yo David;
I may have to roll soon, so here is what I have in my Site @ notes;
If I have to log-out quickly & can't finish the list; go to my site and use the Search function for the remaiing Codes.
DTC 112 to 114, Intake Air charge temperature sensor (ACT or IAT)Troubleshooting & Possible Causes; "...Codes 112 to 114 will set a IAT sensor code in the EEC, remove and inspect the sensor it could get contaminated by engine oil , K&N oil or dust. Clean the sensor with isopropyl alcohol. If the sensor still fails replace the unit..." Intake Air Temp (IAT); (Air Charge Temperature [ACT] prior to 1992)
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DTC 116 to 118 ECT Troubleshooting & Possible Causes; "...The ECT sensor is a thermistor, basically a resistor that changes voltage accordingly to temperature changes. It provides a reading that's used by the EEC to change fuel delivery at engine startup to reduce emissions and monitors the temperature of the engine. If you see some rust in it clean it by sanding the surface using a fine grit sandpaper, Also check the connector and wiring..."
"This measures the temperature of engine, and has a great impact on fuel ratio. This makes simple work of enriching the mixture on start up, overheating, and full throttle fun. It also allows us to lean out the mixture at certain times, to shorten the time it takes to warm up the engine helping us get great fuel economy. The Engine Coolant Temperature (ECT) sensor is a thermal transistor, which means it allows less electricity to pass through the sensor the warmer it gets. The ECT receives the “Signal Return” voltage from the EEC, then allows a certain amount to return back to the EEC. Because the ECT is in direct contact with the engine coolant flow it changes resistance in response to the temperature of that coolant. The ECT is third in command in the hierarchy of EFI sensors, this means this sensor is very important when calculating fuel ratios and timing curves. This is because of simply chemistry; fuel and spark are constants in the equation. Air is the biggest variable in combustion; it changes density greatly over a range of temperature. So keeping track of the changing temperatures of the incoming air and the engine in which it is burnt becomes very important. But due to its simplicity of design, the ECT is rarely at fault when problems occur. The engine temperature must be greater than 50°F (10°C) to pass the KOEO Self-Test and greater than 180°F (82°C) to pass the KOER Self-Test. To accomplish this, the engine should be at normal operating temperature...Before you start blaming the engine coolant temperature sensor and replacing it make sure the rest of the coolant system is in good condition. All of the following items will affect the ECT: *Coolant level *Radiator Fan *Water Pump *Water Pump and Fan Belts *Thermostat *Base Timing *Engines general condition *Harness and wire general condition..."
Source: by Ryan M (Fireguy50) at fordfuelinjection.com
TESTING
http://fordfuelinjection.com/index.php?p=28
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DTC 121, 122, 123, 124, 125 & DTC P0122, P0123 & P1121 in TSB 94-26-4; "...The following is a list of vehicle symptoms which have been associated with the TPS, but can also be related to other vehicle components. Check engine light, Stalls, quits, hesitation/stumble, fast idle; To minimize the replacement of good components, be advised that the following non-EEC areas may be the issue: Excessive blow-by, PCV malfunction, Vacuum leaks, Fuel pressure, Throttle sticking or linkage binding. MANY VOLTMETERS WILL AUTOMATICALLY CHANGE RANGES WHEN MEASURING TPS OUTPUT FROM IDLE TO WOT. WHEN A VOLTMETER IS USED TO MEASURE TPS OUTPUT FROM IDLE TO WOT, THE METER SCALES OR CHANGES RANGES AUTOMATICALLY. THERE MAY BE AN ERRONEOUS METER DISPLAY UNTIL THE VOLTMETER HAS LOCKED TO THE APPROPRIATE VOLTAGE READING. THE ERRONEOUS METER DISPLAY DOES NOT REPRESENT A DEFECTIVE TPS. NOTE: IT IS RECOMMENDED THAT THE "RANGE LOCK" FEATURE ON MANY METERS BE SET FOR CHECKING TPS VOLTAGE..."
Source: by Ford via miesk5 at
http://home.comcast.net/~miesk5/technical_service_bulletins.htm#technical_service_bulletins.htm
DTC 122 through 125 Troubleshooting & Possible Causes; "...The TPS is located at the end of the throttle shaft on the throttle body. Using the TPS voltage signal the EEC determines fuel delivery based on throttle position. A bad TPS can be the cause of bad idle, which is caused by the injector pulse fluctuating. Some loss in performance can also be expected..."
