Code P1633, electrical problems
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Junior User
Joined: Oct 2013
Posts: 50
Likes: 0
From: Anthem, AZ
Code P1633, electrical problems
I have another thread about this problem, but wanted to start one that is more specific and detailed to just this problem.
2000 F250 4x4 V10
I’m getting code P1633, no power to Keep Alive Memory
Here are the syptoms…
First, the voltmeter shows under 10 volts.
When this happens, the check engine light comes on and throws code P1633.
Also, I can’t shift out of park for some reason when the voltmeter shows under 10 volts.
Also, when I apply the brake, the voltmeter drops completely, no other functions seem to affect it other than applying the brake. I know this is related to the shift interlock which could have something to do with not sensing the brake is applied and won’t come out of park.
What I’ve checked so far…
Battery has good voltage
Alternator is charging
Fuse to PCM shows good voltage
Fuses to voltmeter and shift interlock show good voltage
All grounds I’ve found are good
The one problem I have found is there is no power to pin 55 to PCM, Keep alive power circuit.
So, I’m trying to figure out where the voltmeter gets it’s signal from after the fuse box under the dash or where it is grounded, I found the shift interlock ground and it is good.
Would the fact that there is no power to pin 55 cause the voltmeter problem and shift interlock problem? I’m tempted to jump power to that pin, but this will not be easy and I don’t want to do it if it will just mask the real problem.
Also, when I was first experiencing this problem, the voltmeter would jump around when going over bumps while driving, then it would finally settle under 10 volts. At one time I couldn’t drive the truck and kept turning it off then on in hopes it would go back to normal, I applied the parking brake then released it and let it slam up, after that it went back to normal, not sure if the jolt helped make a connection or what, but I would lean towards a loose connection because of the jumping around of the gauge. Now it’s constant though, I messed with a ton of wiring and can’t get it to go back to normal. Is there another module that has to do with any of these functions or anything that ties them all together that I am missing?
I hope someone has some insight on this as I’m at a loss. I’m hoping there are no driveability issues with this problem, I’ll be going on a camping trip in a couple weeks and doubt I’ll have it fixed by then. I figured out how to get it out of park bypassing the shift interlock, so that’s not a problem. Any other advice or concerns I should consider?
Thanks
2000 F250 4x4 V10
I’m getting code P1633, no power to Keep Alive Memory
Here are the syptoms…
First, the voltmeter shows under 10 volts.
When this happens, the check engine light comes on and throws code P1633.
Also, I can’t shift out of park for some reason when the voltmeter shows under 10 volts.
Also, when I apply the brake, the voltmeter drops completely, no other functions seem to affect it other than applying the brake. I know this is related to the shift interlock which could have something to do with not sensing the brake is applied and won’t come out of park.
What I’ve checked so far…
Battery has good voltage
Alternator is charging
Fuse to PCM shows good voltage
Fuses to voltmeter and shift interlock show good voltage
All grounds I’ve found are good
The one problem I have found is there is no power to pin 55 to PCM, Keep alive power circuit.
So, I’m trying to figure out where the voltmeter gets it’s signal from after the fuse box under the dash or where it is grounded, I found the shift interlock ground and it is good.
Would the fact that there is no power to pin 55 cause the voltmeter problem and shift interlock problem? I’m tempted to jump power to that pin, but this will not be easy and I don’t want to do it if it will just mask the real problem.
Also, when I was first experiencing this problem, the voltmeter would jump around when going over bumps while driving, then it would finally settle under 10 volts. At one time I couldn’t drive the truck and kept turning it off then on in hopes it would go back to normal, I applied the parking brake then released it and let it slam up, after that it went back to normal, not sure if the jolt helped make a connection or what, but I would lean towards a loose connection because of the jumping around of the gauge. Now it’s constant though, I messed with a ton of wiring and can’t get it to go back to normal. Is there another module that has to do with any of these functions or anything that ties them all together that I am missing?
I hope someone has some insight on this as I’m at a loss. I’m hoping there are no driveability issues with this problem, I’ll be going on a camping trip in a couple weeks and doubt I’ll have it fixed by then. I figured out how to get it out of park bypassing the shift interlock, so that’s not a problem. Any other advice or concerns I should consider?
Thanks
Cargo Master
Joined: Feb 2011
Posts: 3,450
Likes: 13
From: Forest lake minnesota
I have another thread about this problem, but wanted to start one that is more specific and detailed to just this problem.
