Sponsored

Hood Ajar, Ambient Temperature not working

Hootbro

Well-Known Member
Joined
Apr 13, 2019
Threads
32
Messages
6,219
Reaction score
10,306
Location
Delaware
Vehicle(s)
2022 Gladiator Rubicon
I would concentrate on looking at your XY103A connector. Pin 3, 4 & 5 cover all three circuits you are having an issue with. There might be some green puss corrosion on the contacts or at the crimps of the terminals. Might want to do a tug test of the wires at connector, both sides male and female.
Jeep Gladiator Hood Ajar, Ambient Temperature not working XY103A
Sponsored

 
OP
OP
jeep1

jeep1

Well-Known Member
First Name
Wayne
Joined
Feb 9, 2022
Threads
5
Messages
174
Reaction score
238
Location
Chilliwack, BC
Vehicle(s)
2020 JLUR, 2024 JLURX
I would concentrate on looking at your XY103A connector. Pin 3, 4 & 5 cover all three circuits you are having an issue with. There might be some green puss corrosion on the contacts or at the crimps of the terminals. Might want to do a tug test of the wires at connector, both sides male and female.
Jeep Gladiator Hood Ajar, Ambient Temperature not working XY103A
Yep... done that. No corrosion and the pins are well seated in the plugs.

It's because it's those three wires that I've been looking under the dash as well since all three run to the C4/D connector. The Sensor Ground (Pin 5) is shared with the Hood Ajar Switch and the AAT which made it the first thing I tested for.

It would make sense that it's under the hood somewhere. Will keep looking for the not-obvious
 
OP
OP
jeep1

jeep1

Well-Known Member
First Name
Wayne
Joined
Feb 9, 2022
Threads
5
Messages
174
Reaction score
238
Location
Chilliwack, BC
Vehicle(s)
2020 JLUR, 2024 JLURX
I would honestly test from the switch connector side. It should give the same ability to test in terms of seeing a short. Plus, chances are very high that if something's gone wrong with the wiring, it's happened on the engine bay side anyway. I wouldn't imagine you need to go under the dash again unless you have absolutely no other options to test.
I pulled the plugs off the two hood switches and the temperature sensor ... good continuity between those three plugs and the XY103 plug. No sign of a short there. On the off chance it was the temperature sensor itself, Ieft that unplugged but the hood sensors are still throwing errors. Also left the two hood switches disconnected on the off chance one of those was shorting out...

I'm beginning to wonder if the short or broken circuit is actually at the BCP but going to retest from the BCP plugs out to the final plugs at the sensor and two switches tomorrow.

Jeep Gladiator Hood Ajar, Ambient Temperature not working Screenshot 2023-05-07 at 3.37.42 PM
Jeep Gladiator Hood Ajar, Ambient Temperature not working Screenshot 2023-05-07 at 3.39.27 PM
 

sharpsicle

Well-Known Member
Joined
Apr 29, 2021
Threads
13
Messages
2,154
Reaction score
4,878
Location
Tampa, FL / Milwaukee, WI
Vehicle(s)
2020 Gladiator Overland, 2002 VTX1800
How exactly are you testing here? Sounds like you're testing the length of the cable, and again, continuity there does not tell you about a short, so I'm curious how you're going from one to determine the other. Also, are you clearing codes as you do this and they come back? Or are they just hanging out and you're waiting to see if they go away on their own?

Also, if you tested the switches and they're functioning normally, why leave them disconnected if you aren't testing them or their connections? Unless you still think they might be the problem and are eliminating them, but still that's going to create an error condition.

I think you need to slow it down and get much more methodical if you want to chase this down right. Test one thing at a time, change only one thing at a time, and observe the results. If you detect a problem, fix the observed issue, then continue on. Eliminate the possibilities one by one. Right now I think you're creating too many moving parts and aren't actually getting results you can make decisions on.
 
Last edited:

ShadowsPapa

Well-Known Member
First Name
Bill
Joined
Oct 12, 2019
Threads
178
Messages
29,083
Reaction score
34,567
Location
Runnells, Iowa
Vehicle(s)
'22 JTO, '23 JLU, '82 SX4, '73 P. Cardin Javelin
Occupation
Retired auto mechanic, frmr gov't ntwrk security admin
Vehicle Showcase
3
How exactly are you testing here? Sounds like you're testing the length of the cable, and again, continuity there does not tell you about a short, so I'm curious how you're going from one to determine the other. Also, are you clearing codes as you do this and they come back? Or are they just hanging out and you're waiting to see if they go away on their own?

Also, if you tested the switches and they're functioning normally, why leave them disconnected if you aren't testing them or their connections? Unless you still think they might be the problem and are eliminating them, but still that's going to create an error condition.

I think you need to slow it down and get much more methodical if you want to chase this down right. Test one thing at a time, change only one thing at a time, and observe the results. If you detect a problem, fix the observed issue, then continue on. Eliminate the possibilities one by one. Right now I think you're creating too many moving parts and aren't actually getting results you can make decisions on.
Bingo - fix one thing at a time. You said it. Troubleshooting will look for commonalities and lead for places to look, but pic just one of them to fix at one time.

