Finally learned how to read codes
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The codes are for missing or non functional emissions control equipment. If you need to pass emissions testing, you have some work ahead of you. If there is no emissions testing in your area, your workload just got smaller.
None of the codes are likely to cause an engine to miss or sputter.
Removing the emissions equipment on 5.0 Mustangs does not make them faster. It just makes the computer angry and spit codes, some of which make the computer run in Limp mode with reduced power and economy.
CODE: 31 (KOEO) - EVP circuit below minimum voltage. Vref (5 volt reference voltage supplied by the computer) missing or broken wire, bad connection in circuit, sensor removed or not connected. Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or MAP sensor located on the firewall near the center of the car. Use the black/white wire for the ground for the DVM.
With the sensor removed from the EGR and still connected, press the plunger and watch the voltage change on the brown/lt green wire. Pull the passenger side kick panel and measure the voltage at the computer. You will need to remove the plastic cover over the wires and probe them from the backside. A safety pin may prove very useful for this task. Use pin 27, EVR input (brown/lt green wire) and pin 46, signal ground (black/white wire) to measure the voltage. The orange/white wire is Vref and should always be 5 volts -/+ .25 volt. Be sure to measure Vref at the EGR sensor to rule out any broken wires or bad connections.
Measuring the voltage at the computer helps you spot broken wiring and intermittent connections.
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 computer wants to make sure the A/C is off due to the added load on the engine for the engine running tests. It also
checks to see that the transmission is in Neutral or 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 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.
IF YOU JUMPER THE WIRING TO BYPASS THE NSS, BE SURE TO REMOVE IT PRIOR TO DRIVING THE CAR!!! YOU COULD END UP CRASHING AND BURNING!!!
Code 81 – Secondary Air Injection Diverter Solenoid failure AM2. The solenoid valve located on the back side of the passenger side wheel well is not functional. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Lt Green/Black wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the LT Green/Black wire for the solenoid valve.
With the with the ignition on, look for 12 volts on the red wire on the solenoid connector. No 12 volts and you have wiring problems.
With the engine running, stick a safety pin in the LT Green/Black wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the cats. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
Putting the computer into self test mode will cause the solenoid valve to toggle. If you listen carefully, you may hear it change states.
If you have catalytic converters, you need to fix this code. If not you can use a TAB and TAD eliminator.
Code 82 – Secondary Air Injection Diverter Solenoid failure AM1. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Red/White wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the Red/White wire for the solenoid valve
With the engine running, stick a safety pin in the Red/White wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the heads. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
If you have catalytic converters, you need to fix this code. If not you can use a TAB and TAD eliminator.
Both 81 & 82 codes usually mean that some uneducated person removed the solenoid control valves for the Thermactor Air system in an attempt to make the car faster. It doesn't work that way: no working control valves can cause the cat converters to choke and clog.
Code 84 EGR Vacuum Regulator failure – Broken vacuum lines, no +12 volts, regulator coil open circuit. The EVR regulates vacuum to the EGR valve to maintain the correct amount of vacuum. The solenoid coil should measure 20-70 Ohms resistance. The regulator has a vacuum feed on the bottom which draws from the intake manifold. The other vacuum line is regulated vacuum going to the EGR valve. One side of the EVR electrical circuit is +12 volts anytime the ignition switch is in the run position. The other side of the electrical circuit is the ground path and is controlled by the computer. The computer switches the ground on and off to control the regulator solenoid.
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.
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?
Purge valve solenoid:
Carbon Canister:
If you do not have catalytic converters, say so and I can show you how to get rid of the 81 & 82 codes for just a few dolllars.
None of the codes are likely to cause an engine to miss or sputter.
Removing the emissions equipment on 5.0 Mustangs does not make them faster. It just makes the computer angry and spit codes, some of which make the computer run in Limp mode with reduced power and economy.
CODE: 31 (KOEO) - EVP circuit below minimum voltage. Vref (5 volt reference voltage supplied by the computer) missing or broken wire, bad connection in circuit, sensor removed or not connected. Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or MAP sensor located on the firewall near the center of the car. Use the black/white wire for the ground for the DVM.