2000 F250 4x4 V10
I’m getting code P1633, no power to Keep Alive Memory
Here are the syptoms…
First, the voltmeter shows under 10 volts.
When this happens, the check engine light comes on and throws code P1633.
Also, I can’t shift out of park for some reason when the voltmeter shows under 10 volts.
Also, when I apply the brake, the voltmeter drops completely, no other functions seem to affect it other than applying the brake. I know this is related to the shift interlock which could have something to do with not sensing the brake is applied and won’t come out of park.
What I’ve checked so far…
Battery has good voltage
Alternator is charging
Fuse to PCM shows good voltage
Fuses to voltmeter and shift interlock show good voltage
All grounds I’ve found are good
The one problem I have found is there is no power to pin 55 to PCM, Keep alive power circuit.
So, I’m trying to figure out where the voltmeter gets it’s signal from after the fuse box under the dash or where it is grounded, I found the shift interlock ground and it is good.
Would the fact that there is no power to pin 55 cause the voltmeter problem and shift interlock problem? I’m tempted to jump power to that pin, but this will not be easy and I don’t want to do it if it will just mask the real problem.
Also, when I was first experiencing this problem, the voltmeter would jump around when going over bumps while driving, then it would finally settle under 10 volts. At one time I couldn’t drive the truck and kept turning it off then on in hopes it would go back to normal, I applied the parking brake then released it and let it slam up, after that it went back to normal, not sure if the jolt helped make a connection or what, but I would lean towards a loose connection because of the jumping around of the gauge. Now it’s constant though, I messed with a ton of wiring and can’t get it to go back to normal. Is there another module that has to do with any of these functions or anything that ties them all together that I am missing?
I hope someone has some insight on this as I’m at a loss. I’m hoping there are no driveability issues with this problem, I’ll be going on a camping trip in a couple weeks and doubt I’ll have it fixed by then. I figured out how to get it out of park bypassing the shift interlock, so that’s not a problem. Any other advice or concerns I should consider?
Thanks
2000 F250 4x4 V10
I’m getting code P1633, no power to Keep Alive Memory
Here are the syptoms…
First, the voltmeter shows under 10 volts.
When this happens, the check engine light comes on and throws code P1633.
Also, I can’t shift out of park for some reason when the voltmeter shows under 10 volts.
Also, when I apply the brake, the voltmeter drops completely, no other functions seem to affect it other than applying the brake. I know this is related to the shift interlock which could have something to do with not sensing the brake is applied and won’t come out of park.
What I’ve checked so far…
Battery has good voltage
Alternator is charging
Fuse to PCM shows good voltage
Fuses to voltmeter and shift interlock show good voltage
All grounds I’ve found are good
The one problem I have found is there is no power to pin 55 to PCM, Keep alive power circuit.
So, I’m trying to figure out where the voltmeter gets it’s signal from after the fuse box under the dash or where it is grounded, I found the shift interlock ground and it is good.
Would the fact that there is no power to pin 55 cause the voltmeter problem and shift interlock problem? I’m tempted to jump power to that pin, but this will not be easy and I don’t want to do it if it will just mask the real problem.
Also, when I was first experiencing this problem, the voltmeter would jump around when going over bumps while driving, then it would finally settle under 10 volts. At one time I couldn’t drive the truck and kept turning it off then on in hopes it would go back to normal, I applied the parking brake then released it and let it slam up, after that it went back to normal, not sure if the jolt helped make a connection or what, but I would lean towards a loose connection because of the jumping around of the gauge. Now it’s constant though, I messed with a ton of wiring and can’t get it to go back to normal. Is there another module that has to do with any of these functions or anything that ties them all together that I am missing?
I hope someone has some insight on this as I’m at a loss. I’m hoping there are no driveability issues with this problem, I’ll be going on a camping trip in a couple weeks and doubt I’ll have it fixed by then. I figured out how to get it out of park bypassing the shift interlock, so that’s not a problem. Any other advice or concerns I should consider?
Thanks
Thread Starter
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Junior User
Joined: Oct 2013
Posts: 50
Likes: 0
From: Anthem, AZ
There is no evidence of any water ever getting in, I know it is not leaking now, it has rained hard since I've had the truck and I checked it out after and no water got in.