Choose one, ignore the others for now. Yes, there are things in common but trying to find them all at once can get things twisted.
Likely once one is resolved, the others will fall in line.

There are "grounds" and there are "shorts" and so on - one isn't always the other.
Check not only for continuity of the wires pin to pin, but for connection to ground, as in a wire pinched somewhere.

Frankly, if the aux battery is replaced using the recommended method, it can't impact anything else - at least not easily.

Like pointed out, the temp sensor is on the driver side, up by the grill and not far from the hood switches - inches apart.
You'll definitely want that all fixed because if that ambient temp sensor isn't right, your HVAC will drive you batty.

And gotta stress, continuity shows only end-to-end conductivity, it doesn't tell you if it's also making contact with ground or another circuit.
 

Sponsored

b-roc

Well-Known Member
First Name
Broc
Joined
Aug 28, 2020
Threads
5
Messages
255
Reaction score
359
Location
Denver, CO
Vehicle(s)
2021 JTM
Oh you didn't come off as stirring the pot at all. And yes, that is what I've been doing with the multimeter. I hadn't considered a short so wasn't specifically looking for it. Will need to pull the plugs and start retesting.

Getting at the C1/A and C4/D connectors at BCP is a pain in the ass.. up under the dash, not enough room for two hands etc.. Definitely easier with the door off so you can get better angles at everything. C4 isn't awful but I pretty much have to pull all the plugs and then remove the BCP from the body before I can get at the little lock pin on C1. My back and hands aren't as young as they once were!
A few things
1) After multiple small projects having me work in the driverside footwell/dash area, I have started just pulling the driver's seat from the start now
2) Sounds like this is not your first electronics troubleshooting experience. I would say to continue what you are doing, but once you get to deeper troubleshooting (if you are going to continue doing it yourself) then consider buying the male and female connectors for the connections that you are troubleshooting and then making a one-to-one harness. This can allow you to more easily test for more complicated patterns/problems. The next level of complexity is instead of a one-to-one harness that you can hack away at that you purchase or make an electrical breakout box (https://en.wikipedia.org/wiki/Breakout_box) ... With this you would make a few test harnesses with the mopar connector at one end and whatever the breakout box uses at the other (picture the breakout box as sitting in the middle of a one-to-one harness (a breakout box allows for measurements on any wire and most will allow you to make or break continuity with either jumpers or switches) ... this plus a multimeter with max/min hold (or oscilloscope, or other device that can detect and record transients) will allow you to catch transients or oscillating signals
3) If I had to guess, the most likely wire involved is the shared ground (just as you suspected) and there is a short to a non-ground wire somewhere. Since you said that you have already spliced into the AAT, you could start by monitoring the ground side of that on either side of the splice relative to ground (using max/min hold) if you find something, then you would at least have narrowed down which side of the harness to trace.
4) An alternative test would be to splice the the ground wire directly to ground to force the signal low (there are a few ways to do this all with their own merits ... just be mindful of potential unexpected currents if there is a short somewhere). I would expect the ajar warning to go away, but I would expect the AAT error to persist.

Edit: Disconnect the hood switches and AAT for test described in 3 (i.e. isolate the signal ground wire).
 
Last edited:
OP
OP
jeep1

jeep1

Well-Known Member
First Name
Wayne
Joined
Feb 9, 2022
Threads
5
Messages
174
Reaction score
238
Location
Chilliwack, BC
Vehicle(s)
2020 JLUR, 2024 JLURX
And gotta stress, continuity shows only end-to-end conductivity, it doesn't tell you if it's also making contact with ground or another circuit.
Bingo - fix one thing at a time. You said it. Troubleshooting will look for commonalities and lead for places to look, but pic just one of them to fix at one time.
Good advice of course. I’m running down the hood sensor since it’s the easiest to debug. I’ve got a decent multimeter but it’s been years since I’ve had to debug auto wiring. Normally I just replace a harnesses and call it a day.

And yes …. Building a full test harness has crossed my mind.
 

Gladbrennan

Banned
Banned
First Name
Brennan
Joined
Oct 8, 2022
Threads
0
Messages
62
Reaction score
20
Location
Connecticut
Vehicle(s)
2021 Gladiator Diesel
My point made. At least this time you learned how to spell check. Now stop posting just to cause trouble.
Your point was made,. I dint ackwally spel chek dat time i just thot reel hard. Seems like you are continuing to cause the trouble Doug.
 

Dougstdig

Well-Known Member
First Name
Doug
Joined
Sep 5, 2017
Threads
19
Messages
1,350
Reaction score
1,285
Location
FL
Vehicle(s)
‘21 JTRD - '08 Dodge Ram 2500 4x4
Your point was made,. I dint ackwally spel chek dat time i just thot reel hard. Seems like you are continuing to cause the trouble Doug.
I won't be responding you in this thread again, as I've done a quick review of your posts in this forum. The vast majority of which, seem to be condescending and argumentative. Whether this is just because you don't know how to communicate, it's the only way you feel that you can have a cloudy sense of power over someone else or something else I won't spend the time to figure out... You seem to have an issue communicating with others and I hope you find a remedy to your affliction. Good luck.
 

