ECM Data Display
ECM DATA DISPLAYS:
When troubleshooting a malfunction, the ECM display can be used to compare the vehicle with problems to a vehicle which is functioning properly. Data displays are operated as follows:
1. Pressing the "OFF" button will stop the test selection process and return the display to the next available test type for the selected system.
2. Pressing the "LO" fan button will display the next smaller test number for the selected test type. If this button is touched with the lowest test number displayed, the highest test number will then appear.
3. Pressing the "HI" fan button will display the next larger test number for the selected test type. If this pad is touched with the highest test number displayed, the lowest test number will then appear.
ED01 The throttle position sensor "TPS" is displayed in millivolt.% (mV) from 0 to 5100.
ED04 The coolant temperature "COOLANT TP" is displayed in degrees (0C) from -40 to 152.
ED05 The manifold air temperature "MAT" also called air temperature sensor is displayed in degrees ('C) from -40 to 152.
ED06 The injector pulse width "MS INJ PW" is displayed in milliseconds (mS), from 0 to 1002.
ED07 The oxygen sensor voltage "OXY SENSOR" is displayed in millivolt from 0 to 1128 mV.
ED08 The spark advance value "DEG SIPARK" is displayed in degrees, from 0 to 70.
ED10 The battery voltage "BATT VOLTS" is read in volts, from 0 to 25.5.
ED11 The engine speed "RPM" is displayed from 20 to 6375.
ED12 The vehicle speed "MPH" is displayed in miles per hour from 0 to 159.
ED16 The knock retard "SPARK ANGLE" is displayed in degrees of timing pulled out, from in 0 to 45.
ED17 The knock sensor activity "OLD PA3" is displayed as counts, an arbitrary number that increases from 0 to 255, according to the amount of activity from the knock sensor.
ED18 The oxygen sensor cross counts "CROSS CTS" is displayed as the number of times the sensor crossed a reference voltage each second.
ED19 The fuel integrator "INT FUEL" is displayed in counts, from 0 to 255.
ED20 The block learn multiplier "BLM FUEL" is displayed in counts, from 0 to 255.
ED21 The mass "AIR FLOW" is displayed in grams per second of air flow from 0 to 255.
ED22 The idle air control "IAC MOTOR" is displayed in steps of travel from 0 to 255.
ED23 The ENGINE LOAD (LV8) is displayed in counts from 0 to 255.
ED98 The ignition cycle counter value "IGN CYCLES" is the number of times the ignition has been cycled to "OFF" since an ECM trouble code was last detected. After 50 ignition cycles without any malfunction being detected, all stored ECM codes are cleared.
ED99 The "PROM ID" is displayed as a number up to four digits long which can be used to identify the MEM-CAL installed in the ECM.
ECM INPUT DISPLAYS:
When troubleshooting a malfunction the ECM input display can be used to determine if the switched inputs can be properly interpreted. When one of the various input tests is selected, the state of that device is displayed as "HI" or "LO". In general, the "HI" and "LO" refer to the input terminal voltage for that circuit. The display also indicates if the input changed state so that the technician could activate or deactivate any listed device and return to the display to see if it changed state. If a change of state occurred, an "X" will appear next to the "HI/LO" indicator. The "X" will only appear once per selected input, although the "HI/LO" indication will continue to change as the input changes. Some tests are momentary and the "X" can be used as an indication of a change. The following is a list of ECM inputs:
EI60 The "EVRV" display is "LO" when the EGR is "ON".
EI74 The "PARK-NEUT" display is "LO" when the vehicle is in park or neutral.
EI78 The power steering pressure switch "POWER STRG" display is "LO" when power steering pressure (effort) is high, engine running and steering wheel in crimp position.
EI82 The fourth gear switch "4TH GEAR" display is "HI" when the vehicle is in fourth gear.
ECM OUTPUT DISPLAYS:
When troubleshooting a malfunction, the ECM output cycling can be used to determine if the output tests can be actuated regardless of the inputs and normal program instructions. Once a test in outputs has been selected, the test will display "HI" and "LO" for three seconds in each state to indicate the command. Actual circuit operation will depend on circuit integrity. If the test selected is not allowed under the current conditions a " =- =- " display will result. A brief summary of each output is provided below:
EOOO The "CYCLE NONE" display will not display "HI" or "LO" as this is a resting spot where no outputs will be cycled.
EO01 The CANISTER PURGE SOLENOID display will be "LO" when the soleniod is "ON" (energized).
EO02 The TORQUE CONVERTER CLUTCH (TCC) display will be "LO" when the TCC is on (energized).
EO04 The EGR SOLENOID display will be "LO" when the EGR solenoid is "ON" (energized).
EO07 The IAC MOTOR set does not cycle "HI"or "LO" but instead extends the pintle all the way out so minimum air adjustment can be made.
EO08 The "A/C CLUTCH" display will be "HI" when the clutch is "ON" (energized).
EO09 The COOLANT FAN RELAY display is "LO" when the coolant fan is "ON" (energized).