p2534 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Boog** · 03-03-2026, 05:40 PM

Anyone familiar with that dtc?
“Ignition Switch Run/Start Position Circuit Low.”

2009 Yukon 5.3
remand starter
fresh battery
charging 14 +
ignition switch was replaced over 1 year ago, probably standard ignition products brand

vehicle starts easy, though occasionally starter stays engaged after engine running. It has a new starter solenoid.
while scanning it today with my hand held, it also displayed "PO69? clutch switch". this vehicle is an automatic from factory and with no modifications.

I've read fuse boxes are known to corrode on these GMs. I'm in Arkansas so corrosion is less of a concern but still possible.

**Bob B.** · 03-04-2026, 01:45 PM

DTC 2534 indicates that the fuel pump control module is getting less than 6v from the ignition circuit when the engine is running. The fuel pump control module is located in front of the fuel tank on most of these trucks, usually behind a shield. Make sure the module is getting 12v from the ignition switch. If the wiring is fine and it is getting 12v, the module could be bad. The fuel pump control module is one of those parts that requires programming to match the vehicle, but if you need one you might be able to find a pre-programmed one on Ebay.

**Boog** · 03-04-2026, 09:17 PM

None of what I have read on p2534 mentions anything about a fuel pump control module, but I'll keep that in mind.
At O'Reillys the only module preprogrammed is a Dorman unit. Thanks

update:
I saw some green crusties in the fuse box under the run/start fuse and starter fuse. I wiped that area and sprayed electronics cleaner in there and reinserted the fuses, then started the truck 1/2 dozen times. No ses light so far. Will drive it later, see if it comes back on.

Killer Bee · 03-09-2026, 05:33 AM

if fuse terminal corrosion is the cause of failure, or an issue in general, physical terminal cleaning may be in order and a light application of dielectric grease to minimize future moisture issues that lead to corrosion.

Lisle and few others make small plastic tools with abrasive coated blades to clean female terminals.

good luck!

**Boog** · 03-11-2026, 12:29 PM

It's been about a week now and I've driven the truck several times and no dtc's have reappeared. Also the issue I had with the starter some times running on after the engine started has not happened again. I''m cautiously optimistic so far that the crusties under the starter fuse and ignition/start fuse were the culprit. Time will tell. Thanks

**Boog** · Yesterday, 09:03 AM

Update:
I did inspect the fuel pump control module connection and it was clean. Harness looked ok. I attempted to lift the fuse panel out of the box under the hood to inspect the underside but the wiring harness was so short I couldn't get it out, but what I could see looked fine.
We took a good long trip down to La to see the girls last week. 7 hours one way. The truck performed perfectly. Thanks for the help.

03-03-2026, 05:40 PM	#1
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 14,116	p2534 Anyone familiar with that dtc? “Ignition Switch Run/Start Position Circuit Low.” 2009 Yukon 5.3 remand starter fresh battery charging 14 + ignition switch was replaced over 1 year ago, probably standard ignition products brand vehicle starts easy, though occasionally starter stays engaged after engine running. It has a new starter solenoid. while scanning it today with my hand held, it also displayed "PO69? clutch switch". this vehicle is an automatic from factory and with no modifications. I've read fuse boxes are known to corrode on these GMs. I'm in Arkansas so corrosion is less of a concern but still possible. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver 'primer is finer' Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

03-04-2026, 01:45 PM	#2
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,457	Re: p2534 DTC 2534 indicates that the fuel pump control module is getting less than 6v from the ignition circuit when the engine is running. The fuel pump control module is located in front of the fuel tank on most of these trucks, usually behind a shield. Make sure the module is getting 12v from the ignition switch. If the wiring is fine and it is getting 12v, the module could be bad. The fuel pump control module is one of those parts that requires programming to match the vehicle, but if you need one you might be able to find a pre-programmed one on Ebay. __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

03-04-2026, 09:17 PM	#3
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 14,116	Re: p2534 None of what I have read on p2534 mentions anything about a fuel pump control module, but I'll keep that in mind. At O'Reillys the only module preprogrammed is a Dorman unit. Thanks update: I saw some green crusties in the fuse box under the run/start fuse and starter fuse. I wiped that area and sprayed electronics cleaner in there and reinserted the fuses, then started the truck 1/2 dozen times. No ses light so far. Will drive it later, see if it comes back on. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver 'primer is finer' Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

03-09-2026, 05:33 AM	#4
Killer Bee Registered User Join Date: Jan 2016 Location: Show-Me State Posts: 4,930	Re: p2534 if fuse terminal corrosion is the cause of failure, or an issue in general, physical terminal cleaning may be in order and a light application of dielectric grease to minimize future moisture issues that lead to corrosion. Lisle and few others make small plastic tools with abrasive coated blades to clean female terminals. good luck! __________________ *I started out with nothing - and I still have most of it*

03-11-2026, 12:29 PM	#5
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 14,116	Re: p2534 It's been about a week now and I've driven the truck several times and no dtc's have reappeared. Also the issue I had with the starter some times running on after the engine started has not happened again. I''m cautiously optimistic so far that the crusties under the starter fuse and ignition/start fuse were the culprit. Time will tell. Thanks __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver 'primer is finer' Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

Yesterday, 09:03 AM	#6
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 14,116	Re: p2534 Update: I did inspect the fuel pump control module connection and it was clean. Harness looked ok. I attempted to lift the fuse panel out of the box under the hood to inspect the underside but the wiring harness was so short I couldn't get it out, but what I could see looked fine. We took a good long trip down to La to see the girls last week. 7 hours one way. The truck performed perfectly. Thanks for the help. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver 'primer is finer' Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross



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