The Dreaded Dead Hybrid

[BoboysTruck]

The PCM Power Relay is inside the BJB on a printed circuit board.
https://www.carparts.com/blog/p068a-code-ecm-pcm-power-relay-de-energized-performance-too-early/

The 12V drops down when you connect the battery cable onto the high current battery junction box without the BJB(Fuses, Relays) plugged in, leaves the DC/DC, PSCM, BCM able to draw down the 12V.

Those are fuses. Please see the Pic I posted above for location in the hi current BJB. Below is a stock Pic of the 300A fuse.

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[BlueSpec1]

Those are fuses. Please see the Pic I posted above for location in the hi current BJB. Below is a stock Pic of the 300A fuse.

Yes that's correct the High Current Battery Junction Box contains bus bar and fuses.
The BJB plugs into it
I didn't mean to imply that relays were there, only the connections to the High Current Battery Junction Box that could cause load of the 12V battery.

The BJB Relays are integral to the BJB fuse box and not replaceable.

Probably simpler inside than this F350 BJB:
2020 Ford F-350 under hood fuse box removal, check and install

 

[BoboysTruck]

Yes that's correct the High Current Battery Junction Box contains bus bar and fuses.
The BJB plugs into it
I didn't mean to imply that relays were there, only the connections to the High Current Battery Junction Box that could cause load of the 12V battery.

The BJB Relays are integral to the BJB fuse box and not replaceable.

Probably simpler inside than this F350 BJB:
2020 Ford F-350 under hood fuse box removal, check and install

Thank you for clarifying and providing the link. I wish there was a way for me to check if these internal relays are working or not.

 

[surfstar]

I do have a 5Yr/150k miles Extended Warranty.

Am I missing something? No one on here needs to figure out how to fix this - you should be reporting back what the dealer did to fix it. Or is this not covered under your warranty?

 

[BoboysTruck]

Yes that's correct the High Current Battery Junction Box contains bus bar and fuses.
The BJB plugs into it
I didn't mean to imply that relays were there, only the connections to the High Current Battery Junction Box that could cause load of the 12V battery.

The BJB Relays are integral to the BJB fuse box and not replaceable.

Probably simpler inside than this F350 BJB:
2020 Ford F-350 under hood fuse box removal, check and install

I took my BJB apart but unlike the guy in the video, I did not see anything obvious. Worth a try anyway. It took I think four or five flat head screw drivers to pry it open.

 

[BlueSpec1]

I took my BJB apart but unlike the guy in the video, I did not see anything obvious. Worth a try anyway. It took I think four or five flat head screw drivers to pry it open.

I do wonder at the low voltage reading. If there is a huge amp draw or if the cable has a high resistance causing it to read low with any amps going thru it.

 

[MetalsGeek]

Check for voltage drop between the battery post and what it should be connected to, while under some load (if possible). Could just be a bum connection, at or within the battery itself. If your voltage drop is external and on the ground side, your Hall FX current sensor could have failed too. Should be fairly easy to find with a voltmeter...

 

[JPinMD]

2022 XLT with 130K plus miles. I do have a 5Yr/150k miles Extended Warranty.

It happened yesterday for the first time. My wife went to get some groceries about a mile from the house. Got back in the Mav and nothing. It had to be jump started to get it home. It is sitting dead in the driveway right now.
The 12V battery was replaced in December and measures 12.8V at the posts. Under the hood however, I'm only getting 3.8V
Before I take it to the dealer, would like some input from folks who have had this problem. Was the issue the cable?
What was the fix?

TIA.

I had the same problem three times since November 2024. The first time I replaced the battery and it worked for 3 months. The 2nd time I replaced the battery with an AGM battery and it worked another 3 months. I took it to the dealer and they had it for a week and found nothing wrong. I suspected the battery cable but was told by Ford that my VIN was not covered under the customer satisfaction program. The 3rd time it happened, on the July 4th weekend, I could jump it but it would no longer start again after the jump so we took it to the dealer and gave it to them dead. This time they finally found the 12V cable problem to be the cause. The workup says they had 12.8V at the battery but just 3V at the battery junction box in the engine compartment. The did a "wiggle test" on the connector, found it to be bad and told me the cable needed to be replaced and it wasn't covered. They had the truck for 2 weeks and $2900 later I picked it up and it's been great since. The cable was less than $500 but snaking it from the back seat to the engine is pretty much a technicians nightmare so labor was the brunt of the charge.

