Data Displays
PCM DATA DISPLAYAfter ".7.0" is displayed on the Fuel Data Center (FDC), the PCM Data Display can be initiated by depressing the "LO" button on the Electronic Climate Control (ECC). When the "LO" button has been depressed "E.9.0" will be displayed on the FDC. At this time the "HI" and "LO" buttons can be used to select a specific parameter.
P.0.1 Throttle Position Sensor (TPS). Display shows degrees of throttle opening from - 9 to 90.
P.0.1 is the throttle angle in degrees reported from the TPS. Typical values range from 1.6 to 4.6 at warm idle to approaching 80 at wide open throttle.
P.0.2 Manifold Absolute Pressure (MAP) sensor. Display shows manifold pressure in Kilo Pascals (kPa) from 14 to 108.
P.O.2 is the engine intake pressure or engine vacuum reading and reported by the MAP sensor. Typical values range from 22 - 36 kPa at warm idle to approaching 100 at Wide Open Throttle (WOT).
P.O.3 Barometric Pressure (BARO). Display shows the BARO in kPa from 60 to 102.
NOTICE: The BARO reading is taken at key "ON" and is corrected when the throttle position is above 20 degrees.
P.0.3 is the barometric pressure or atmospheric pressure reading that is calculated from the MAP sensor input to the PCM. Typical values range from 103 - 96 kpa at sea level and decreasing as altitude increases.
P.0.4 Coolant Temperature Sensor (CTS). Display shows the temperature in degrees Celsius from -40 to 151.
PO.4 is the engine coolant temperature reading that is received from a thermistor in the engine coolant stream. Typical values range from 850 - 105°C at warm idle.
P.0.5 Manifold Air Temperature (MAT). Display shows the temperature in degrees Celsius from -40 to 151.
P.O.5 is the Manifold Air Temperature reading that is received from a thermistor in the engine intake air stream. Typical values range from 500 to 100°C at warm idle, depending upon ambient temperature and engine speed.
P.0.6 Spark Advance. Display shows advance in degrees Before Top Dead Center (BTDC) from 0 to 90.
P.0.6 is the spark advance in degrees BTDC that the PCM is commanding through the EST circuit to the HEI module. If the Base Timing is properly set at the distributor to 10 BTDC, a reading from a timing meter or timing light should agree with the advance displayed on the FDC.
P.O.7 Battery Voltage. Display shows volts from 0 to 25.6.
P.O.7 is the battery voltage that is measured by the PCM on the fuel pump feedback circuit.The PCM data parameter and a voltmeter connected to the charging system or battery should agree.
P.0.8 Engine Speed. Display shows speed in Revolutions Per Minute (rpm) from 0 to 6370.
P.O.8 is the engine rpm that is calculated by the PCM from the rate at which distributor reference pulses are received from the HEI by the PCM on the distributor reference input. Multiply the display reading by 10 to get the actual engine rpm. The PCM data parameter and a tachometer connected to the HEI system should agree.
P.0.9 Vehicle Speed. Display shows speed in Miles Per Hour (mph) from 0 to 255.
P.O.9 is the vehicle speed received from the vehicle speed sensor located in the transaxle. The vehicle speed on the IPC and P.O.9 should agree.
P.1.2 Injector Pulse Width. Display shows pulse width in milliseconds (ms) from 0 to 99.6.
P.1.2 is the injector pulse width on time in milliseconds that the PCM is commanding the injectors on.
P.1.4 Oxygen Sensor Voltage. Display shows volts from 0.0 to .99.
P.1.4 is the Oxygen sensor voltage reading that is received from the oxygen sensor in the exhaust manifold. The voltage should vary from less than .3 volts to greater than .6 as the fuel system controls from rich to lean. The oxygen sensor voltage will be about .45 volts when the sensor is cold.
P.1.6 Oxygen Sensor Cross Counts. Display shows counts from 0 to 255.
NOTICE: The cross count is the number of times the voltage crosses the reference voltage of .45 volts in one second.
P.1.6 Oxygen sensor crossover counts, is calculated by the PCM from the number of rich to lean toggles that have occurred within a 1 second period. Cross counts can be used to detect Oxygen sensor activity. The Oxygen sensor has detected more rich/lean toggles as the cross count number increases.
P.1.8 Integrator. Display shows counts from 0 to 255. The normal count position for the Integrator is 128, and indicates that the engine is operating normally. A count greater than 128 indicates that time is being added to the injector pulse width, which adds more fuel to the engine. A count less than 128 indicates time is being subtracted from the injector pulse width reducing the amount of fuel to the engine.
P.2.O Block/Learn (B/L). Display shows counts from 0 to 255. The normal count position for the B/L is 128, and indicates that the engine is operating normally. The B/L value is based on Integrator learned values. It is stored in memory blocks of the long term memory according to MAP and rpm values. A count greater than 128 indicates that time is being added to the injector pulse width, which adds more fuel to the engine. A count less than 128 indicates time is being subtracted from the injector pulse width reducing the amount of fuel to the engine.
P.2.1 Cruise Control Feedback. Display shows the percentage of servo apply with 0 equaling full extend and 99 equaling full retract.
P.2.1 is the percent servo stroke being reported to the PCM from the Servo Position Sensor.
P.2.2 PRNDL switch status. Display shows the status of the PRNDL switch CKTs 773 and 772, which are inputs C and B to the PCM. 0 indicates that the switch is closed and 1 indicates that the switch is open.
P.2.2 and P.2.3 are combine to produce a gray code for the PCM. The gray code is used to determine the gear selection of the transmission.
P.2.3 PRNDL switch status. Display shows the status of the PRNDL switch CKTs 771 and 776, which are inputs A and P to the PCM. 0 indicates that the switch is closed and 1 indicates that the switch is open.
P.2.2 and P.2.3 are combine to produce a gray code for the PCM. The gray code is used to determine the gear selection of the transmission.
P.2.4 Ignition Cycles. Display shows counts from 1 to 50. The count increases by 1 with each key cycled from "ON" to "OFF". The ignition cycle count is reset to 0 each time that power is removed is removed from the PCM and each time the that an PCM trouble code is logged. In normal operation, the counter counts up to 50, then rolls over to 0 and begins to count to 50 again. If a code is set, the ignition counter can be used to see how many ignition cycles have passed since the code was set.
P.2.5 PROM Identification Code. Display shows a three digit code that identifies the PROM.
P.2.5 is a PROM identification code number that is unique to each PCM calibration. The PROM ID is used to verify that the proper PROM has been installed in the PCM and to identify different PROM calibrations without performing a PCM removal and replacement.