnected.

" some changed with the key off and stayed on for about 25 sec then went to 0v"

We don't care about key off voltages. Ignore them. FWIW: The ECM stays "alive" for around 30 seconds after key off. If you key back on in the 30 seconds the SES and STS lights are random for a bulb check. It can also set a ghost APP, throttle pedal code, on 1995's.

To take another reading you should wait 30 seconds after key off for the ECM to "shut off". Then Key On and try the next reading.
 
I decided to remove bottom plenum so I could get a better look at the wiring harness to the IP. Everything looks ok with the wiring. With the ip exposed is there anything I can check?
 
Jr5150 said:
I'm doing continuity tests from plug to harness. Checking each wire for opens or shorts and any fuses along the way.
Click to expand...
I also managed to get the old burnt pmd out and do some engine cleanup in the process.
 
JMJNet said:
Pictures?

That burnt PMD may burn the IP also?
Click to expand...
Any way to tell if it is? I'm reading 0 ohms across the IP solenold red/blk.
 

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Jr5150 said:
Any way to tell if it is? I'm reading 0 ohms across the IP solenold red/blk.
Click to expand...

Only thing I could find indicates low resistance like 0 ohm on some things. I could not find a resistance check table for the DS4. You will have to test another pump or maybe a member here can ohm out a DS4.

Can you confirm if I am reading your notes of Ten Volts correctly?

It makes a big difference in what you are looking for if it's really 1 volt. Ten volts is a short to positive, One volt is: low resistance aka short, low supply voltage, or high resistance burned up wire somewhere.

You win the PMD carnage thread BTW.
 
If I'm reading a coil winding on a solenoid to the ip, I can see it being a low impedance.

The 10 volt reading is ac voltage, so not sure what is generating that?

After taking the bottom plenum off and checking wiring, I'm not sure where to go from here. Do I take the ip out and have it tested or can it be tested where is, or put it back together. This things gonna make an old man out of me🤔
 
I got ahold of a teck 2 and i'm getting P0215 engine shut off solenoid control circuit and p0238 turbo high voltage.
 
Sounds like it could be wiring harness issues from your little PMD meltdown. Iirc, both of those circuits are in that harness bundle that runs under/through the intake manifold. Although Turbo Voltage High can indicate a bad Turbo Control Solenoid as well. Iirc from earlier in this thread you checked/tested the Fuel Shutoff Solenoid atop the IP and it was working fine, so that code indicates a wiring harness issue most likely.
 
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