I'm focusing on the brake/shift interlock/pcm relation, it looks like there is a GEM module that ties these together. I'm trying to post the diagram, but there is no web link to it, not sure how to just post a jpeg? It looks like the brake pedal switch, pcm and instrument cluster all go to fuse # 15 in the dash fuse box and that fuse has a GEM module off of it.
Maybe I'll have to call the dealer tomorrow and see what that module is for. What do these modules even look like and where are they? Is it attached to the fuse box, does it just plug in?
I'm focusing on the brake/shift interlock/pcm relation, it looks like there is a GEM module that ties these together. I'm trying to post the diagram, but there is no web link to it, not sure how to just post a jpeg? It looks like the brake pedal switch, pcm and instrument cluster all go to fuse # 15 in the dash fuse box and that fuse has a GEM module off of it.
Maybe I'll have to call the dealer tomorrow and see what that module is for. What do these modules even look like and where are they? Is it attached to the fuse box, does it just plug in?
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,081
From: St Louis
The GEM module is a multi-function module that controls or interfaces all the ancillary sub-systems in the truck that do not have an otherwise specialized module as a controller.
If you have found that there is not power at PCM pin 55, you need to focus on the circuit back through fuse F15 (and its supply, if necessary) since that "no voltage" condition is the specific cause of your P1633 DTC.
If you have found that there is not power at PCM pin 55, you need to focus on the circuit back through fuse F15 (and its supply, if necessary) since that "no voltage" condition is the specific cause of your P1633 DTC.
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,081
From: St Louis
The GEM module is a multi-function module that controls or interfaces all the ancillary sub-systems in the truck that do not have an otherwise specialized module as a controller.
If you have found that there is not power at PCM pin 55, you need to focus on the circuit back through fuse F15 (and its supply, if necessary) since that "no voltage" condition is the specific cause of your P1633 DTC as well as the problem with the shift interlock.
CJB F15 supplies "keep alive" power to the PCM, GEM, and the instrument cluster as well as providing power for the position signalling half of the brake switch. With power lost to the BPP, the shift interlock cannot work, the speed control won't disengage properly, if 4X4, you won't be able to shift into low range, and the ABS system and the PCM won't know the brake pedal pedal has been pushed so ABS won't work and the PCM won't be able to properly compensate for braking action in its management of the the engine and transmission systems.
If you have found that there is not power at PCM pin 55, you need to focus on the circuit back through fuse F15 (and its supply, if necessary) since that "no voltage" condition is the specific cause of your P1633 DTC as well as the problem with the shift interlock.
CJB F15 supplies "keep alive" power to the PCM, GEM, and the instrument cluster as well as providing power for the position signalling half of the brake switch. With power lost to the BPP, the shift interlock cannot work, the speed control won't disengage properly, if 4X4, you won't be able to shift into low range, and the ABS system and the PCM won't know the brake pedal pedal has been pushed so ABS won't work and the PCM won't be able to properly compensate for braking action in its management of the the engine and transmission systems.
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Thread Starter
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Junior User
Joined: Oct 2013
Posts: 50
Likes: 0
From: Anthem, AZ
I have good voltage at fuse 15. Is there a way to remove the fuse box under the dash? I had it unbolted and tried to get it out, but it didn't seem like there was room, is there a trick? Could the GEM be the problem? It would make sense as it seems the problem could be in that area if messing with the parking brake had anything to do with it before. I want to pull the fuse box and get a better look at the wiring going into it and the GEM, just don't know how to get it out...
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Thread Starter
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Junior User
Joined: Oct 2013
Posts: 50
Likes: 0
From: Anthem, AZ
I had a few minutes to work on this tonight and think I found the problem. I grapped one of the plugs for the fuse box and pushed on the wires right at the plug and got my voltmeter to go to normal, then drop off, then back as I move the bunch of wires. So out came the fuse box so I could check the terminals and plug. All looked fine at first glance, but obviously something was wrong.
I took a closer look at each terminal on the plug and noticed one of them was pushed further back than the others. Turns out is was the light blue/black that goes from the fuse box to the brake pedal switch, instrment cluster and pin 55 for the PCM! This has to be it!!
Now the only problem is getting the terminal to stay in the plug, the detent will not hold anymore no matter what I try. Any suggestions on how to get it to stay? I think the only option is to try and glue it somehow, maybe just get some silicone in on the wire side to the back side of the terminal and hope that adheres to the plastic housing? Maybe I'll try that and check it tomorrow night...