With the sensor removed from the EGR and still connected, press the plunger and watch the voltage change on the brown/lt green wire. Pull the passenger side kick panel and measure the voltage at the computer. You will need to remove the plastic cover over the wires and probe them from the backside. A safety pin may prove very useful for this task. Use pin 27, EVR input (brown/lt green wire) and pin 46, signal ground (black/white wire) to measure the voltage. The orange/white wire is Vref and should always be 5 volts -/+ .25 volt. Be sure to measure Vref at the EGR sensor to rule out any broken wires or bad connections.
Measuring the voltage at the computer helps you spot broken wiring and intermittent connections.
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 computer wants to make sure the A/C is off due to the added load on the engine for the engine running tests. It also
checks to see that the transmission is in Neutral or 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 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.
IF YOU JUMPER THE WIRING TO BYPASS THE NSS, BE SURE TO REMOVE IT PRIOR TO DRIVING THE CAR!!! YOU COULD END UP CRASHING AND BURNING!!!
Code 81 – Secondary Air Injection Diverter Solenoid failure AM2. The solenoid valve located on the back side of the passenger side wheel well is not functional. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Lt Green/Black wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the LT Green/Black wire for the solenoid valve.
With the with the ignition on, look for 12 volts on the red wire on the solenoid connector. No 12 volts and you have wiring problems.
With the engine running, stick a safety pin in the LT Green/Black wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the cats. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
Putting the computer into self test mode will cause the solenoid valve to toggle. If you listen carefully, you may hear it change states.
If you have catalytic converters, you need to fix this code. If not you can use a TAB and TAD eliminator.
Code 82 – Secondary Air Injection Diverter Solenoid failure AM1. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Red/White wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the Red/White wire for the solenoid valve
With the engine running, stick a safety pin in the Red/White wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the heads. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
If you have catalytic converters, you need to fix this code. If not you can use a TAB and TAD eliminator.
Both 81 & 82 codes usually mean that some uneducated person removed the solenoid control valves for the Thermactor Air system in an attempt to make the car faster. It doesn't work that way: no working control valves can cause the cat converters to choke and clog.
Code 84 EGR Vacuum Regulator failure – Broken vacuum lines, no +12 volts, regulator coil open circuit. The EVR regulates vacuum to the EGR valve to maintain the correct amount of vacuum. The solenoid coil should measure 20-70 Ohms resistance. The regulator has a vacuum feed on the bottom which draws from the intake manifold. The other vacuum line is regulated vacuum going to the EGR valve. One side of the EVR electrical circuit is +12 volts anytime the ignition switch is in the run position. The other side of the electrical circuit is the ground path and is controlled by the computer. The computer switches the ground on and off to control the regulator solenoid.
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.
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?
Purge valve solenoid:
Carbon Canister:
If you do not have catalytic converters, say so and I can show you how to get rid of the 81 & 82 codes for just a few dolllars.
WOW!! thats alot of stuff, but no, there are no emission standards here. So i have no cats or anything, i have no smog pump, no tube that runs on the back of the heads for the tubing or any egr stuff on the passenger side fenderwell, also i the only egr thing i have is the one on the throttle body which is plugged in electronically but not by vaccuum, wats the next step my good friend?
TAB & TAD solenoid valve eliminators – eliminate codes 81 & 82.
You will still get 44 & 94 codes because the computer looks for a change in the amount of oxygen by checking the O2 sensors when the solenoids are actuated. Actuating the solenoids provides more oxygen in the exhaust, changing the O2 sensor output. No change and you get the 44 & 94 codes.
Don’t do this if you have a catalytic converter H pipe. The catalytic converters must have the air from the smog pump or they will clog up and choke.
See US - Electronic Components Distributor | Newark.com for the resistors to replace the TAB & TAD solenoids
http://www.newark.com/jsp/Passives/Wirewound/OHMITE/43F82RE/displayProduct.jsp?sku=64K8974
If the link fails do a search using the part number
82 ohm, 3 watt wirewound resistor, 94 cents each.
Newark P/N 64K8974
Ohmite part # 43F82RE.
Or use the following part number if the first part number isn't available:
OHMITE|23J82RE|Wirewound Resistor - Vitreous | Newark.com
Newark P/N 64K8241
Ohmite part #23J82RE
Pay a visit to your local Radio Shack to get some heat shrink and some crimp on tap terminals. They do not stock the resistors. Or you can use the Ford connector pin kit from AutoZone.
18 gauge crimp on taps Catalog #: 64-3053
Put the resistor inside the heat shrink tubing and crimp the connectors on. I would choose the Ford pin connectors since they should plug in the TAB & TAD wiring. That way you haven't modified the wiring so it is easy to re-install the TAB & TAD solenoids if emissions testing comes to your area.
