2006 Ranger Engine Trouble Codes

[achulz]

Hey all, first post to this forum.

I recently picked up a 2006 Ranger XLT, single cab short bed, 2.3L and 5-speed manual. Overall very much enjoying the truck, got a few things done before I register it to my name such as new tires, new windshield, fresh ball joints in the front suspension, small issues like the gauge cluster bulbs being blown out (which I replaced with LEDs), and a nice little head unit upgrade so I can have some modern entertainment features. Great little truck and it's been hauling my motorcycles around to the track like a champ, great gas mileage as well with the 2.3.

Anyways, I have been dealing with some DTCs since I first bought the truck that need to be addressed before it will pass inspection. When I first checked the codes, there were several different codes for the O2 sensor heaters, EGR valve circuit, and evap vent valve. I originally figured it was probably just the O2 sensors that I would need to worry about first, so I ordered those and installed them (both upstream and downstream were replaced with nice Bosch sensors). When I plugged in my scanner after replacing them, the same codes were immediately showing as pending, so I went to the next conclusion that it was something else causing the codes.

Low and behold, I looked up the engine compartment fuse box diagram and noticed fuse 41 controls all three of those circuits (EGR, O2 heaters, and evap vent valve), and sure enough it was blown. I replaced the 15A fuse, cleared the codes again, and for a while (about a week or so) it was fine. No blown fuse, all of the I/M monitors were in ready status after it completed a drive cycle and everything was working smoothly. So I decided to get the inspection done today since everything is in top shape now and it should pass with flying colors.

As soon as I pull into the dealer to get a state inspection done, the fuse blows and the ECM throws all those same codes again. Great, at least I know what the initial cause is, so I replace the fuse again and drive it around the block to get most of the monitors in ready status again and be able to pass. While I was driving around with the scanner plugged in, this time I noticed it only had one pending code, P0452, which is for the evap pressure being low. The fuse did not blow, so the O2 heaters and EGR were in ready status, but evap would not show ready due to the pending code (as well as cat since I only drove it around the block). It ended up failing inspection because of the two monitors in unready status, and during the drive back home the P0452 code stored and threw the light on again. Still no blown fuse, but only one code this time instead of like 10 codes when that fuse 41 blows.

My question is, is it safe to assume the evap vent valve is what's causing the fuse 41 to blow and the DTC? When I research the P0452 code, most of the resolutions point to the pressure sensor in the tank. But that pressure sensor is not controlled by fuse 41, and the fuse blowing tells me that the vent valve is the culprit, possibly being stuck open and making the pressure sensor read low evap pressure.

I ordered a new vent valve, so hopefully that fixes it, but I'm also wondering if there's anything else I should check for? The truck is in great shape overall; it does have quite a bit of miles on the chassis (around 230k) but the engine was replaced at 150k miles and the body, frame, wiring harness, etc. is all in really good shape, no significant rust or corrosion being that it lived in the south its entire life.

 

[RonD]

Welcome to TRS

Be glad you don't have an automatic, fuse 41 also powers the shift solenoids, lol, but you probably would have found fuse 41 sooner

O2 wires are often the reason fuse 41 blows, the wires are near HOT exhaust system so can get too hot and melt a bit causing a partial short in the two heater wires, and that blows the fuse over time
When vehicle is cold run your hand down all the O2 sensor lead wires(just 2 on a 4cyl), you WILL feel any spots that have gotten too hot

If time is not an issue just unplug the Vent solenoid, and drive it a few days and see if Fuse 41 holds up, you will get codes that its unplugged, but if no blown fuse then Vent solenoid is most likely the issue
P0447 Evaporative Emission Control System Vent Control Circuit Open


And just as a heads up, look up codes on a full list like this one first: https://www.therangerstation.com/tech_library/OBD-II_codes.shtml

All computer monitored sensors or controls will have several codes the computer can "choose" from
The codes the computer did NOT choose are as important as the one it did choose, often more important
"Circuit" codes usually mean device or its wires have a problem
"level" codes, i.e. pressure or lean/rich, or ???, usually means the device is working and the system its monitoring has the problem
So you can often eliminate what ITS NOT by the codes the computer didn't choose

 

[achulz]

Welcome to TRS

Be glad you don't have an automatic, fuse 41 also powers the shift solenoids, lol, but you probably would have found fuse 41 sooner

O2 wires are often the reason fuse 41 blows, the wires are near HOT exhaust system so can get too hot and melt a bit causing a partial short in the two heater wires, and that blows the fuse over time
When vehicle is cold run your hand down all the O2 sensor lead wires(just 2 on a 4cyl), you WILL feel any spots that have gotten too hot

If time is not an issue just unplug the Vent solenoid, and drive it a few days and see if Fuse 41 holds up, you will get codes that its unplugged, but if no blown fuse then Vent solenoid is most likely the issue
P0447 Evaporative Emission Control System Vent Control Circuit Open


And just as a heads up, look up codes on a full list like this one first: https://www.therangerstation.com/tech_library/OBD-II_codes.shtml

All computer monitored sensors or controls will have several codes the computer can "choose" from
The codes the computer did NOT choose are as important as the one it did choose, often more important
"Circuit" codes usually mean device or its wires have a problem
"level" codes, i.e. pressure or lean/rich, or ???, usually means the device is working and the system its monitoring has the problem

Yes I'm very much a fan of the 5-speed manual

I'm assuming the vent valve, based on what the picture looks like in the order I placed, is the little solenoid above the vapor canister near the spare tire? I know the purge valve is in the engine bay near the fuse box, but that one appears okay. The vent valve on the other hand looks pretty dirty, being right behind the rear axle and all.