Gladbrennan

Banned
Banned
First Name
Brennan
Joined
Oct 8, 2022
Threads
0
Messages
62
Reaction score
20
Location
Connecticut
Vehicle(s)
2021 Gladiator Diesel
I'll work on it for you Doug. You just responded again, stop.
 
Last edited:

Sponsored

OP
OP
jeep1

jeep1

Well-Known Member
First Name
Wayne
Joined
Feb 9, 2022
Threads
5
Messages
174
Reaction score
238
Location
Chilliwack, BC
Vehicle(s)
2020 JLUR, 2024 JLURX
A few things
3) If I had to guess, the most likely wire involved is the shared ground (just as you suspected) and there is a short to a non-ground wire somewhere. Since you said that you have already spliced into the AAT, you could start by monitoring the ground side of that on either side of the splice relative to ground (using max/min hold) if you find something, then you would at least have narrowed down which side of the harness to trace.
4) An alternative test would be to splice the the ground wire directly to ground to force the signal low (there are a few ways to do this all with their own merits ... just be mindful of potential unexpected currents if there is a short somewhere). I would expect the ajar warning to go away, but I would expect the AAT error to persist.
As you suspected the "what" is the "sensor ground" wire. The "why" part still eludes me. From the hood switch side of things I'm seeing 14v (as expected) on the hood switch line but the sensor ground shows open. And I've tested both from the switch plug itself and from the connector to the body harness (XY103) so its not the front harness or a faulty ATT etc...

On our JL, I see 14v and sensor ground does go to ground. And yes, if I bypass the sensor ground and just go directly to ground, the switch works as expected and the truck thinks the hood is closed.

Here's where I run out of ideas. On the off chance I had a nick somewhere or otherwise screwed something up, I reran the ground wire, redid the connections etc.... I don't have a short to ground and I'm not seeing any transient voltages, so I'm pretty confident that the sensor ground wire itself is fine.

From the BCM connector (C4/D) I can see both the hood switch and the ATT. I'm seeing 10ohms on the ATT, exactly the same as I do if I check the sensor directly. Heat it up, and the resistance changes. Same thing with the hood switch.. roughly 500ohms open, 1kohm closed. (there is a resister in parallel to the switch apparently).

I've checked the pins on the BCM, nothing bent... I've checked and reseated the sensor ground pin on the BCM connector.. everything appears tight and in place. Wires aren't stretched oddly or thing that would lead me to believe that just the act of seating the plug makes any difference ....
 

b-roc

Well-Known Member
First Name
Broc
Joined
Aug 28, 2020
Threads
5
Messages
255
Reaction score
359
Location
Denver, CO
Vehicle(s)
2021 JTM
I am certain that you have looked at the diagrams more closely than I ... so make sure that my assumptions are correct... neither the aat or the switch provide ground to the signal ground wire by design ... if true, then the design is that the bcm provides the ground path ... In that case, I would check the bcm ground pin vs ground ... based off what you are describing, I am guessing that the bcm isn't supplying the ground... and since you have a jl to compare against you could check that too (although I don't know if they are the same/similar enough to be meaningful)... if my guess pans out, I would check for a cold solder on the bcm board to the connector for the ground pin first ... good luck!
 
OP
OP
jeep1

jeep1

Well-Known Member
First Name
Wayne
Joined
Feb 9, 2022
Threads
5
Messages
174
Reaction score
238
Location
Chilliwack, BC
Vehicle(s)
2020 JLUR, 2024 JLURX
the design is that the bcm provides the ground path
That seems to be the case. Definitely isn't tied to the two "input" grounds on the power side of the BCM.

I would check for a cold solder on the bcm board to the connector first ... good luck!
Yeah.. that's probably my last step before I break down and take the truck into the dealer and likely get the BCM replaced, which will lead to all sorts of nonsense with aftermarket parts, upgraded AV/HVAC, power locks, none of which will be in the base codes they are going to program it with.

Thanks for the help.
 

b-roc

Well-Known Member
First Name
Broc
Joined
Aug 28, 2020
Threads
5
Messages
255
Reaction score
359
Location
Denver, CO
Vehicle(s)
2021 JTM
That seems to be the case. Definitely isn't tied to the two "input" grounds on the power side of the BCM.



Yeah.. that's probably my last step before I break down and take the truck into the dealer and likely get the BCM replaced, which will lead to all sorts of nonsense with aftermarket parts, upgraded AV/HVAC, power locks, none of which will be in the base codes they are going to program it with.

Thanks for the help.
Glad to help ... only other easy'ish thought if it's the bcm ... a blown (or cold soldered) diode to ground leading to a floating ground
 
OP
OP
jeep1

jeep1

Well-Known Member
First Name
Wayne
Joined
Feb 9, 2022
Threads
5
Messages
174
Reaction score
238
Location
Chilliwack, BC
Vehicle(s)
2020 JLUR, 2024 JLURX
So turns out it was the BCM after all... $700 later, dealer programmed and swapped in the new BCM and all is good in the world again.
Sponsored

 
 



Top