PCM Replacement?

2002 FORD F-250
240,000 MILES • 7.3L • V8 • TURBO • 4WD • AUTOMATIC
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I bought this from a dealer for a great price a years ago. Current issues I can name are. Key fob and inside toggles for lock and unlocks haven’t worked. The windshield wipers would randomly stop working. 90% sure it’s fuse 302/power train EEC relay is ticking constantly but stops when brakes are applied. The taillights stay on with no power to them but the brake lights don’t work. The turn signals don’t work. When driving down the road, the headlights went out. The running lights still and when toggled to park lights I have running lights but the main headlights don’t work when toggled. The door open light is always on but I’ve used a snap on computer with the OBD and the computer says they’re closed when I have all for open. Had a code to replace ECU and I did that today. Nothing has changed and I’m stuck. All fuses were checked. There was another relay in the engine compartment ticking but couldn’t find out what it was. Swapping relays fixed the one in the engine compartment from what I see. I can provide pictures or details for anything else, I’m just lost. Could it be a bad PCM?
Apr 8, 2020 at 6:33 PM
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JACOBANDNICKOLAS
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Wow, I'm not sure where to start with this one. Have you checked all grounds? I ask because there are so many unrelated issues. It doesn't seem like a power issue. You mentioned the ECU. Are you referring to the body control module?

Let me know.
Joe
Apr 8, 2020 at 7:53 PM
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I have but I would need a document to make sure I’ve covered all grounds. Yes, sorry ECM .
Apr 9, 2020 at 3:16 AM
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JACOBANDNICKOLAS
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Hi,

Here are the schematics for all grounds on the vehicle. Take a look through them and let me know if it helps or if you have questions. Note that I had to cut each page in two so you can read them. I did overlap them to make it easy to follow.

________________________________________

Let me know if this helps.

Joe

Apr 9, 2020 at 7:52 AM
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Thank you. Just for reference, I was able to get codes using a snap on scanner.

memory codes from PCM:
P0381, glow plug indicator
P0603, internal control module KAM error

Switch test codes:
P1536, parking brake switch circuit fault
P1780, TCS our of self test range
P0571, cruise brake switch circuit fault
P0703, brake switch input fault
P0565, cruise on signal fault
P0566, cruise off signal fault
P0567, cruise remain signal fault
P0568, cruise set signal fault
P0569, cruise coast signal fault

memory codes from GEM:
P1820, T-case CW shift relay circuit fault
B1483, brake pedal input circuit fault
P1876, T-case 2wd solenoid circuit fault
P1832, T-case differential lockup solenoid circuit fault
B1359, ignition run/ACCY circuit duly
P1808, 4wd low indicator circuit fault
P1828, T-case CCW shift relay circuit fault

Codes from hybrid electronic cluster AND PATS anti theft, these appear to be active and memory:
B1342, faulty control module
C1284, oil pressure switch fault

Parking aid module, active and memory:
C1710, rear inner right sensor fault
C1709, rear inner right sensor circuit
C1707, LR center sensor circuit fault
C1706, rest inner left sensor circuit
C1704, rear outer right sensor fault
C1703, rear outer right sensor circuit
C1701, rear outer left sensor fault

Cannot get any reading from the VSM... code reader tells me no response, not equipped.
Apr 9, 2020 at 4:07 PM
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JACOBANDNICKOLAS
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Hi,

Honestly! Wow, I never saw so many at one time. I'm going to ask a friend to jump in with us and see if he has any suggestions.

Joe
Apr 9, 2020 at 5:09 PM
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ASEMASTER6371
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Good evening,

I read all the posts and I have one suggestion to start.

I would load test both batteries first and check the cables. Make sure they are clean and tight.

https://www.2carpros.com/articles/car-battery-load-test

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Low voltage is something in common to all the codes you have listed.

Joe gave you all the ground connections and locations but I do not think it is a ground.

Check the charge rate of the alternator. Make sure it is between 14 to 14.5 volts DC. Then change the scale to AC volts and see if there is any AC voltage.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Roy
Apr 9, 2020 at 5:33 PM
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If everything checks out it sounds like PCM is bad. Here is the location and how to replace it. Programming is required. Check out the diagrams (below). Please let us know what happens.
Apr 9, 2020 at 6:37 PM
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Roy, I will check but new batteries last January and new alternators (discovered it had 2 last year, one was fried) in the last 2 years. I do live in Iowa so it’s exposed to extreme cold every year.
Apr 9, 2020 at 7:27 PM
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Also Ken, I finally purchased an ECM flashed to my vehicle off of eBay. There were no changes in anything when I popped the new one in so I had it sent back. What about the VSM?
Apr 9, 2020 at 7:30 PM
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JACOBANDNICKOLAS
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Okay. Now you have two of the best helping. Thank you Ken and Roy for joining. Roy, could the low voltage issue be related to a ground / weak ground? That is what I was thinking because he replaced the ECM.

Thorn616: When you say VSM, are you referring to the Vehicle Security Module? If so, I personally don't see a correlation. Perhaps Ken or Roy can confirm that. Here is what the VCM covers:

2002 Ford Truck F 250 2WD Super Duty V8-7.3L DSL Turbo VIN F

VEHICLE SECURITY MODULE
The Vehicle Security Module (VSM) controls the following Systems:
^ perimeter alarm
^ remote keyless entry (and panic feature)
^ computer-operated locks
^ autolamp

_________________________________

Joe
Apr 9, 2020 at 8:20 PM
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ASEMASTER6371
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I see you replaced the batteries and alternator year ago. That was then and this is now.