If that is the valve in question, I'll unplug it and see if the fuse continues to blow. From what I've gathered so far it does seem to the be the cause but that should confirm it. I am certain it is not the O2 sensors as they are both brand new, and I made sure to keep the wiring out of the way from the exhaust when I installed them.

 

[RonD]

"New" is another hurtle to jump over now-a-days, lol

30+ years ago "new" meant tested and working
"New" now means "YOU TEST IT, and we will replace it if it doesn't work"

Quality Control means Labor to test random samples after they are made by a machine
And labor is expensive now-a-days
So......................parts can be sold much cheaper if the buyer is the free Quality Control part of the cost, and the company just replaces defective parts under warranty

So grain of salt on "new" parts, or you can chase your tail on troubleshooting if you "assume" a new part works, lol, ask me how I know................oops there's my tail again

 

[achulz]

Quick update, I replaced the vent valve (located on top of the evap canister right above the spare tire) and the good news is the fuse is not blowing and the P0447 code has not appeared, neither have the O2 heater or EGR circuit codes. So that definitely solved that issue. In fact the old vent valve was the original with 230k miles on it, pretty dirty so very likely that was causing the fuse to blow. However, one code is still showing up: P0452. It actually stored the code as soon as I cleared the DTCs so my engine light is still on. I drove about 400 miles yesterday to San Antonio and back and it is the only code that is stored in the ECU.

At least it's only one code now, but I'm not sure what the most likely cause for it is. I believe the fuel sending unit and the filter were replaced recently before I bought the truck, as they both look very new (at least the filter does, I have not dropped the tank but given that the truck has 230k miles it was probably replaced at some point). It also appears to have a non-OEM gas cap. I did not notice any drop in gas mileage, it averaged around 28-29 mpg for the 400 mile trip, even with a 300lb motorcycle in the bed.

Would it be worth replacing the gas cap first and seeing if that alleviates the issue? The code is for low evap pressure, which could likely be the gas cap leaking. I don't smell any gas when I walk around the truck but I do notice a ring of fuel/vapor on the gas cap gasket whenever I fill up. If it is likely the actual evap pressure sensor, where is this sensor located and what does it look like/what is the OEM part number? I searched around RockAuto and multiple parts websites but could not find anything besides the two evap valves, one of which I have already replaced.

Thanks in advance for the advice, hopefully I can get it fixed soon so I can pass inspection without having to pay again and register within 30 days of purchase (unfortunately the seller put the date of sale on there so it put a time limit before I have to pay a penalty for late registration...)

 

[RonD]

You should look at a full list of OBD2 codes when diagnosing one code, seen here: https://www.therangerstation.com/tech_library/OBD-II_codes.shtml

Computer can use these 2 codes if EVAP system won't hold pressure
P0442 Evaporative Emission Control System Leak Detected (small leak)
P0455 Evaporative Emission Control System Leak Detected (gross leak)

And it didn't use them

But that being said you should have a look at the gas caps rubber seal and the filler's rim
Gas cap is not vented, the rubber gasket makes an air tight seal on the filler's rim, or should
So have a close look at the cap, no cracks in plastic or rubber seal

The reason gas cap is suggested for P0452 is because its something any one can do, but its a low probability fault


EVAP system uses engine vacuum to put negative pressure in the gas tank and hold it in
This prevents any gas fumes produced when driving(gas sloshing around) from escaping
There is a pressure sensor on the top of the gas tank
A purge valve and sensor on the engine that applies vacuum to the gas tank

Diagram here: https://www.aa1car.com/library/evapobd2.gif

Obviously if the gas cap was off and EVAP system was in use you should get a P0455 gross leak code
So I would clear P0452 code
Then leave gas cap off and drive(not with a full tank, lol), this is a "sanity test"
I am assuming you can reset codes yourself
You should get ONLY P0455

Not P0452, if you also get P0452 then there is most likely sensor or wiring issue, and could even be a computer issue, extreme long shot

 

[achulz]

You should look at a full list of OBD2 codes when diagnosing one code, seen here: https://www.therangerstation.com/tech_library/OBD-II_codes.shtml

Computer can use these 2 codes if EVAP system won't hold pressure
P0442 Evaporative Emission Control System Leak Detected (small leak)
P0455 Evaporative Emission Control System Leak Detected (gross leak)

And it didn't use them

But that being said you should have a look at the gas caps rubber seal and the filler's rim
Gas cap is not vented, the rubber gasket makes an air tight seal on the filler's rim, or should
So have a close look at the cap, no cracks in plastic or rubber seal

The reason gas cap is suggested for P0452 is because its something any one can do, but its a low probability fault


