PCM Data Displays
DESCRIPTIONThe Powertrain Control Module (PCM) Data selection allows viewing of inputs the PCM uses to control powertrain functions. Each data parameter is displayed on the Driver Information Center (DIC) in appropriate units. The values displayed are non-fail safe.
PD01 TPS
Throttle Position Sensor. Display shows degrees of throttle opening from -13.9 to 93.4.
PD02 Manifold Absolute Pressure Sensor
Display shows manifold pressure in Kilo Pascals (kPa) from 10 to 105. At key "ON" (engine not running), the Manifold Absolute Pressure (MAP) value will reflect barometric pressure. Multiply your local barometric pressure by 3.386 to obtain a MAP value that should be within 2 kPa of the displayed value at key "ON." At key "ON," MAP will vary with altitude.
PD03 Barometric Pressure
Display shows the Barometric Pressure (BARO) in kPa from 61 to 103. The BARO reading is taken at key "ON" and is corrected at Wide Open Throttle (WOT). Multiply your local barometric pressure by 3.386 to obtain a BARO value that should be within 2 kPa of the displayed value. BARO varies with altitude (e.g. a typical value in Denver is 85 kPa while a typical value at sea level is 100kPa).
PD04 Engine Coolant Temperature
Engine Coolant Temperature (ECT) sensor. Display shows the temperature of engine coolant in degrees Celsius from -40 to 151.
PD05 Intake Air Temperature Sensor
Intake Air Temperature (IAT) sensor. Display shows the temperature of intake manifold air in degrees Celsius from -40 to 151.
PD07 EGR Pintle Position
Display shows the position of Exhaust Gas Recirculation (EGR) pintle in counts from 0 to 255 based on feedback the PCM receives from the EGR valve.
PD08 Spark Advance
Display shows timing advance in degrees Before Top Dead Center (BTDC) as generated by the ignition control signal from the PCM from -20 to 70 degrees.
PD09 Ignition Ground Voltage
Display shows the voltage difference between CKT 453 (ignition ground) and PCM ground shifted 2.5 volts. A reading of 2.500 volts means the ignition and PCM grounds are at the same voltage. A reading of 1.000 means the ignition ground voltage is 1.5 volts lower than the PCM ground and a reading of 3.500 means the ignition ground voltage is 1.0 volt above the PCM ground. Display shows ignition ground voltage level from 0.003 to 4.970 volts.
PD10 Fuel Pump Feedback Voltage
Battery Voltage. Display shows battery voltage measured at the fuel pump feedback, CKT 120, from 0 to 25.5.
PD11 Engine Speed - RPM
Engine Speed. Display shows crankshaft rotation speed in revolutions per minute (rpm) from 0 to 6375.
PD12 Vehicle Speed
Display shows vehicle speed in miles per hour (mph) from 0 to 255.
PD13 Pintle Position (Rescaled)
Display shows the position of EGR pintle in percent of potential pintle travel from 0 to 100 based on feedback the PCM receives from the EGR valve.
PD15 Ignition 1 Voltage
Display shows ignition voltage measured on CKT 539, PCM pin "2D5," from 0 to 25.5 volts.
PD16 PCM Output Fault Status A
The PCM contains chips, called quad drivers, that provide four switchable ground outputs for running solenoids, relays, telltales and the like. Each of these chips has a fault line that feeds back to the PCM's microprocessor. Each quad driver watches its four output lines. When the output is "OFF," it should see the 12 volts fed to the solenoid, relay coil, or telltale on its output and when the output is "ON," it should see 0 volt since it is grounding the output. If it sees 0 volt when its output is "OFF" or 12 volts when its output is "ON," it pushes the fault line high.
PCM Output Fault Status A shows the states of fault lines from four of the PCM's quad drivers. Each quad driver corresponds to one digit of the display and each digit can only appear as 0 or 1. A "0" means that no output faults are present. A "1" means that a fault is present on at least one output of that quad driver. The chart below identifies the quad drivers corresponding to each digit and what is driven by that driver:
Quad Driver Outputs Driven
A (1st digit) TCC solenoid and engine temperature light *
B (2nd digit) PASS-Key Starter Inhibit Output, and EVAP Solenoid.
