Glow Plug Contol Module (GPCM)
Posting Guru
Joined: Dec 2004
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From: Virginia - SW (Riner)
GP Module
Unless yours is a CA truck it won't have one. No idea how many of these are running around - in our neck of the woods they are extremely rare. I think I've seen maybe 2 in the last 3-4 years.
If my memory serves me correctly the module is under the kick panel on the pass side. I may be getting this confused w/ the PCM though.
Both of the ones I worked on were 'transplants' that had come in w/ people moving in from CA looking to get a VA state annual inspection.
I think this may be a NE requirement too - MA?
DG
If my memory serves me correctly the module is under the kick panel on the pass side. I may be getting this confused w/ the PCM though.
Both of the ones I worked on were 'transplants' that had come in w/ people moving in from CA looking to get a VA state annual inspection.
I think this may be a NE requirement too - MA?
DG
Tuned
Joined: Jun 2003
Posts: 465
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From: Connecticut
Originally Posted by dagren99
Unless yours is a CA truck it won't have one...they are extremely rare.
...module is under the kick panel on the pass side.
Are you having a specific problem with yours? Code 0683 or similar?
Post Fiend
Joined: Mar 2007
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From: Texas
Welcome to FTE. As pointed out above. The GPCM is only installed on CA trucks (& other states following CA emissions) and all Excursions. There's a very nice picture of it above. (Thanks Greg)
What kind of problems are you having?
What kind of problems are you having?
Posting Guru
Joined: Dec 2004
Posts: 1,102
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From: Virginia - SW (Riner)
Quote
Quoted by Greg A - Originally Posted by dagren99
Unless yours is a CA truck it won't have one...they are extremely rare
Need to read the whole thing - I said RARE in our neck of the woods not, rare everywhere.
We do not work on many Excursions (we are mainly a med/heavy duty truck shop) and the few we have worked on have had either the 6.0 or the V10. Can't recall us working on a Ex w/ a 7.3 in quite a while. Not a ton of them around here anyway - lots & lots of F250, F350 & up trucks.
DG
Unless yours is a CA truck it won't have one...they are extremely rare
Need to read the whole thing - I said RARE in our neck of the woods not, rare everywhere.
We do not work on many Excursions (we are mainly a med/heavy duty truck shop) and the few we have worked on have had either the 6.0 or the V10. Can't recall us working on a Ex w/ a 7.3 in quite a while. Not a ton of them around here anyway - lots & lots of F250, F350 & up trucks.
DG
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Mine does not have one...My problem is the the Glow plugs were not activating. The "Wait to Start" light would not come on and the engine spins over will not fire. I think the problem is somewhere else. Pherhap the PCM. Because at 60 f. the Glow Plugs should not be needed to start. I swapped the relay with the blowere motor relay and haven't had any problems for the past 3 days. I am praying the relay may have been sticking.....Any thoughts
Post Fiend
Joined: Mar 2007
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From: Texas
Sounds like you've got a shorted fuel bowl heater. When that goes it blows a fuse (#30 on several trucks). The fuse also powers the PCM so the injectors aren't told to fire.
What year is your truck? Start by checking the fuses really well. Sometimes they won't look blown. See if your manual says something about the fuel bowl heater/pcm on fuse #30 or any other location. After you replace the fuse, unplug the fuel bowl heater (electrical plug on the back side of the fuel bowl) and try to start it then. If you leave it plugged in the fuse will blow again.
You can live without the fuel bowl heater so don't worry about driving with it unplugged. If this fixes the problem we can tell you how to change the heater if you want to.
What year is your truck? Start by checking the fuses really well. Sometimes they won't look blown. See if your manual says something about the fuel bowl heater/pcm on fuse #30 or any other location. After you replace the fuse, unplug the fuel bowl heater (electrical plug on the back side of the fuel bowl) and try to start it then. If you leave it plugged in the fuse will blow again.
You can live without the fuel bowl heater so don't worry about driving with it unplugged. If this fixes the problem we can tell you how to change the heater if you want to.
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I did not replace a fuse it and it has not acted up in 3 days so what do you think. When you refer to the fuel bowl are you talking about where the fuel filter goes???
Thanks for you help?????????????
Thanks for you help?????????????
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Post Fiend
Joined: Mar 2007
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From: Texas
Sorry, I skimmed over the part that said you've had it running for 3 days with no problems. The fuel bowl is where the filter goes. If you're problem has gone away completely then the relay may be all you need. Does your blower work fine with the questionable relay?
Also FYI. The wait to start light is not actually connected to the glow plugs. The glow plugs will work without the light and vice versa. You can use a multi-meter to check the glow plug relay immediately after the key is turned on to see if it is sending power to the glow plugs, but as you mentioned at 60 deg. I don't think that would keep it from starting. Maybe just take a little longer to start.
Also FYI. The wait to start light is not actually connected to the glow plugs. The glow plugs will work without the light and vice versa. You can use a multi-meter to check the glow plug relay immediately after the key is turned on to see if it is sending power to the glow plugs, but as you mentioned at 60 deg. I don't think that would keep it from starting. Maybe just take a little longer to start.
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Thanks! You do not know how much I appreciate the help...
Let me recount what happened and see if you have any more ideas.
Sunday morning turned key on no "WTS" light. I thought perhaps i did not turn key on fully. switched off back on still nothing I waited a 30 sec. tried to start it just spins over (31 degrees) I switch off and on a few times then it came on for a split second. switched on/off few more times and I got the light stay on as it usually did if fired up. when down the road about 1/4 mile to the stop light It died but started right back up. No more problems that day or next Morning but at lunch it did this again at 60 degrees. I relaced the Glow Plug seleniod still acted up. I switched the relays around and it has not did this again since that time. And the blower motor has operated fine too...
Anything else you think I should check?
Thanks again,
Steve
Let me recount what happened and see if you have any more ideas.
Sunday morning turned key on no "WTS" light. I thought perhaps i did not turn key on fully. switched off back on still nothing I waited a 30 sec. tried to start it just spins over (31 degrees) I switch off and on a few times then it came on for a split second. switched on/off few more times and I got the light stay on as it usually did if fired up. when down the road about 1/4 mile to the stop light It died but started right back up. No more problems that day or next Morning but at lunch it did this again at 60 degrees. I relaced the Glow Plug seleniod still acted up. I switched the relays around and it has not did this again since that time. And the blower motor has operated fine too...
Anything else you think I should check?
Thanks again,
Steve
Post Fiend
Joined: Mar 2007
Posts: 26,966
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From: Texas
The CPS is always a possibility when it comes to stalling or no starts. Did you get any other dash lights not acting normally during the no start or stall?
Something that may or may not be related, but I would recommend checking anyway is the main engine wiring harness. It's the big wiring harness that comes up and over the drivers side valve cover. They've been known to rub against the valve cover or bracket above the valve cover and chaff some wires. If the right wire is chaffed it can cause a stall or no start. Since you can check this for free and without much difficulty it's worth the time.
Something that may or may not be related, but I would recommend checking anyway is the main engine wiring harness. It's the big wiring harness that comes up and over the drivers side valve cover. They've been known to rub against the valve cover or bracket above the valve cover and chaff some wires. If the right wire is chaffed it can cause a stall or no start. Since you can check this for free and without much difficulty it's worth the time.
Post Fiend
Joined: Nov 2007
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From: Payson, AZ
Just by swapping the relays you may have ensured better contact between one or more of the male spade connectors with its corresponding female connector. If you swap the relays back to their original positions and the trouble returns you will know you have a bad relay. I personally would leave them where they are and if the blower motor quits you will know the first thing to suspect.