Test, Operational Description & Parameters
Source: by Ryan M (Fireguy50) at
http://fordfuelinjection.com/index.php?p=30
Testing, Chapter 12, from Ford Fuel Injection and Electronic Engine Control: How to Understand, Service and Modify, 1988-1993
Source: by Charles O. Probst
http://www.yunost.ru/docs/Ford-injectors-book/Part12/Part12-1/Part12-1.pdf
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DTC 126-129, P0235-P0237; "...On gasoline engines, the manifold absolute pressure (MAP) sensor senses atmospheric pressure to produce an electrical signal. The frequency of this signal varies with intake manifold pressure. The powertrain control module monitors this signal to determine altitude. The PCM then adjusts the E4OD shift schedule and EPC pressure for altitude. On diesel engines, the MAP sensor measures boost pressure. The PCM monitors this signal and adjusts EPC pressure. Symptoms: Firm shift feel, late shifts at altitude..."
Source: by Ford via Steve83 (Steve, That dirty old truck) at
http://www.supermotors.net/registry/media/704885
Testing, Symptoms & Overview; "...a multimeter that can read frequency is normally required to check the sensor’s output. But you can also use an ordinary tachometer because a tach can display a frequency signal. Here’s the procedure: Connect the two jumper cables the same as before, (see diagram in site) attaching each end terminal on the sensor to its respective wire in the wiring connector. If you want to measure engine vacuum so you can correlate it to a specific frequency reading, connect a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose. Turn the ignition ON and note the initial reading. The reading on the tachometer should be about 454 to 464 at sea level, which corresponds to a frequency output of 152 to 155 Hz. Start the engine and check the reading again. If the MAP sensor is functioning properly, the reading should drop to about 290 to 330 on the tachometer, which corresponds to a frequency output of about 93 to 98 Hz. No change would indicate a defective sensor or leaky or plugged vacuum hose..." a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose.
Source: by wellsmfgcorp.com
http://www.wellsmfgcorp.com/pdf/Counterpoint1_1.pdf
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DTC 328, 327 or 337 Troubleshooting; Continuous Memory DTC 328 or 327 indicates the EGR valve was closed further than normal or EVP sensor or circuit has failed with an intermittent low voltage sometime during vehicle operation. Continuous Memory DTC 337 indicates the EVP signal to the Powertrain Control Module (PCM) was above the maximum Self-Test limit sometime during vehicle operation. Possible causes: Poor continuity in EVP harness or connectors. Intermittent open or short in EVP sensor or harness. Damaged EVP sensor..." READ MORE
Source: by SigEpBlue (Steve) at
http://www.fullsizebronco.com/forum/archive/index.php/t-160199.html
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556 (O,M) Fuel pump relay primary circuit fault in a 90 4.9 F 150; "...You will need to trouble shoot the circuit to see if it is a EEC or FP relay, the inertia switch or corroded wiring, relay sockets, etc. The fuel pressure should be in the 45-60 psi range.Fuel Pressure Regulator (FPR) Delay TSB 93-22-14 for 90-93 4.9L (Cold Start & Idle Stall)..." READ MORE
Source: by miesk5 at
http://broncozone.com/topic/20822-fuel-pump-maybe-49l-fuel-injection-1990/
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DTC 67 & DTC 634; Manual Lever Position/Transmission Range (MLP/TR) Sensor Pin-Point Test in 92-96; from Ford EVTM; "...Check the resistance of the MLPS: The resistance of the MLPS (pins 30 and 46).." read more
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TOT sensor circuit above maximum voltage possible causes: Damaged TOT sensor. Open harness circuit(s). Damaged processor. or the transmission was overheated. The transmission fluid temperature sensor is located on the solenoid body assembly in the transmission sump. It is a temperature-sensitive device called a thermistor. The resistance value of the transmission fluid temperature sensor will vary with temperature change. The powertrain control module monitors voltage across the transmission fluid temperature sensor to determine the temperature of the transmission fluid. The powertrain control module uses this signal to determine whether a cold start shift schedule is necessary. The cold start shift schedule lowers shift speeds to allow for the reduced performance of cold engine operation. The powertrain control module also uses the transmission fluid temperature sensor input to adjust electronic pressure control pressure for temperature effects and inhibit torque converter clutch operation during the warm-up period. Symptoms: Torque converter clutch and stabilized shift schedule happens too soon after a cold start. Codes P1783 or 657 indicate transmission fluid temperature exceeds 132°C (270° F), results in increased EPC pressure and torque converter clutch engagement. May flash transmission control indicator lamp. Diagnostic Trouble Codes: 636, 637, 638, 657, P0712, P0713, P1711, P1783.
Source: by Ford at
http://www.fullsizebronco.com/forum/showthread.php?p=2452835
Consider Ford Fuel Injection and Electronic Engine Control: How to Understand, Service and Modify, 1988-1993; & Ford Fuel Injection and Electronic Engine Control: How to Understand, Service, and Modify All Ford-Lincoln-Mercury Cars and Light Trucks, 1980 to 1987 by Charlie Probst
Available at Barnes & Noble, E bay, AMAZON, etc.
