Codes Help

Discussion in 'Fox 5.0 Mustang Tech' started by foxbody1989, Nov 17, 2013.


  1. foxbody1989

    foxbody1989 Member

    Joined:
    Mar 17, 2010
    Messages:
    61
    Likes Received:
    0
    Trophy Points:
    7
    Location:
    Tacoma, WA
    Hello everyone I'm running real rich and decided to pull my codes and these are what I got. koeo: 34, 85, and 67. Koer 21, 94, 44, and 34 just looking for some help not sure if I fix a certain one it will fix all or so on.
    #1
  2. foxbody1989

    foxbody1989 Member

    Joined:
    Mar 17, 2010
    Messages:
    61
    Likes Received:
    0
    Trophy Points:
    7
    Location:
    Tacoma, WA
    Could I possibly have bad 02 sensors somewhere in the mix
    #2
  3. 90lxwhite

    90lxwhite Mustang Master

    Joined:
    Aug 25, 2011
    Messages:
    2,178
    Likes Received:
    261
    Trophy Points:
    104
    Location:
    Between the Red and Rio
    #3
  4. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,590
    Likes Received:
    356
    Trophy Points:
    134
    Location:
    Dublin GA
    You posted a TECH question in Talk. This limits your chances of getting some really good advice, since most guys aren't looking for Tech stuff in the Talk forum.

    My advice to you is to twofold:
    1.) Send a PM to one of the moderators and have your thread moved to 5.0 Tech
    2.) Next time you start a thread, think about where it goes. If you are new to Stangnet, please read the terms of service and give extra thought to where your new thread belongs. There is some help in the text below to help you find the best place to start your thread.
    General tech problems go in 5.0 Tech. Tech is for suspension, electrical, brakes, body, engine repair and general troubleshooting on the computer & trouble codes

    Tall tales about your 5.0 Mustang, pictures of your 5.0 Mustang project and stories about your last trip to the race track go in 5.0 Talk.

    Do this and you'll get the best answers quicker and not get lost in the maze of posts about everything but the type of problem you are having.
    @Noobz347 please move this to Tech
    Having said that, here’s some help…

    There are no indications of O2 sensor problem in any of the codes you listed. The O2 sensors set codes 41, 91 or 42, 92 when they are not working correctly.

    Code 34 Or 334 - EGR voltage above closed limit –

    Revised 26-Sep-2011 to add EGR cleaning and movement test for pintle when vacuum is applied to diaphragm

    Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the flange side of the EGR by mouth. If it leaks, there is carbon stuck on the pintle valve seat clean or, replace the EGR valve ($85-$95).

    Recommended procedure for cleaning the EGR:
    Conventional cleaning methods like throttle body cleaner aren’t very effective. The best method is a soak type cleaner used for carburetors. If you are into fixing motorcycles, jet skis, snowmobiles or anything else with a small carburetor, you probably have used the one gallon soak cleaners like Gunk or Berryman. One of the two should be available at your local auto parts store for $22-$29. There is a basket to set the parts in while they are soaking. Soak the metal body in the carb cleaner overnight. Don’t immerse the diaphragm side, since the carb cleaner may damage the diaphragm. If you get any of the carb cleaner on the diaphragm, rinse it off with water immediately. Rinse the part off with water and blow it dry with compressed air. Once it has dried, try blowing through the either hole and it should block the air flow. Do not put parts with water on them or in them in the carb cleaner. If you do, it will weaken the carb cleaner and it won’t clean as effectively.

    Gunk Dip type carb & parts soaker:
    [​IMG]


    If you have a handy vacuum source, apply it to the diaphragm and watch to see if the pintle moves freely. Try blowing air through either side and make sure it flows when the pintle retracts and blocks when the pintle is seated. If it does not, replace the EGR.


    If the blow by test passes, and you have replaced the sensor, then you have electrical ground problems. Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same wire on the TPS. It should be less than 1.5 ohm. Next check the resistance between the black/white wire and the negative battery post. It should be less than 1.5 ohm.

    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.

    Let’s put on our Inspector Gadget propeller head beanies and think about how this works:
    The EGR sensor is a variable resistor with ground on one leg and Vref (5 volts) on the other. Its’ resistance ranges from 4000 to 5500 Ohms measured between Vref & ground, depending on the sensor. The center connection of the variable resistor is the slider that moves in response to the amount of vacuum applied. The slider has some minimum value of resistance greater than 100 ohms so that the computer always sees a voltage present at its’ input. If the value was 0 ohms, there would be no voltage output. Then the computer would not be able to distinguish between a properly functioning sensor and one that had a broken wire or bad connection. The EGR I have in hand reads 700 Ohms between the slider (EPV) and ground (SIG RTN) at rest with no vacuum applied. The EGR valve or sensor may cause the voltage to be above closed limits due to the manufacturing tolerances that cause the EGR sensor to rest at a higher position than it should.