You need to start testing as I suggested.

Roy
Apr 10, 2020 at 3:51 AM
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Will start testing. Every problem I had before replacing batteries and alternators existed after they were replaced.
Apr 10, 2020 at 6:53 AM
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ASEMASTER6371
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Okay, got it.

Does this mean this issue has been going on for the past year or so?

Roy
Apr 10, 2020 at 6:58 AM
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At least 2 years since I’ve had it, but the only “new” issues that I’ve experienced myself are: the turn signals stopped working, which sometimes the hazards flash a couple times before totally not working, the taillights and the front signal lights, below the headlights having, power with no switches turned or key on, and the headlights stop while going down the road, which now when you turn the knob the headlights do not turn on. I believe everything else was there when I bought it just kind of masked. Mechanically I have no issues....
Apr 10, 2020 at 10:04 AM
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ASEMASTER6371
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Okay, then I would also look at the body control module as well. Most of all the items in the list of problems have the BCM as a common denominator.

Do the other checks I suggested as well.

Roy
Apr 10, 2020 at 10:11 AM
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Got it. Thank you sir.
Apr 10, 2020 at 10:13 AM
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Would this also be the GEM module, Roy?
Apr 10, 2020 at 10:21 AM
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I may get one coming just to try and return if it doesn’t work. Does that need programmed to my vehicle? My apologies, were diving for into areas I haven’t toyed with yet.
Apr 10, 2020 at 10:26 AM
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ASEMASTER6371
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The GEM module is the body control module. Just a different name for the same part.

Roy
Apr 10, 2020 at 10:30 AM
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Okay Roy.. I’m struggling. I’m reading 2002 doesn’t have GEM, but a VSM. I apologize being green in this department.. if this is not the case, where’s the GEM?
Apr 10, 2020 at 4:02 PM
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ASEMASTER6371
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Okay, I finally found it. The GEM or body control module is part of the VSM. I found the part number on Alldata and it turned out to be the VSM. Go figure that one out. Thank you engineers.

Roy
Apr 10, 2020 at 4:12 PM
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Haha! so next question. Does the part number on the VSM have to match the replacement? Struggling to find one. 2c7t-15k602-aj
Apr 10, 2020 at 4:15 PM
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ASEMASTER6371
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Yes, exactly if that is the issue. It must also be programmed to your VIN number as well.

Roy
Apr 10, 2020 at 4:43 PM
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Struggling mighty to find one online. I read 4c7t-15k602-aj can replace mine?
Apr 10, 2020 at 4:46 PM
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ASEMASTER6371
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Nope, need to be exact.

I will check as well.

Roy
Apr 10, 2020 at 5:21 PM
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I may need to go check a junkyard. Sometime in the near future with everything going in right now...
Apr 10, 2020 at 5:24 PM
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ASEMASTER6371
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I understand completely.

Roy
Apr 10, 2020 at 5:29 PM
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I’ll pursue looking. Please let me know if you find anything. I can’t tell you how much I appreciate your help.
Apr 10, 2020 at 5:31 PM
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ASEMASTER6371
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I was just going to a site www.car-part.com. Good site for used parts. Enter your information and your zip code and they will list all the yards that have one, price, phone numbers and emails.

Roy
Apr 10, 2020 at 5:34 PM
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JACOBANDNICKOLAS
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Hey guys. I was reading back through this and wondered if you could check something simple for me. Under the left hand side of the dash is the central junction box (CJB). When you mentioned GEM, it brought back a memory. Check to see if there is any evidence of water leaking in on the CJB. It can cause all kinds of issues.

Joe
Apr 10, 2020 at 10:11 PM
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Fuse box doesn’t appear to have water damage.
Apr 11, 2020 at 8:51 AM
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ASEMASTER6371
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Joe is right about the fuse block.

You may not be able to see any damage as it may be internal.

Roy
Apr 11, 2020 at 9:32 AM
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I’m not sure if I mentioned it but wiggling wires in the fuse block seems to kill the truck. At least while it’s unbolted.Then have to re position to start it. Fairly confident it’s wires right in the middle and not sure if that has anything to do with the power train EEC relay clicking constantly. The click stops when the brake is pressed.
Apr 11, 2020 at 9:36 AM
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ASEMASTER6371
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While what is unbolted? The fuse block?

What about when it is running and connected? Did you wiggle the wires and see if it dies?

Roy
Apr 11, 2020 at 9:40 AM
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Yes I have it unbolted currently. Will boot it back on and wiggle wires.
Apr 11, 2020 at 9:42 AM
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ASEMASTER6371
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Keep us updated.

Roy
Apr 11, 2020 at 9:53 AM
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Okay, I couldn’t seem to get it to die while bolted up. Definitely dies when hanging while moving wires. It seemed like I couldn’t get it to die with that harness unplugged but again, rain stopped me short. It just started raining and it’s not in my garage so I came in. But, I’ve found the culprit harness of the buzzing. The red circled one. The taillights turn off when unplugged and the buzzing relay stops. When plugged in, it starts right away. There’s also a quick beep somewhere behind my dash every time it’s plugged in? I hear the same beep sometimes when starting the truck.
Apr 11, 2020 at 10:17 AM
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ASEMASTER6371
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Okay.
Apr 11, 2020 at 10:22 AM
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Any idea what that harness runs to on the other end?
Apr 11, 2020 at 10:24 AM
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ASEMASTER6371
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No, we do not have a routing diagram for the harness. You will have to follow that one.

Roy
Apr 11, 2020 at 10:31 AM