Truck died, no WTS light, advice on troubleshooting
Thread Starter
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Tuned
Joined: May 2021
Posts: 363
Likes: 121
From: Montana
Truck died, no WTS light, advice on troubleshooting
Truck died on the highway on the home from work today, just turned off. Had happened a week or so ago, though fired right back up. Thought it was CPS, though today the truck died and when I pulled off the highway and attempted to restart it I didn't get a WTS light. All the dash lights fire up, just no WTS and no tach movement when attempting a start. Checked the PCM fuses, all good, swapped in another relay for the PCM I had in the glove box, all no go. Pulled the Hydra chip and put in the new CPS I'd bought a week or so as well. No change after any of these attempts. The fuel bowl heater has been unplugged for awhile now, so not related to that. Wifey had to come pull me home!
With KOEO I get 12V at the GPR feeding the PCM (I think this is correct?), though when I pull the 20A fuse (#19 under hood) I'm not getting any power to it. No power to #30 30amp mini fuse under dash either. AE scanner will not connect with the PCM (not surprisingly).
What else I can I check? Thanks -
With KOEO I get 12V at the GPR feeding the PCM (I think this is correct?), though when I pull the 20A fuse (#19 under hood) I'm not getting any power to it. No power to #30 30amp mini fuse under dash either. AE scanner will not connect with the PCM (not surprisingly).
What else I can I check? Thanks -
Cargo Master
Joined: Apr 2022
Posts: 3,188
Likes: 1,695
Need to figure out why it's not getting power to the #30 fuse inside. Pcm gets power from that fuse. That's the issue. Wasting time messing with the cps.
One of the small wires will have power on it. That doesn't fee power to the pcm. The pcm ground the other small wires turning glow plugs on.
One of the small wires will have power on it. That doesn't fee power to the pcm. The pcm ground the other small wires turning glow plugs on.
Thread Starter
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Tuned
Joined: May 2021
Posts: 363
Likes: 121
From: Montana
Need to figure out why it's not getting power to the #30 fuse inside. Pcm gets power from that fuse. That's the issue. Wasting time messing with the cps.
One of the small wires will have power on it. That doesn't fee power to the pcm. The pcm ground the other small wires turning glow plugs on.
One of the small wires will have power on it. That doesn't fee power to the pcm. The pcm ground the other small wires turning glow plugs on.
Cargo Master
Joined: Apr 2022
Posts: 3,188
Likes: 1,695
Does it blown the fuse or now power at all going to either side of that fuse when you check it? What abiut other fuses in same panel are they getting power?
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Thread Starter
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Tuned
Joined: May 2021
Posts: 363
Likes: 121
From: Montana
I take it back, just rechecked power at #30 and it is getting power. My multi meter probes were too fat, checked it with little jumper wires and it is getting juice. My PCM might be toast.
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Tuned
Joined: Jan 2023
Posts: 396
Likes: 171
Check voltage, key on, on the brown/white wire on the exhaust back pressure sensor, or the map, or icp whichever is easier for you.
It should be 5v.
If it is not unplug accelerator pedal sensor, map, icp, cps, and ebp. Check for 5v after unplugging each. Still no 5v check for power and grounds at the pcm.
It should be 5v.
If it is not unplug accelerator pedal sensor, map, icp, cps, and ebp. Check for 5v after unplugging each. Still no 5v check for power and grounds at the pcm.
Thread Starter
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Tuned
Joined: May 2021
Posts: 363
Likes: 121
From: Montana
Check voltage, key on, on the brown/white wire on the exhaust back pressure sensor, or the map, or icp whichever is easier for you.
It should be 5v.
If it is not unplug accelerator pedal sensor, map, icp, cps, and ebp. Check for 5v after unplugging each. Still no 5v check for power and grounds at the pcm.
It should be 5v.
If it is not unplug accelerator pedal sensor, map, icp, cps, and ebp. Check for 5v after unplugging each. Still no 5v check for power and grounds at the pcm.
Flying a little blind here. Would this indicate a short in ICP wiring that is shorting PCM?
Lead Driver
Joined: Jul 2017
Posts: 6,846
Likes: 2,326
From: WV
Originally Posted by S-squatch
Check voltage, key on, on the brown/white wire on the exhaust back pressure sensor, or the map, or icp whichever is easier for you.
It should be 5v.
If it is not unplug accelerator pedal sensor, map, icp, cps, and ebp. Check for 5v after unplugging each. Still no 5v check for power and grounds at the pcm.
It should be 5v.
If it is not unplug accelerator pedal sensor, map, icp, cps, and ebp. Check for 5v after unplugging each. Still no 5v check for power and grounds at the pcm.
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,344
Likes: 5,941
From: Lake Hartwell, GA
^^^ What Jason said...
Also, this will be a post I link and refer to in the future as we rarely see that as a suggested fix action.
Also, this will be a post I link and refer to in the future as we rarely see that as a suggested fix action.
Thread Starter
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Tuned
Joined: May 2021
Posts: 363
Likes: 121
From: Montana
Quick update: ended up it was my EBP sensor, not the IPR. I misidentified it last night. Picked up a new EBP sensor at the dealer this morning and was back at the job site only a couple hours late after putting it in. Not a bad turn around time for a malfunction like this. Truck ran great today...
Many thanks to all who helped out with suggestions. Props to Squatch for bringing up sensor failures as a route for losing the PCM!
Many thanks to all who helped out with suggestions. Props to Squatch for bringing up sensor failures as a route for losing the PCM!
