Just tried to get my Ranger through MD emissions and again it failed. Originally I had the error code Keep Memory Alive voltage low. I fixed that issue and it successfully turned off my check engine light. Now it comes up with a not enough codes error, which emissions Originally tried blaming on the battery being disconnected recently. However a scan tool can't even communicate with the computer, it won't connect. I checked the fuse, it's good, I checked pin 16 it's getting a proper 12v. I cleaned the port with contact cleaner and all the pins look good. Has anyone ran into a problem like this before?

 

how recently was the battery disconnected? If you disconnect the battery it does wipe the readiness monitors and you need to do a couple drive cycles to get them to complete.

what is the error message you get when a scan tool is hooked up?

 

I haven't disconnected the battery in months. Autozone's scan tool can't even connect and emissions gives me a 99999 code. Too many obd monitors are not ready.

 

that would tell me that the truck just needs driven more or you have another problem that won't allow it to run a drive cycle . according to the paper, it was able to communicate

 

Driven the truck 2000 miles this week. I drive it every day and have for months since the last time the battery was unhooked. If it can't run a proper cycle could my computer be bad?

 

it could be but not very likely,

my recommendation would be to find a good reputable local shop whether its a ford dealer or independent and have them diagnose it. We ran into this a couple years ago with a used F150, i forget exactly what the fix was but i think it was an O2 sensor, i think

 

I would disconnect battery again, and leave it disconnected for at least 5 minutes
Then reconnect battery and turn on the key, do not start engine yet
Test battery voltage with key on
12.8v to 12.3v is OK
12.2v or less means battery is too low, when you start the engine the voltage will drop below 10volts and modules can start to reset themselves which causes issues, called "brown outs" when "computer circuits" get low voltage instead of no voltage(black outs)

A new battery will be 12.8volts
3 year old battery 12.5volts
5/6 year old battery 12.3volts and time to shop for battery sales

12.2volts or less is a failed battery, change it now
This can be from a failing Charging system

So if engine starts test battery voltage after engine is started
14.2 to 14.8volts is expected
After engine has been running for 10minutes or so 13.5v to 13.8volts is expected

 

Battery isn't even a year old. When tested the volts were at 12.68. I'm leaning towards possibly the o2 sensors. The truck has 3 sensors and all are original.

 

O2 sensors are the only sensors that wear out, 100k miles or 12 years which ever comes first
They are coated with a chemical that detects Oxygen, chemical gets used up

 

this is your solution.

 

Its actually the first thing to do for ALL electronics that run any software, which all do, Reboot with factory software, i.e. unplug from power and plug back in

Cable(satellite) box acting up.......unplug and plug back in
Home computer acting up.....turn off and back on
Smart Phone acting up........turn off and back on(and you often need to remove battery power to do full reboot)
Engine computer acting up......turn off and back on(removing battery power is the only way on this one)

If it has any form of electronics, REBOOT is the first thing to do, lol

For a "solution" you need to first ID a specific problem

 

Three people were in a car one day when the car suddenly died.

The driver, who is a plumber, stated, "It sounds like the fuel pump... let's replace that."

One passenger, who is an electrician, said, "No, I don't think it's getting any spark. Replace the coil."

The second passenger, who is a computer programmer, said, "You're both wrong. It's the computer. Let's just get out and back in again."

 

I'll try it, but when I fixed the Keep memory Alive issue I did this. Unplugged the battery for about 10 minutes. I even connected the pos and neg leads to fully discharge everything. It cleared all codes but now it seems to not want to run a full cycle. However I will try resetting everything again before replacing all the O2 sensors