Thanks for all the help so far, this was my last problem I was stumped on with this truck, I'm pretty confident this will solve it and be good to go for next weekend!
I took a closer look at each terminal on the plug and noticed one of them was pushed further back than the others. Turns out is was the light blue/black that goes from the fuse box to the brake pedal switch, instrment cluster and pin 55 for the PCM! This has to be it!!
Now the only problem is getting the terminal to stay in the plug, the detent will not hold anymore no matter what I try. Any suggestions on how to get it to stay? I think the only option is to try and glue it somehow, maybe just get some silicone in on the wire side to the back side of the terminal and hope that adheres to the plastic housing? Maybe I'll try that and check it tomorrow night...
Thanks for all the help so far, this was my last problem I was stumped on with this truck, I'm pretty confident this will solve it and be good to go for next weekend!
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,081
From: St Louis
Good, you've found the issue.
I've made similar field repairs on industrial equipment using a combination of a wooden toothpick/matchstick, a sharp whittlin' knife, and a bit of epoxy to hold it together. Be careful that the adhesive doesn't make it to the electrical contact area as that will insulate the desired connection.
I've made similar field repairs on industrial equipment using a combination of a wooden toothpick/matchstick, a sharp whittlin' knife, and a bit of epoxy to hold it together. Be careful that the adhesive doesn't make it to the electrical contact area as that will insulate the desired connection.
Thread Starter
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Junior User
Joined: Oct 2013
Posts: 50
Likes: 0
From: Anthem, AZ
Good, you've found the issue.
I've made similar field repairs on industrial equipment using a combination of a wooden toothpick/matchstick, a sharp whittlin' knife, and a bit of epoxy to hold it together. Be careful that the adhesive doesn't make it to the electrical contact area as that will insulate the desired connection.
I've made similar field repairs on industrial equipment using a combination of a wooden toothpick/matchstick, a sharp whittlin' knife, and a bit of epoxy to hold it together. Be careful that the adhesive doesn't make it to the electrical contact area as that will insulate the desired connection.
I was trying to stay away from epoxy so I wouldn't mess up the connection. The silicone didn't even dry after 24 hours, so that didn't work. I tried regular epoxy and that just won't adhere to the plastic well enough, so I'm on to some other epoxy that works well with most plastics. I thought about toothpicks to shove in and press the terminal against the housing to tighten it up a bit, but then saw a zip tie on the ground and it looked like the perfect size, so I dry tested it and it almost worked dry, so a little epoxy on the zip tie and I'll check it tomorrow and hope this try works. If not, my last resort is just cutting the wire and running it to the front of the fuse box, either way, I'm confident this will be fixed tomorrow!
New User
Joined: Aug 2017
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The GEM module is a multi-function module that controls or interfaces all the ancillary sub-systems in the truck that do not have an otherwise specialized module as a controller.
If you have found that there is not power at PCM pin 55, you need to focus on the circuit back through fuse F15 (and its supply, if necessary) since that "no voltage" condition is the specific cause of your P1633 DTC as well as the problem with the shift interlock.
CJB F15 supplies "keep alive" power to the PCM, GEM, and the instrument cluster as well as providing power for the position signalling half of the brake switch. With power lost to the BPP, the shift interlock cannot work, the speed control won't disengage properly, if 4X4, you won't be able to shift into low range, and the ABS system and the PCM won't know the brake pedal pedal has been pushed so ABS won't work and the PCM won't be able to properly compensate for braking action in its management of the the engine and transmission systems.
If you have found that there is not power at PCM pin 55, you need to focus on the circuit back through fuse F15 (and its supply, if necessary) since that "no voltage" condition is the specific cause of your P1633 DTC as well as the problem with the shift interlock.
CJB F15 supplies "keep alive" power to the PCM, GEM, and the instrument cluster as well as providing power for the position signalling half of the brake switch. With power lost to the BPP, the shift interlock cannot work, the speed control won't disengage properly, if 4X4, you won't be able to shift into low range, and the ABS system and the PCM won't know the brake pedal pedal has been pushed so ABS won't work and the PCM won't be able to properly compensate for braking action in its management of the the engine and transmission systems.
I have a 2010 F550 diesel and don't have F15. Batteries are new, PCM is new, all fuses are good. Any suggestions?
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,081
From: St Louis
Any suggestions?
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