• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Contuniues Check Engine Light need help to fix.....


SRD

Member
Joined
Jun 18, 2021
Messages
82
Reaction score
17
Points
8
Location
Las Vegas
Vehicle Year
1999
Make / Model
Ford Ranger XLT
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
I don't think so. I just did another test to make sure and got 33.4v.......I take it this is not normal? Or am I doing something wrong when taking the readings?
 

Attachments



pentode

Well-Known Member
Supporting Member
Ham Radio Operator
Joined
Apr 30, 2024
Messages
231
Reaction score
270
Points
63
Location
Moncton NB
Vehicle Year
2005
Make / Model
Ford Ranger
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
You should be seeing 0V on that gray/red ground wire. I’m scratching my head to understand where 33V would be coming from. Try changing to ohms and measure the same points. Should be very close to zero ohms.
 
Last edited:

pentode

Well-Known Member
Supporting Member
Ham Radio Operator
Joined
Apr 30, 2024
Messages
231
Reaction score
270
Points
63
Location
Moncton NB
Vehicle Year
2005
Make / Model
Ford Ranger
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Is there an indicator at the top of the meter that says it’s reading millivolts? I can’t see on my screen.
If so that’s probably ok but might be not the greatest ground

edit: ah yes I turned the brightness way up and it’s indeed reading millivolts not volts

edit2: so your power and ground are basically good, just need to figure out why the sensor is pegged at 5V
 

pentode

Well-Known Member
Supporting Member
Ham Radio Operator
Joined
Apr 30, 2024
Messages
231
Reaction score
270
Points
63
Location
Moncton NB
Vehicle Year
2005
Make / Model
Ford Ranger
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
I would suggest reading the voltage on the green signal wire with the connector unplugged. I don’t have the schematic in front of me but I’m guessing it should read zero in that state. If it still reads 5V you either have a wiring fault or a pcm fault. If it reads zero the sensor might be defective/damaged. either way it’s a good data point to have.
 

SRD

Member
Joined
Jun 18, 2021
Messages
82
Reaction score
17
Points
8
Location
Las Vegas
Vehicle Year
1999
Make / Model
Ford Ranger XLT
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Ok. I unconnected the DPFE pigtail and tested the Green wire again with Key On. I got 5.08v...set the meter to DC voltage on the meter.

Red is still the same unplugged...at 33v.....or Mili-Volts?

Thanks for helping me figure this out! I know your time is valuable.

-SRD
 

pentode

Well-Known Member
Supporting Member
Ham Radio Operator
Joined
Apr 30, 2024
Messages
231
Reaction score
270
Points
63
Location
Moncton NB
Vehicle Year
2005
Make / Model
Ford Ranger
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
I'm happy to be helpful if I can. I need to dig out the wiring diagram again but unless there's something I'm missing, I would think the most likely cause of that 5V reading would be a short between the 5V supply wire and the signal wire. I don't see anything that looks like a likely short in your photos but it could be somewhere else along the harness.
Let me check the wiring diagram again before i give out bad advice. 😀
 

Mechrick

Active Member
Joined
Jan 10, 2020
Messages
175
Reaction score
94
Points
28
Location
Las Vegas
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
An unterminated signal wire will float up to 5 volts.

Try grounding the gray/red wire to battery negative with the sensor plugged in and recheck the signal wire. You should be reading less than 2 volts.
 

pentode

Well-Known Member
Supporting Member
Ham Radio Operator
Joined
Apr 30, 2024
Messages
231
Reaction score
270
Points
63
Location
Moncton NB
Vehicle Year
2005
Make / Model
Ford Ranger
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
An unterminated signal wire will float up to 5 volts.

Try grounding the gray/red wire to battery negative with the sensor plugged in and recheck the signal wire. You should be reading less than 2 volts.
Thanks, you had mentioned that earlier in the thread and I spaced on that detail.
 

SRD

Member
Joined
Jun 18, 2021
Messages
82
Reaction score
17
Points
8
Location
Las Vegas
Vehicle Year
1999
Make / Model
Ford Ranger XLT
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Ok....with the Key On. I tested the Red/Grey wire again with the Black end on the NEG Battery terminal and the Red on the Red/Grey wire.

The result was 33.4 mv on DC Voltage...it bounces a bit but stops there for a while before bouncing again....

*Another symptom I have is all 4 Orange indicator Lamps light up on my dash when I turn on the Headlights. All of them; but only with lights ON. If that's anything.

Thanks for all the Help!

-SRD
 

Mechrick

Active Member
Joined
Jan 10, 2020
Messages
175
Reaction score
94
Points
28
Location
Las Vegas
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
The gray/red wire, if attached to batt negative, is ground. Don't believe the meter.

Check the signal wire with the gray/red grounded. You should read less than 2 volts.
 

SRD

Member
Joined
Jun 18, 2021
Messages
82
Reaction score
17
Points
8
Location
Las Vegas
Vehicle Year
1999
Make / Model
Ford Ranger XLT
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Hello. Ok, thanks for the reply. Here, I am lost in the process. I do not understand the instructions.

*Did I not do something right? I am not sure what you mean by "With the red/grey grounded"...test the green wire also? How to test both at the same time?

Sorry, I am not familiar with electrical testing at all; this is my first time so little confused about what you are asking me.

Thanks.

SRD
 

Mechrick

Active Member
Joined
Jan 10, 2020
Messages
175
Reaction score
94
Points
28
Location
Las Vegas
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
What you'll be doing is supplying your own ground since that is the meter reading that doesn't make sense. Then check the signal wire for proper voltage. Signal wire should be brown/light green.
 

SRD

Member
Joined
Jun 18, 2021
Messages
82
Reaction score
17
Points
8
Location
Las Vegas
Vehicle Year
1999
Make / Model
Ford Ranger XLT
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Ok..I do not know how to supply my own ground? How to do that before testing?

I can put the Black probe on the Neg Battery terminal and a red one on any wire and get a reading...but after that, I am unclear on what to do to get a proper test?

Test the light green wire after I ground the other red/grey wire? Just Trying to understand..

Thanks. I am a little slow....but working on it.
 

SRD

Member
Joined
Jun 18, 2021
Messages
82
Reaction score
17
Points
8
Location
Las Vegas
Vehicle Year
1999
Make / Model
Ford Ranger XLT
Engine Type
3.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Hello. I appreciate all the advice. I get confused over all the instructions. So, I have these questions.

#1: I tested all 3 wires and got all 3 readings with the Key ON and Black Probe to the NEG Battery Terminal and Red on each wire.

#2: What would be the next step and why? How would I do the next step?

#3: I understand things read Volts...I hear it should read this or the 5v or 2v etc........but do not know what it means if it does not read this or that.....if the readings are off or incorrect then where does that lead me?

I have to digest the steps one by one not knowing much about how it all works.....any advice on a step-by-step basis would be appreciated.

Thanks.

-SRD
 
Last edited:

Mechrick

Active Member
Joined
Jan 10, 2020
Messages
175
Reaction score
94
Points
28
Location
Las Vegas
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
Run a separate wire from battery negative to the gray/red wire. Then check the brown/Lt green wire with your meter (black to battery negative and red to brown/ Lt green). Do this with the connector plugged in.
 

Sponsored Ad


Sponsored Ad

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Truck of The Month


TexasDuck66
July Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top