 

[skinnyboy]

$2400 for that job seems like highway robbery. Ford paid 2.2 hrs. labor time.

Cheers.

 

[BlueSpec1]

PDF for the cable overlay: https://dot.report/bulletins/MC-10238866-0001.pdf

 

[BoboysTruck]

I had the same problem three times since November 2024. The first time I replaced the battery and it worked for 3 months. The 2nd time I replaced the battery with an AGM battery and it worked another 3 months. I took it to the dealer and they had it for a week and found nothing wrong. I suspected the battery cable but was told by Ford that my VIN was not covered under the customer satisfaction program. The 3rd time it happened, on the July 4th weekend, I could jump it but it would no longer start again after the jump so we took it to the dealer and gave it to them dead. This time they finally found the 12V cable problem to be the cause. The workup says they had 12.8V at the battery but just 3V at the battery junction box in the engine compartment. The did a "wiggle test" on the connector, found it to be bad and told me the cable needed to be replaced and it wasn't covered. They had the truck for 2 weeks and $2900 later I picked it up and it's been great since. The cable was less than $500 but snaking it from the back seat to the engine is pretty much a technicians nightmare so labor was the brunt of the charge.

What year is your Mav? Is it out of warranty or just not covered?

 

[BoboysTruck]

PDF for the cable overlay: https://dot.report/bulletins/MC-10238866-0001.pdf

Thank you for this. I took a quick look. I think i can do this. I'm not paying $2,900.

I dropped it off at the dealer and first thing they said was it needs a new battery. I said it does not, battery is good. It's an AGM I installed in December. I told him I've been driving it by jump starting it using it's own battery by connecting a jumper cable from battery positive to BJB jumper post. But SA said they can not start troubleshooting without trying battery first because my battery failed their test. I think it's BS. I told him about 22B39. He said they'll check into it.

 

[JPinMD]

What year is your Mav? Is it out of warranty or just not covered?

It’s a 2022 with 76K miles at the time of repair. Definitely out of warranty but might have been covered if the VIN was included in the original notice. It was built in January 22 so it was within the window for covered repair but Ford told me they knew the VINs with the faulty cables and mine wasn’t one of them. Ford and I are no longer on speaking terms…lol. I do love the truck though and am very happy it’s been repaired and humming along with 81K miles now. Have not had any other issues at all before or since.

 

[JPinMD]

Thank you for this. I took a quick look. I think i can do this. I'm not paying $2,900.

I dropped it off at the dealer and first thing they said was it needs a new battery. I said it does not, battery is good. It's an AGM I installed in December. I told him I've been driving it by jump starting it using it's own battery by connecting a jumper cable from battery positive to BJB jumper post. But SA said they can not start troubleshooting without trying battery first because my battery failed their test. I think it's BS. I told him about 22B39. He said they'll check into it.

I went through a very similar process with the dealer which was super frustrating. I also read somewhere that the fix would be in the neighborhood of $3000. I found the same replacement pdf file somewhere on this forum back in March and after looking it over I decided at 72yo with limited tools and patience there’s no way I’m doing it myself so I loaded up on hope and prayer that replacing the battery would fix the problem. Of course, it did not and the rest is history. I wish you the best of luck if you replace the cable yourself.

 

[Manollo3]

It’s a 2022 with 76K miles at the time of repair. Definitely out of warranty but might have been covered if the VIN was included in the original notice. It was built in January 22 so it was within the window for covered repair but Ford told me they knew the VINs with the faulty cables and mine wasn’t one of them. Ford and I are no longer on speaking terms…lol. I do love the truck though and am very happy it’s been repaired and humming along with 81K miles now. Have not had any other issues at all before or since.

He has a 5y/150k extended warranty. Why even bother fixing it yourself. The cost should be covered by the warranty.

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