EVAP system uses engine vacuum to put negative pressure in the gas tank and hold it in
This prevents any gas fumes produced when driving(gas sloshing around) from escaping
There is a pressure sensor on the top of the gas tank
A purge valve and sensor on the engine that applies vacuum to the gas tank

Diagram here: https://www.aa1car.com/library/evapobd2.gif

Obviously if the gas cap was off and EVAP system was in use you should get a P0455 gross leak code
So I would clear P0452 code
Then leave gas cap off and drive(not with a full tank, lol), this is a "sanity test"
I am assuming you can reset codes yourself
You should get ONLY P0455

Not P0452, if you also get P0452 then there is most likely sensor or wiring issue, and could even be a computer issue, extreme long shot

Well talking to the Ford dealer it looks like the pressure sensor is built into the fuel line/evap line assembly. The sensor he is referring to runs along the frame rail from the evap canister up to the front of the vehicle, and the sensor is swaged in to the plastic hose assembly. It is right next to the gas tank with a 3 pin connector. They make aftermarket kits where you cut the hose and put a new sensor in with hose clamps, but I'm not even sure this is the correct part. I cannot find anything else and the dealer wants like 450 bucks for that whole assembly.

I took a look at the wiring, the harness itself is completely fine with no exposed or cut wires, but when I disconnected the sensor a bunch of dirt came out of the connector, so maybe the connector seal is bad. I'll try cleaning the connector and putting dielectric grease and see if it returns the correct readings to the ECU. Will probably probe the wires with the truck to see the sensor's output voltage as well.

For anyone else, here is a link to the Dorman kit (911-260): https://www.rockauto.com/en/partsearch/?partnum=911260

$56 which is much cheaper than the $450 the Ford dealer wanted, even though it is not the OEM way of doing it. If the sensor output is out of range, I'll probably give this a shot.

 

[RonD]

Its not a high pressure hose so cutting and clamping is fine

That does sound more like the purge valve sensor than tank pressure sensor but certainly could be

Purge sensor is on the hose from purge valve(engine bay) to EVAP canister, so 2 hoses connected
The tank pressure sensor just has 1 hose or is just on the tank assembly directly

The two sensor were used for comparison pressures, but one sensor could be used for that

But not well versed in 2006 Rangers specifically

Keep the dielectric grease off the pins and slots of the connector, dielectric grease is used because it does not conduct electricity, so won't cause a short inside a connector and keeps water/dust out, but it also won't allow pins and slot to conduct electricity if too much is used, lol

 

[achulz]

Another update, if anyone is still following.

I tried cleaning the connector with no luck. When I unplugged the sensor to see if any other codes appeared, it also threw a P0453 and the original P0452. With it plugged back in after cleaning and inspecting the wiring, just the P0452 code remained. My evap and cat monitors will not ready because of this stored code, so it is currently impossible for the truck to pass emissions inspection.

Last weekend I drove about 50 miles to the track, truck made it there just fine. Only code that was still stored was the P0452. However, when I went to load up my bike and leave later in the day, the fuse 41 blew again! I noticed the truck having some hesitation at idle, so I plugged in my scanner and sure enough all of the codes pertaining to fuse 41 returned (the hesitation coming from the O2 sensor heaters not functioning from the blown fuse). I replaced the fuse, and upon putting it into gear and getting ready to go, the truck lurched forward with the pedal pressed in and then started to move without me releasing the pedal. I quickly realized the truck wasn't disengaging the clutch completely, so I stopped and had the truck (with my bike in the bed) both towed home as there was nothing I could do in the moment to fix the worn out hydraulics. I have new clutch hydraulics, including the master, concentric slave, and new lines and reservoir ready to install and will be pulling the transmission to get those replaced today. But I am essentially back to square one on this fuse 41 issue.

I have a couple questions about what exactly fuse 41 powers, and how often these circuits are active to determine where the problem lies.

In the fuse diagram chart, it says this fuse is for the oxygen sensor heaters, EGR stepper motor, and the evap canister vent valve. Is this ALL this fuse powers? Does it also power the purge valve in the engine bay or the pressure sensor causing the P0452 code? The only evap component I have replaced is the vent valve that sits above the evap canister, I have not replaced the purge valve in the engine bay by the fuse box.

How often does the vent valve actuate? It seems like the fuse is only blowing once a week, and because the EGR stepper and oxygen sensor heaters are almost always used whenever the truck is running, it seems like the vent valve is still what's causing the fuse to blow.

Some things I am going to try next, after fixing the clutch disengagement issue:
- Testing for continuity across the vent valve connector pins (to test for possible short in wiring harness)
- Cleaning the vent valve connector and inspecting the wiring further down the harness
- Possibly installing a 20a fuse in place of the 15a fuse (I know this is potentially dangerous, but having to replace the fuse every week is very annoying and I want to see if the load itself is just too much for a 15a fuse).

I am open to other suggestions, perhaps a "quick fix" that would allow me to pass inspection and get the truck registered. I am running out of time to not pay a late registration fine, since the seller very kindly put the date of sale on the title (even though I strictly asked them not to).