Two flat pin connectors.
One 82 ohm, 3 watt resistor.
One piece 3/8" heat sink tubing 2" long.
Two pieces 3/16" heat shrink tubing 1 1/2" long.
Solder the pins onto the resistor leads using electrical solder.
Slide the 3/8" heat shrink tubing over the resistor.
Slide the two pieces of 3/16" heat shrink tubing over the two wires, leaving the flat part of the pins uncovered.
It helps to have the resistor leads straight and not bent as shown in the first picture when you apply heat to the heat shrink tubing. That way, the tubing shrinks more evenly.
Finally, apply heat to shrink all the tubing uniformly.
Bend the leads to fit the spacing on the female TAB & TAD connector sockets.
Push the connector pins of the completed resistor assembly into the empty female TAD or TAD connector sockets on the wiring harness. The resistor assemblies replace the missing solenoids: one resistor assembly per solenoid socket.
Do not crimp on the pins and wrap the mess with electrical tape and say you got the idea from me. If you do, and I hear of it, I will say unkind things about your intelligence and family heritage. Do Quality Work!
This information is for informational purposes only and is intended for use only on off road vehicles. It should not be used on any vehicle operated on public roads.
Operating a vehicle modified in such a manner on public roads is a violation of the EPA codes regarding modification of emission controlled vehicles.
A similar trick can be done to eliminate the 84 & 85 codes.
You will still get 44 & 94 codes because the computer looks for a change in the amount of oxygen by checking the O2 sensors when the solenoids are actuated. Actuating the solenoids provides more oxygen in the exhaust, changing the O2 sensor output. No change and you get the 44 & 94 codes.
Don’t do this if you have a catalytic converter H pipe. The catalytic converters must have the air from the smog pump or they will clog up and choke.
See US - Electronic Components Distributor | Newark.com for the resistors to replace the TAB & TAD solenoids
http://www.newark.com/jsp/Passives/Wirewound/OHMITE/43F82RE/displayProduct.jsp?sku=64K8974
If the link fails do a search using the part number
82 ohm, 3 watt wirewound resistor, 94 cents each.
Newark P/N 64K8974
Ohmite part # 43F82RE.
Or use the following part number if the first part number isn't available:
OHMITE|23J82RE|Wirewound Resistor - Vitreous | Newark.com
Newark P/N 64K8241
Ohmite part #23J82RE
Pay a visit to your local Radio Shack to get some heat shrink and some crimp on tap terminals. They do not stock the resistors. Or you can use the Ford connector pin kit from AutoZone.
18 gauge crimp on taps Catalog #: 64-3053
Put the resistor inside the heat shrink tubing and crimp the connectors on. I would choose the Ford pin connectors since they should plug in the TAB & TAD wiring. That way you haven't modified the wiring so it is easy to re-install the TAB & TAD solenoids if emissions testing comes to your area.
Two flat pin connectors.
One 82 ohm, 3 watt resistor.
One piece 3/8" heat sink tubing 2" long.
Two pieces 3/16" heat shrink tubing 1 1/2" long.
Solder the pins onto the resistor leads using electrical solder.
Slide the 3/8" heat shrink tubing over the resistor.
Slide the two pieces of 3/16" heat shrink tubing over the two wires, leaving the flat part of the pins uncovered.
It helps to have the resistor leads straight and not bent as shown in the first picture when you apply heat to the heat shrink tubing. That way, the tubing shrinks more evenly.
Finally, apply heat to shrink all the tubing uniformly.
Bend the leads to fit the spacing on the female TAB & TAD connector sockets.
Push the connector pins of the completed resistor assembly into the empty female TAD or TAD connector sockets on the wiring harness. The resistor assemblies replace the missing solenoids: one resistor assembly per solenoid socket.
Do not crimp on the pins and wrap the mess with electrical tape and say you got the idea from me. If you do, and I hear of it, I will say unkind things about your intelligence and family heritage. Do Quality Work!
This information is for informational purposes only and is intended for use only on off road vehicles. It should not be used on any vehicle operated on public roads.
Operating a vehicle modified in such a manner on public roads is a violation of the EPA codes regarding modification of emission controlled vehicles.
A similar trick can be done to eliminate the 84 & 85 codes.
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