    The following sensors are connected to the white 10 pin connector (salt & pepper engine harness connectors)
    [​IMG]

    This will affect idle quality by diluting the intake air charge


    Code 85 - CANP solenoid - The Carbon Canister solenoid is inoperative or missing. Check vacuum lines for leaks and cracks. Check electrical wiring for loose connections, damaged wiring and insulation. Check solenoid valve operation by grounding the gray/yellow wire to the solenoid and blowing through it.
    The computer provides the ground for the solenoid. The red wire to the solenoid is always energized any time the ignition switch is in the run position.

    Charcoal canister plumbing - one 3/8" tube from the bottom of the upper manifold to the rubber hose. Rubber hose connects to one side of the canister solenoid valve. Other side of the solenoid valve connects to one side of the canister. The other side of the canister connects to a rubber hose that connects to a line that goes all the way back to the gas tank. There is an electrical connector coming from the passenger side injector harness near #1 injector that plugs into the canister solenoid valve. It's purpose is to vent the gas tank. The solenoid valve opens at cruse to provide some extra fuel. The canister is normally mounted on the passenger side frame rail near the smog pump pulley.

    [​IMG]

    It does not weigh but a pound or so and helps richen up the cruse mixture. It draws no HP & keeps the car from smelling like gasoline in a closed garage. So with all these good things and no bad ones, why not hook it up & use it?


    The purge valve solenoid connector is a dangling wire that is near the ECT sensor and oil filler on the passenger side rocker cover. The actual solenoid valve is down next to the carbon canister. There is about 12"-16" of wire that runs parallel to the canister vent hose that comes off the bottom side of the upper intake manifold. That hose connects one port of the solenoid valve; the other port connects to the carbon canister.

    The purge valve solenoid should be available at your local auto parts store.

    Purge valve solenoid:
    [​IMG]


    The carbon canister is normally mounted on the passenger side frame rail near the smog pump pulley.
    Carbon Canister:
    [​IMG]


    Code 67 –
    Revised 2 Nov 2012 to add definition of the NSS functions for both 5 speed and auto transmissions

    Cause of problem:
    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.

    External evidence from other sources claims that a code 67 can cause an idle surge condition. Do try to find and fix any issues with the switch and wiring if you get a code 67.

    What the NSS (Neutral Safety Switch) does:
    5 speed transmission: It has no connection with the starter, and the engine can be cranked without it being connected.
    Auto transmission: It is the safety interlock that prevents the starter from cranking the engine with the transmission in gear.
    What it does for both 5 speed and auto transmission cars:
    The computer wants to make sure the A/C is off due to the added load on the engine for the engine running computer diagnostic tests. It also checks to see that the transmission is in Neutral (5 speed and auto transmission) and the clutch depressed (T5, T56, Tremec 3550 & TKO)). This prevents the diagnostics from being run when the car is driven. Key On Engine Running test mode takes the throttle control away from the driver for several tests. This could prove hazardous if the computer was jumpered into test mode and then driven.

    The following is for 5 speed cars only.
    The NSS code 67 can be bypassed for testing. You will need to temporarily ground computer pin 30 to the chassis. Computer pin 30 uses a Lt blue/yellow wire. Remove the passenger side kick panel and then remove the plastic cover from the computer wiring connector. Use a safety pin to probe the connector from the rear. Jumper the safety pin to the ground near the computer.
    Be sure to remove the jumper BEFORE attempting to drive the car!!!

    [​IMG]

    Code 21 – ECT sensor out of range. Broken or damaged wiring, bad ECT sensor.
    Note that that if the outside air temp is below 50 degrees F that the test for the ECT can be in error. Warm the engine up until you get good hot air from the heater and then dump the codes again.

    The ECT sensor has absolutely nothing to do with the temperature gauge. They are different animals. The ECT sensor is normally located it the passenger side front of the engine in the water feed tubes for the heater.

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

    ACT & ECT test data:

    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

    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.

    [​IMG]

    Voltages may be measured across the ECT/ACT by probing the connector from the rear. A pair of safety pins may be helpful in doing this. Use care in doing it so that you don't damage the wiring or connector.

    Here's the table :

    50 degrees F = 3.52 v
    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
    212 degrees F = .47 v
    230 degrees F = .36 v
    248 degrees F = .28 v

    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
    212 degrees F = 2.07 K ohms
    230 degrees F = 1.55 K ohms
    248 degrees F = 1.18 k ohms

    Diagram courtesy of Tmoss & Stang&2birds

    [​IMG]

    See the following website for some help from Tmoss (diagram designer) & Stang&2Birds
    (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

    Ignition switch wiring
    http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

    Fuel, alternator, A/C and ignition wiring
    http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

    Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
    http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

    Vacuum diagram 89-93 Mustangs
    http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

    Codes 44 & 94 - AIR system inoperative - Air Injection. Check vacuum lines for leaks, & cracks. Check for a clogged air crossover tube, where one or both sides of the tube clog with carbon.

    [​IMG]

    Revised 21 Sep 2012 to correct the description of the process that sets the code and include Thermactor Air System diagram.

    If you have a catalytic converter H pipe, you need to fix these codes. If you don't, then don't worry about them.

    Code 44 RH side air not functioning.
    Code 94 LH side air not functioning.

    The TAD solenoid/TAD diverter valve directs smog pump output to either the crossover tube attached to the cylinder heads or to the catalytic converters.

