GPR and PCM
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you can't fix stupid!
Joined: Mar 2008
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GPR and PCM
alright i have absolutely no problems starting my girl in the cold. however my buddy ha an 02 F350 powerstroke bone stock and is having some problems. he was telling me about all kinds of problems he had with the gpr before the warranty went out with ford on his truck and he is back to having them again. apparently hos gpr went bad so i kept telling him about the stancor unit but he ended up buying a different one. this gpr if it even is one is supposedly bad as well out of the package. not unheard of but i am wondering if he even got the right thing. i told him to order the stancor unit and he should be fine. he doesnt want to spend the money on another gpr until he is convinced his pcm is working right and sending the right signals to the gpr for proper operation. i did have him jump the terminals on the new gpr and it started up like normal. thats why i think the gpr he got was a doa. what can i have him check or do to show that the pcm is working correctly with the gpr. or does the pcm even have that much to do with the gpr? i keep trying to get him to change to synthetic oil also but im not having much luck convincing him about all the cool stuff he can do to the rig to make it better. any ideas?
Posting Guru
Joined: Feb 2009
Posts: 1,325
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From: Blaine, TN
You can check the signal wire on the GPR that comes from the pcm with a multimeter or a test light to see if it is even getting the signal for the relay to turn on, if it is not, check all the wiring for cuts, burns, loose connections etc all the way back, if it is not getting a signal and the wires look good, see if you can find someone nearby with AE to take a look at the pcm signals and inputs for the GP's and relay, as well as the oil temp sensor input and voltage.
Post Fiend
Joined: Nov 2007
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From: Payson, AZ
The quick and dirty way to test the GPR for operation is to either listen or feel for it to operate. If it is operating then check that it is passing the battery from terminal 2 (always hot) to terminal 4.
If it is not operating perform the following:
To test the GPR lift the wires on terminals 3 & 5 (the small wires). Apply battery to terminal 3 and then ground terminal 5. You should hear and/or feel the GPR operate. While operated you should be able to measure battery at terminal 4. Terminal 2 should always be hot.
Test PCM control with terminal 3 and 5 lifted. Turn key to on position. The wire lifted from terminal 3 should have battery and the wire lifted from terminal 5 should have a ground. Test while vehicle is cold and remember, depending on the temp, the control leads will only be active for a max of about 120 seconds.
If it is not operating perform the following:
To test the GPR lift the wires on terminals 3 & 5 (the small wires). Apply battery to terminal 3 and then ground terminal 5. You should hear and/or feel the GPR operate. While operated you should be able to measure battery at terminal 4. Terminal 2 should always be hot.
Test PCM control with terminal 3 and 5 lifted. Turn key to on position. The wire lifted from terminal 3 should have battery and the wire lifted from terminal 5 should have a ground. Test while vehicle is cold and remember, depending on the temp, the control leads will only be active for a max of about 120 seconds.
New User
Joined: Mar 2007
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This is a sore subject for me, because I purchased a replacement GPR from Orieleys and appaently it was a starter relay in a GPR box. One of the small terminals was a different size and copper color. But like an idiot I installed it anyway even having to finf a nut to fit the copper small terminal. Started it up and it wouldn't shut back off!. I thought maybe I had the small terminals reversed (I'm an electrician by trade so this brain fart hurts even worse). So I swapped the small wires and it would shut off but apparently I fried the contacts in my PCM that send the ground. I've ohmed out the wire to the firewall plug. So now I have a push button for my GPR. It gets worse. I purchased a remanufactured PCM from the big name place out of Florida for around $300. installed it without my DP tuner in and it ran like ****, the OD light was flashing and it had no power. So instead of returning it with the seal intact like an idiot again I got the bright idea. Maybe it would work better with the DP chip installed. Well it didn't and breaking the seal to install the chip means no replacement from the place that sold it to me. So I had to send it back as my core and it was a $300 experiment. My *** is still sore from all this reaming! Of course my stupidity was mostly the problem.
Can I get a hug? ha ha
Can I get a hug? ha ha
Thread Starter
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you can't fix stupid!
Joined: Mar 2008
Posts: 1,906
Likes: 2
The quick and dirty way to test the GPR for operation is to either listen or feel for it to operate. If it is operating then check that it is passing the battery from terminal 2 (always hot) to terminal 4.
If it is not operating perform the following:
To test the GPR lift the wires on terminals 3 & 5 (the small wires). Apply battery to terminal 3 and then ground terminal 5. You should hear and/or feel the GPR operate. While operated you should be able to measure battery at terminal 4. Terminal 2 should always be hot.
Test PCM control with terminal 3 and 5 lifted. Turn key to on position. The wire lifted from terminal 3 should have battery and the wire lifted from terminal 5 should have a ground. Test while vehicle is cold and remember, depending on the temp, the control leads will only be active for a max of about 120 seconds.
If it is not operating perform the following:
To test the GPR lift the wires on terminals 3 & 5 (the small wires). Apply battery to terminal 3 and then ground terminal 5. You should hear and/or feel the GPR operate. While operated you should be able to measure battery at terminal 4. Terminal 2 should always be hot.
Test PCM control with terminal 3 and 5 lifted. Turn key to on position. The wire lifted from terminal 3 should have battery and the wire lifted from terminal 5 should have a ground. Test while vehicle is cold and remember, depending on the temp, the control leads will only be active for a max of about 120 seconds.
how much battery should be at terminal 3? 12 volts or like a half a volt?
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Post Fiend
Joined: Nov 2007
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From: Payson, AZ
I can't remember exactly what I measured but I'm quite sure it was 11+ volts.
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Postmaster
Joined: Dec 2008
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re
That is true unless the pcm is not sending the ground signal to the gpr . Looks like #3 in Robin's post. Lisa, what are you doing at home on a happening Friday night?
Smokin
Joined: Jun 2006
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Happening Friday night? I live in Cedar Rapids Iowa and all of my friends and family are 600 miles away...if that answers your question.
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