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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

engine off codes

  • Thread starter Thread starter 50gt1988
  • Start date Start date Jun 6, 2005

50gt1988

New Member
Dec 25, 2004
154
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Spanaway, WA
Jun 6, 2005
#1
  • Jun 6, 2005
  • #1
I pulled codes with the motor off and I got:
51
22
53
54
35
67
Also I was confused becasue my car is a 1988 GT but I put a computer and wire harness off of a 1992 on my car, but the computer reads in 2 digit codes not 3 digit?
 

stang22

Active Member
Jan 29, 2003
1,318
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38
Washington, D.C.
Jun 6, 2005
#2
  • Jun 6, 2005
  • #2
Nope, 2 digit codes it is. This site has a lot of good info on the EEC and codes.

http://www.troublecodes.net/Ford/

Tim
 

50gt1988

New Member
Dec 25, 2004
154
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0
Spanaway, WA
Jun 6, 2005
#3
  • Jun 6, 2005
  • #3
Yeah I have a book that tells me all of that info but I've read somewere that those codes my car threw are normal for an engine off test? Is this right?
 

stang22

Active Member
Jan 29, 2003
1,318
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38
Washington, D.C.
Jun 6, 2005
#4
  • Jun 6, 2005
  • #4
My car does not pull any codes with the KOEO test. I don't think that is normal. BAP, ECT, TPS, etc, etc...

Does your car start? Have you tried resetting the computer to see if the same codes come back?

Tim
 

50gt1988

New Member
Dec 25, 2004
154
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Spanaway, WA
Jun 6, 2005
#5
  • Jun 6, 2005
  • #5
My car runs fine, it runs a little rich and a little jerky sometimes which is why i bought the code reader. I used to have one but it broke. I haven't tried reseting it.
 

stang22

Active Member
Jan 29, 2003
1,318
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38
Washington, D.C.
Jun 6, 2005
#6
  • Jun 6, 2005
  • #6
I would adjust the TPS ASAP. That might cure some of your studdering. Actually, fix all of those codes. Good luck!

Tim
 

50gt1988

New Member
Dec 25, 2004
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Spanaway, WA
Jun 6, 2005
#7
  • Jun 6, 2005
  • #7
I've heard of adjusting the TPS, how excactly do you do it?
 

stang22

Active Member
Jan 29, 2003
1,318
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38
Washington, D.C.
Jun 6, 2005
#8
  • Jun 6, 2005
  • #8
Man, I have a better link on my computer at work, but this one is a good one. The other just has a lot of pics...

http://www.duggerracing.com/techtips/tps.shtml

http://www.dccurrent.com/fbt/tps.htm


Tim
 

50gt1988

New Member
Dec 25, 2004
154
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0
Spanaway, WA
Jun 6, 2005
#9
  • Jun 6, 2005
  • #9
Wow, that makes since. I recentaly put a new TPS on my car and just screwed it on. Thanks
 

stang22

Active Member
Jan 29, 2003
1,318
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38
Washington, D.C.
Jun 6, 2005
#10
  • Jun 6, 2005
  • #10
50gt1988 said:
Wow, that makes since. I recentaly put a new TPS on my car and just screwed it on. Thanks
Click to expand...
No problem!

Tim
 

jrichker

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#11
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  • #11
Code 22 MAP (vacuum) or BARO signal out of range. The MAP or BARO sensor is pretty much the same sensor for both Mass Air & Speed Density cars. The main difference is where it is connected. Mass Air cars vent it to the atmosphere, while Speed Density cars connect it to the intake manifold vacuum. Its purpose is to help set a baseline for the air/fuel mixture and changes in barometric pressure. The MAP or BAP sensor puts out a 5 volt square wave that changes frequency with variations in atmospheric pressure. The base is 154 HZ at 29.92" of mercury - dry sunny day at sea level, about 68-72 degrees. You need an oscilloscope or frequency meter to measure it.

Baro or MAP test using frequency meter - run the test key on engine off. The noise from the ignition system will likely upset the frequency meter. I used a 10 x oscilloscope probe connected from the frequency meter to the MAP/BAP to reduce the jitter in the meter's readout.

If it is defective, your air/fuel ratio will be off and the car’s performance & emissions will suffer

Code 51 Engine Coolant Temperature (ECT) sensor signal is/was too high - Possible bad ECT sensor, or wiring.
Use Pin 46 on the computer for ground for both ECT & ACT to get most accurate readings.

Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

Voltages may be measured across the ECT by probing the connector from the rear. Use care in doing it so that you don't damage the wiring or connector.

Here's the table :

68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

Code 53 - Throttle Position sensor too high – TPS – TPS out of adjustment, bad connections, missing signal ground, bad sensor.

Here’s a TPS tip I got from NoGo50…

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better. Just don’t go over .99, or you upset the fuel calibration and idle quality will suffer.

(copied from MustangMax, Glendale AZ)
1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.
Check the black/white wire resistance. Connect one ohmmeter lead to the black/white wire on the TPS and one lead to the negative post on the battery. You should see less than .5 ohm, more than that indicates a problem. Always take resistance measurements with the circuit powered off.

Clean the 10 pin salt & pepper shaker connectors.
.

Code 54 – ACT sensor out of range. Broken or damaged wiring, bad ACT sensor. Note that that if the outside air temp is below 50 degrees F that the test for the ACT can be in error.

Check the resistance of the black/white wire to battery ground. If it is less than 1 ohm, it is good. If it is more than 1 ohm, the black/white wire has bad connections or a broken wire. Always take resistance measurements with the circuit powered off.

Then check the resistance of the ACT sender located in the #5 intake runner on most 5.0 stangs.

ACT & ECT test data:

The ACT & ECT have the same thermistor, so the table values are the same

Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

Pin 25 on the computer - ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer. Here's the table :

68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

Code 35 EVR - EVP sensor signal is/was high – Bad sensor, or possible missing ground for EVR circuit. With the power off, measure the resistance between the black wire and battery ground. You should see less than 1 ohm. Check the same black wire on the EGR and MAP sensor. More than 1 ohm there and the wire is probably broken in the harness between the engine and the computer. The 10 pin connectors pass the black wire back to the computer, and can cause problems.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

See http://fordfuelinjection.com/index.php?p=6 for more wiring help & 10 pin connector diagrams


Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On Engine On tests. You can generally ignore this code, since it has no effect on engine performance.

The one thing common to all your codes except the 67 code, is a bad signal ground from the sensors to the computer. Read the code descriptions I posted through carefully and you will find the ground test proceedure to help you isolate and fix the bad sensor signal ground.
 
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