    The O2 sensors are placed before the catalytic converters, so they do not see the extra O2 when the smog pump's output is directed to the converters or the input just before the converter.

    The 44/94 code uses the O2 sensors to detect a shift in the O2 level in the exhaust. The smog pump provides extra air to the exhaust which raises the O2 level in the exhaust when the smog pump output is directed through the crossover tube.

    When there is an absence of increase in the O2 levels when the TAD solenoid/TAD diverter valve directs air through the crossover tube, it detects the lower O2 level and sets the code.

    Failure mode is usually due to a clogged air crossover tube, where one or both sides of the tube clog with carbon. The air crossover tube mounts on the back of the cylinder heads and supplies air to each of the Thermactor air passages cast into the cylinder heads. When the heads do not get the proper air delivery, they set codes 44 & 94, depending on which passage is clogged. It is possible to get both 44 & 94, which would suggest that the air pump or control valves are not working correctly, or the crossover tube is full of carbon or missing.

    Testing the system:
    Note that the engine must be running to do the tests unless stated otherwise. For safety’s sake, do test preparation like loosening clamps, disconnecting hoses and connecting things to a vacuum source with the engine off.


    Disconnect the big hose from smog pump: with the engine running you should feel air output. Reconnect the smog pump hose & apply vacuum to the first vacuum controlled valve: Its purpose is to either dump the pump's output to the atmosphere or pass it to the next valve.

    The next vacuum controlled valve directs the air to either the cylinder heads when the engine is cold or to the catalytic converter when the engine is warm. Disconnect the big hoses from the back side of the vacuum controlled valve and start the engine. Apply vacuum to the valve and see if the airflow changes from one hose to the next.

    The two electrical controlled vacuum valves mounted on the rear of the passenger side wheel well turn the vacuum on & off under computer control. Check to see that both valves have +12 volts on the red wire. Then ground the white/red wire and the first solenoid should open and pass vacuum. Do the same thing to the light green/black wire on the second solenoid and it should open and pass vacuum.

    Remember that the computer does not source power for any actuator or relay, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.

    The following computer tests are done with the engine not running.
    The computer provides the ground to complete the circuit to power the solenoid valve that turns the
    vacuum on or off. The computer is located under the passenger side kick panel. Remove the kick panel & the cover over the computer wiring connector pins. Check Pin 38 Solenoid valve #1 that provides vacuum to the first Thermactor control valve for a switch from 12-14 volts to 1 volt or less. Do the same with pin 32 solenoid valve #2 that provides vacuum to the second Thermactor control valve. Turning the ignition to Run with the computer jumpered to self test mode will cause all the actuators to toggle on and off. If after doing this and you see no switching of the voltage on and off, you can start testing the wiring for shorts to ground and broken wiring. An Ohm check to ground with the computer connector disconnected & the solenoid valves disconnected should show open circuit between the pin 32 and ground and again on pin 38 and ground. In like manner, there should be less than 1 ohm between pin 32 and solenoid valve #2 and pin 38 & Solenoid valve #1.

    The following computer tests are done with the engine running.
    If after checking the resistance of the wiring & you are sure that there are no wiring faults, start looking at the solenoid valves. If you disconnect them, you can jumper power & ground to them to verify operation with the engine running. Power & ground supplied should turn on the vacuum flow, remove either one and the vacuum should stop flowing.

    Typical resistance of the solenoid valves is in the range of 20-70 Ohms.

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

    http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

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

    If you have a catalytic converter H pipe, you need to fix these codes. If you don't, then don't worry about them
    #4
  5. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

    Joined:
    Jan 5, 1985
    Messages:
    19,890
    Showcase:
    58
    Albums:
    5
    Likes Received:
    2,476
    Trophy Points:
    174
    Location:
    Box behind Walmart
    #5
  6. 90lxwhite

    90lxwhite Mustang Master

    Joined:
    Aug 25, 2011
    Messages:
    2,178
    Likes Received:
    261
    Trophy Points:
    104
    Location:
    Between the Red and Rio
    And the help is pouring in
    #6
  7. liljoe07

    liljoe07 Active Member

    Joined:
    Feb 18, 2009
    Messages:
    1,179
    Likes Received:
    14
    Trophy Points:
    39
    Location:
    Cartersville,Ga
    Code 67 is of no concern. If it was an actual fault, it wouldnt let you run the codes KOER. So dont worry about that one. Code 21 will show up if the engine is cold. If code 21 shows up in the KOEO test, it means the ECT is below 50*. If it shows up in the KOER test, that means its below 160*. So the engine coolant needs to be above 160* for the ECT to not throw a code in the KOER test.

    It would help if you listed what was, if anything, was deleted on the engine. As that would help eliminate what codes could be ignored. And the codes that needed addressed could be focused on.
    #7
  8. 90lxwhite

    90lxwhite Mustang Master

    Joined:
    Aug 25, 2011
    Messages:
    2,178
    Likes Received:
    261
    Trophy Points:
    104
    Location:
    Between the Red and Rio
    You get it sorted out? How's she running? Aren't you glad it was moved to "tech" where there's so much more help?
    #8

Share This Page