Majindan
New member
See the pic attached from my '99 fusebox, right hand side close up: the stud on the top right comes from the alt while the bolt head visible towards the bottom comes from the battery.
Hell yes, perfect pics man, thanks!
Emissions tests keep resetting to not ready status...
- Thread starter Majindan
- Start date
Hell yes, perfect pics man, thanks!
octanejunkie
Elite Member
Both of those should be full time hot, engine off or running. Voltage will vary depending on running or off.
Majindan
New member
Ok, so I'm just making sure they actually have power right?
octanejunkie
Elite Member
I don't have an FSM or electrical diagram handy, but those two connections are where the vehicle's electrical system receives incoming power from both the bat and the alt - I suspect the little wire on the lower bolt is what powers the constant hot circuits that would support the ECM and Radio presets, etc.
If someone has more accurate info, please chime in.
Majindan
New member
Sounds really logical to me. I'll test it shortly, thanks again for taking the time.
TheDurk
Elite Member
Well, the alt. only produces power when the engine is running, so the big bolt only has engine-off power with the engine off because the little bolt backfeeds power through the 120A ALT fuse to the big one. Pull the ALT fuse if you don't believe me (not easy to do).
The small bolt feeds the busbar that goes to all the key-off power circuits, including the EFI fuse that feeds the volatile memory in the ECU. The headlights are at the far end of that bar, so they are a good load performance indicator of key-off power.
So basically, if headlights work with engine off, you can forget using a voltmeter on those bolts in this case. You do want to check voltage at both ends of that EFI fuse. If fact, I'd swap in a new one, just to rule out the possibility of a partially burnt one that breaks contact occasionally, and THEN check both ends.
So bascically, if it passes the headlight test and the EFI fuse test, I'd concentrate on the ground side of the circuit.
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Majindan
New member
Update: stopped by Advance otw home, the manager is ASE certified and I explained in detail my issues and he believe the tests are resetting due to the P0440 citing possible vacuum leak(s) as well due to my LTFM topping out around 17-18% I mentioned earlier stating if there is a evap leak, it's causing the tests to keep trying over to finish. He also said catalyst test incomplete bc if the pressure valve under the hood was was compromised it could cause extra fuel vapors to deposit via the catalyst.
So now I'm looking for a custom PID to aid me in diagnosing via Torque where the hell this evap leak is. Any pointers or suggestions that don't include a smoke test?
So now I'm looking for a custom PID to aid me in diagnosing via Torque where the hell this evap leak is. Any pointers or suggestions that don't include a smoke test?
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TheDurk
Elite Member
Not sure I buy it. How does he explain the radio reset? And how in hell do the fuel vapors from the tank get to the cat converter in the exhaust system? I have not seen or read about that kind of linkage between the EVAP and CATALYST monitors. i have had fails on both while the other was READY. Anybody else?
P0440 is you have atmospheric pressure in the evap system, so those vapors are being lost to the atmosphere. SMH...
Here is one P0440 tip from the FSM. I forget if Torque gets you to the freeze frame. I haven't had to do it..Otherwise, it's just a matter of checking all the hose connections between charcoal canister and fuel tank and looking for cracks in the canister case--all of which is a lot easier with the smoke machine. I doubt Torque or any other electronic system can do much to narrow it down, but EVAP is not an area I think I'm strong in..
P.S. I just built my own smoke machine for less then $15. Worked great to find a vacuum leak on my son's Mercedes C300.
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Majindan
New member
Evap is far from my strong area too obviously lol, a fun learning experience. (it's not)
19963.4lsr5
New member
Me too, I don't like how Torque displays the readiness monitors. It leaves me wondering what should be there. My Innova 3130 only shows what's required and if it's flashing it's not set. Plus I have a indicator just to show the readiness monitors are set.
The PCM gets all its power from the engine bay and it's wiring so the radio screwing up could just be a problem with its instal or something under the dash.
Your LTFT being that high and it's having to add almost 20% extra fuel is concerning.
Unless your running a glass pack with a very good flowing exhaust something is going on. It's getting extra air into the engine (vacuum leak and not a small one, a sensor is giving bad info to the PCM causing it to choose a leaner fuel map and the O2 sensor is having to correct for it, or there is a fuel delivery problem)
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fourfive
Senior Member
So you do have a P0440 code? If you do & the only thing that was done previously was to clear the code but the OBII is showing not ready, that probably means the P0440 is pending which is why it is not ready. A P0440 leak can come from a number of different locations in the evap system such as hose connections, worn hoses, charcoal canister, overfill check valve on top of the gas tank if you have an 01-02, etc. My fix to P0440 was the overfill check valve. I spent MANY weekends trying to trouble shoot where the leak was coming from including using a homemade smoke machine. I was able to pretty confidently rule in the overfill check valve after all the testing I did. Replaced it and the code has been absent since November 2016. Although I don't have any pending codes, my OBDII will periodically show ready but usually not ready. I'll go through the drive cycles until it states it's ready but after a while it will show not ready again. That part is still a mystery to me.
hugo2go
New member
I had the same issue happen where the smog monitors were not "ready".
No CELs, but my fix was just that the coolant system had air in it, which caused the Coolant temp sensor to read incorrectly. Once the system was bled, the monitors kicked on and passed Cali smog with flying colors with 280K on the odometer.
No CELs, but my fix was just that the coolant system had air in it, which caused the Coolant temp sensor to read incorrectly. Once the system was bled, the monitors kicked on and passed Cali smog with flying colors with 280K on the odometer.
19963.4lsr5
New member
My EVAP monitor not setting after the engine swap was a bad/incorrect gas cap.
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Majindan
New member
Update: It was just the Evap/Cat monitors showing not ready, and as of my lunch break today, they were all reset again. Checked volts on battery and the two bolts in the under hood fuse box and they checked out fine. Will swap the OBD port fuse and clean the MAF tonight as it's been a good year since I've done that while I'm in there.
Question: After I'd cleared emissions last year, I was under the dash and cut the wire for the DRL as headlights on during daytime annoys me...is it possible I may have inadvertently partially snipped another wire while under there or if the DRL wire ends are somehow bumping together causing power surges or something?
Still weird how my radio reverts back to the factory station of 88.something occasionally when I start the truck sometimes...I may pull the head unit and double check the wiring. I'm about at a loss though, because even if I do have an evap leak, the catalyst test should still clear even if the evap test keeps testing right? And no CEL of course.
Edit; Google brought me to some random Ford forum where I read about "KAM (Keep-Alive Memory) circuit to the PCM" where they talked about test pin 16 in the OBD port, thoughts?
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Majindan
New member
I put an OEM cap on last fall when I bought it, and upon visual inspection it's still like new. How much flex should there be around the gas nozzle itself?
Majindan
New member
Update: Last night I found a little gray wire with black stripe that was cut going into the harness across from my DRL box under the dash, fixed that. Also, took out the air intake tubing/boxes to clean the throttle and MAF and after cleaning them inspected all plastics and vacuum lines for breaks etc. Discovered the rectangular box between the MAF and throttle intake (sound compressor silencer?) had a little bit of oil seeping between the lower seam where the plastic was joined. Throttle cleaner followed by Gorilla Glue to re-seal.
Drove to work, LTFM has been peaking at 17-20% for the past week and didn't climb higher than about 7% otw to work, about a 20-minute drive, so something is fixed lol.
Thinking about pulling the negative battery terminal at break to properly reset the emissions testing memory and I also pulled the 15w fuse to the radio/aux power outlets just in case (see initial post regarding why radio).
Drove to work, LTFM has been peaking at 17-20% for the past week and didn't climb higher than about 7% otw to work, about a 20-minute drive, so something is fixed lol.
Thinking about pulling the negative battery terminal at break to properly reset the emissions testing memory and I also pulled the 15w fuse to the radio/aux power outlets just in case (see initial post regarding why radio).
instead of saying "they were all reset again", just say that "IT" or "the evap reediness monitor" was reset.
when you say "they were all reset" makes it sound like all of them were reset.
with that being said, evap's are a pain in the butt.
"correlation does not imply causation" meaning that the radio might be a completely different situation.
If you had or can get access to a diagnostic scanner like a solus ultra. you would then be able to selectively test each component of the evap system and see real time data. that might be your best bet as to why its doing what its doing.
when you say "they were all reset" makes it sound like all of them were reset.
with that being said, evap's are a pain in the butt.
"correlation does not imply causation" meaning that the radio might be a completely different situation.
If you had or can get access to a diagnostic scanner like a solus ultra. you would then be able to selectively test each component of the evap system and see real time data. that might be your best bet as to why its doing what its doing.
