What do these error codes mean?
Thread Starter
|
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
What do these error codes mean?
I decided to check the computer error codes in my 87 ranger XLT today. I only got engine-running codes, because the engine off codes didn't seem to make any sense, or I just fail at counting them. With the engine running, I got the following codes
12 - Cannot control RPM during ER Self-Test high RPM check. (would this be cause by a sticking idle-air-valve?)
21 - ECT out of self test range 0.3 to 3.7 volts. (what is this?)
22 - MAP/BP sensor out of self test range. (I got manifold pressure sensor from googling, is this correct?)
41 - No HEGO switching detected always lean (right side). (what this?)
77 - System failed to recognize brief WOT during Dynamic Response Test (user error). (Looks like I didn't gun the engine after starting it?)
I'm not sure if these are all the error codes, but I will check again later. But from what I can tell, basically every sensor on the engine is dead?
12 - Cannot control RPM during ER Self-Test high RPM check. (would this be cause by a sticking idle-air-valve?)
21 - ECT out of self test range 0.3 to 3.7 volts. (what is this?)
22 - MAP/BP sensor out of self test range. (I got manifold pressure sensor from googling, is this correct?)
41 - No HEGO switching detected always lean (right side). (what this?)
77 - System failed to recognize brief WOT during Dynamic Response Test (user error). (Looks like I didn't gun the engine after starting it?)
I'm not sure if these are all the error codes, but I will check again later. But from what I can tell, basically every sensor on the engine is dead?
Cargo Master
Joined: May 2001
Posts: 3,208
Likes: 13
12 could be a sticking /dirty IAC. Try cleaning it with sensor safe solvent.
21 engine coolant temp sensor is probably bad. Not to unusual for this model.
22 I would fix 21 and see if 22 goes away first but a bad MAP sensor is possible
41 heated oxygen sensor is not working. If the truck has a lot miles then it probably needs to be replaced.
77 ignore it you didn't step on the acceraltor pedal when you should have while
running the test.
Your truck isn't ever making it to closed loop mode (computer setting the fuel air mixture so you are running in set parm mode which hurts economy and causse driveability problems. The only question I have did you let it warm up good before starting the Key On Engine Running test. It must be up to temp berfore the results are accurate. What codes did you get for a Key On Engine Off test. They do make a fairly cheap lcd tester so you don't have to count cel flashes.
21 engine coolant temp sensor is probably bad. Not to unusual for this model.
22 I would fix 21 and see if 22 goes away first but a bad MAP sensor is possible
41 heated oxygen sensor is not working. If the truck has a lot miles then it probably needs to be replaced.
77 ignore it you didn't step on the acceraltor pedal when you should have while
running the test.
Your truck isn't ever making it to closed loop mode (computer setting the fuel air mixture so you are running in set parm mode which hurts economy and causse driveability problems. The only question I have did you let it warm up good before starting the Key On Engine Running test. It must be up to temp berfore the results are accurate. What codes did you get for a Key On Engine Off test. They do make a fairly cheap lcd tester so you don't have to count cel flashes.
Thread Starter
|
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
Originally Posted by wtroger
12 could be a sticking /dirty IAC. Try cleaning it with sensor safe solvent.
21 engine coolant temp sensor is probably bad. Not to unusual for this model.
22 I would fix 21 and see if 22 goes away first but a bad MAP sensor is possible
41 heated oxygen sensor is not working. If the truck has a lot miles then it probably needs to be replaced.
77 ignore it you didn't step on the acceraltor pedal when you should have while
running the test.
Your truck isn't ever making it to closed loop mode (computer setting the fuel air mixture so you are running in set parm mode which hurts economy and causse driveability problems. The only question I have did you let it warm up good before starting the Key On Engine Running test. It must be up to temp berfore the results are accurate. What codes did you get for a Key On Engine Off test. They do make a fairly cheap lcd tester so you don't have to count cel flashes.
21 engine coolant temp sensor is probably bad. Not to unusual for this model.
22 I would fix 21 and see if 22 goes away first but a bad MAP sensor is possible
41 heated oxygen sensor is not working. If the truck has a lot miles then it probably needs to be replaced.
77 ignore it you didn't step on the acceraltor pedal when you should have while
running the test.
Your truck isn't ever making it to closed loop mode (computer setting the fuel air mixture so you are running in set parm mode which hurts economy and causse driveability problems. The only question I have did you let it warm up good before starting the Key On Engine Running test. It must be up to temp berfore the results are accurate. What codes did you get for a Key On Engine Off test. They do make a fairly cheap lcd tester so you don't have to count cel flashes.
Thread Starter
|
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
Heres ignition on - engine off
http://youtube.com/watch?v=txVGdJUr1u8
12.59 Is with ignition off, when the ignition is on, the "pulses" are the 11.x volts. Light off, or no pulse is .03-.05
This is Ignition On - Engine On
http://youtube.com/watch?v=5YOLTY9t0fk
Basically the same as before, except 12.43 is with the ignition off, .03-.05 is when the ignition is turned on and the engine is started, and 13.x is when the "light" would be on. The voltage was a little weird at first, reading -1.x, so I would wait in the video until the meter starts reading .03
EDIT: Forgot to mention, water temp was aprox 175*F at the fill side of the radiator for the engine running check.
http://youtube.com/watch?v=txVGdJUr1u8
12.59 Is with ignition off, when the ignition is on, the "pulses" are the 11.x volts. Light off, or no pulse is .03-.05
This is Ignition On - Engine On
http://youtube.com/watch?v=5YOLTY9t0fk
Basically the same as before, except 12.43 is with the ignition off, .03-.05 is when the ignition is turned on and the engine is started, and 13.x is when the "light" would be on. The voltage was a little weird at first, reading -1.x, so I would wait in the video until the meter starts reading .03
EDIT: Forgot to mention, water temp was aprox 175*F at the fill side of the radiator for the engine running check.
Last edited by Lead Head; Jul 26, 2007 at 04:59 PM.
Thread Starter
|
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
Alright, so with engine running and fully warmed up, I get 41 and 77.
77 Is still because I didn't WOT it, How long do I have to keep it WOT to stop it from reading that? Or should I just ignore it?
41 Is still the heated oxygen sensor/ running to lean. Where is this sensor located on the truck? Can it be cleaned, or does it have to be replaced?
With KOEO, it looks like its just continuous 11, which is good, correct?
77 Is still because I didn't WOT it, How long do I have to keep it WOT to stop it from reading that? Or should I just ignore it?
41 Is still the heated oxygen sensor/ running to lean. Where is this sensor located on the truck? Can it be cleaned, or does it have to be replaced?
With KOEO, it looks like its just continuous 11, which is good, correct?
Thread Starter
|
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
Originally Posted by wtroger
The oxygen sensor is screwed into the exhaust manifold near where the exhaust pipe bolts on it will have 3 wires attached to it. Some have two one on each side the code will usually tell you which one.
Trending Topics
Cargo Master
Joined: May 2001
Posts: 3,208
Likes: 13
Right you don't fix these. I would also check for a vacuum leak it can cause a lean condition and cause rough running.
Last edited by wtroger; Jul 26, 2007 at 09:27 PM.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote