How to test GPCM

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Apr 5, 2008 | 03:52 PM

ferret2

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Joined: Mar 2005

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From: House Springs, MO

How to test GPCM

Just got a 2000 X PSD with 145xxx miles. I'm selling my 2000 F250 PSD since I needed more seating for the family. Comparing the two I don't think I'm getting any glow plugs (longer crank). Unlike the GPR which I know how to test how can I check the GPCM? I haven't checked codes but I have no SES light. I know I can check the GP individually by removing the connector at the valve cover and check resistance but I really don't suspect that.

Any thoughts?

Thanks
Craig

Apr 5, 2008 | 03:56 PM

superduty4x4

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From: Newport, WA

If you don't have an SES light then the GPCM is probably fine- glow plug problems throw the light on the Cali fuel trucks. Your batts might be weak.

Apr 5, 2008 | 08:45 PM

F350-6

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From: Texas

Chase is right. The GPCM is designed to throw a SES light if there are any problems with the glow plug system. It will even tell you which glow plug is the problem.

If the batteries are good, what about fluids & filters?

Apr 5, 2008 | 09:50 PM

superduty4x4

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From: Newport, WA

Quote:

Originally Posted by F350-6

When I had the codes pulled on my truck, all it said was "Faulty glow plug on bank 2"- the tech still had to do a pin test to see which one it was. Code was P1693.

Apr 5, 2008 | 10:02 PM

F350-6

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From: Texas

Do you have a CA truck Chase?

Usually the GPCM will set these codes.
P0670 Glow plug control circuit malfunction
P0671 Glow plug #1 circuit failure
P0672 Glow plug #2 circuit failure
P0673 Glow plug #3 circuit failure
P0674 Glow plug #4 circuit failure
P0675 Glow plug #5 circuit failure
P0676 Glow plug #6 circuit failure
P0677 Glow plug #7 circuit failure
P0678 Glow plug #8 circuit failure
P0683 Glow plug diagnostic signal communication fault

Apr 6, 2008 | 10:38 AM

superduty4x4

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From: Newport, WA

Yep mine's a Cali. I don't know what program/software the tech used to pull my code, but here's what my invoice says: "CHECK ENGINE LIGHT ON. IDS EVALUATION KOEO PCM=P1693 DIAGNOSIS FAULTY GLOW PLUG ON BANK 2" I did see the same thing on the screen of the tech's laptop.
What is code P1693?

Apr 6, 2008 | 11:43 AM

F350-6

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From: Texas

1693 doesn't show up in the basic list of P codes in my manual (but that's for the 02). Are you sure you got the number right? I'll dig around and see if I can find the 1693 somewhere else. They sometimes have them hidden in the pinpoint tests.

If you look up P1693 on Guzzles site it doesn't have anything to do with the glow plugs. If you haven't seen the page it's a good one to bookmark.

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