C (3rd digit) Cooling Fan Relays and "Service Engine Soon" Malfunction Indicator Lamp (MIL)
D (4th digit) A/C clutch relay, Traction Control System (TCS) delivered torque and Road Sensing Suspension (RSS) Lift/Dive outputs
* 1st digit will be "1" with brake "ON."
PD17 PCM Output Fault Status B
The PCM contains chips, called quad drivers that provide four switchable ground outputs for running solenoids, relays, telltales and the like. Each of these chips has a fault line that feeds back to the PCM's microprocessor. Each quad driver watches its four output lines. When the output is "OFF," it should see the 12 volts fed to the solenoid, relay coil, or telltale on its output and when the output is "ON," it should see 0 volt since it is grounding the output. If it sees 0 volt when its output is "OFF" or 12 volts when its output is "ON," it pushes the fault line high. Other PCM outputs use individual transistors to drive things like injectors or the generator enable. The PCM can monitor these circuits to check for faults the same as the quad drivers do.
PCM Output Fault Status B shows the states of fault lines from one PCM quad driver the eight injector drivers and the generator enable circuit. Each quad driver corresponds to one digit of the display and each digit can only appear as "0" or "1." A "0" means that no output faults are present. A "1" means that a fault is present on at least one output of that quad driver. The chart below identifies the quad drivers corresponding to each digit and what is driven by that driver:
Quad Driver Outputs Driven
E (1st digit) Transaxle Shift Solenoids "A" and "B"
F (2nd digit) Fuel Injectors
G (3rd digit) Generator "L" terminal output *
H (4th digit) Not Used
* 3rd digit will read "1" at key "ON," engine not running.
PD30 Front Bank Injector Pulse Width
Display shows injector pulse width for cylinders 2, 4, 6, and 8 in milliseconds (ms) from 0 to 99.6.
PD31 Rear Bank Injector Pulse Width
Display shows injector pulse width for cylinders 1, 3, 5, and 7 in milliseconds (ms) from 0 to 99.6.
PD32 Front Oxygen Sensor Voltage
Display shows Front Oxygen Sensor (O2S) voltage from 0 to 1.16.
PD33 Rear Oxygen Sensor Voltage
Display shows Rear Oxygen Sensor (O2S) voltage from 0 to 1.16.
PD34 Front Oxygen Sensor Cross Counts
Display shows counts from 0 to 255. The cross count is the number of times the voltage crosses the reference voltage of 0.45 volt in one second.
PD35 Rear Oxygen Sensor Cross Counts
Display shows counts from 0 to 255. The cross count is the number of times the voltage crosses the reference voltage of 0.45 volt in one second.
PD36 Front Short Term Fuel Trim
Display shows counts from 0 to 255. The normal count position for Short Term Fuel Trim is 128. A count greater than 128 indicates that time is being added to the injector pulse width, increasing the amount of fuel to the engine to compensate for a lean condition sensed by the front O2S. A count less than 128 indicates time is being subtracted from the injector pulse width reducing the amount of fuel to the engine to compensate for a rich condition sensed at the front O2S.
PD37 Rear Short Term Fuel Trim
Display shows counts from 0 to 255. The normal count position for Short Term Fuel Trim is 128. A count greater than 128 indicates that time is being added to the injector pulse width, increasing the amount of fuel to the engine to compensate for a lean condition sensed by the Front O2S. A count less than 128 indicates time is being subtracted from the injector pulse width reducing the amount of fuel to the engine to compensate for a rich condition sensed at the front O2S.
PD38 Front Long Term Fuel Trim
Display shows counts from 0 to 255. The normal count position for long term fuel trim is 128. Long Term Fuel Trim value is based on Short Term Fuel Trim 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, increasing the amount of 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.
PD39 Rear Long Term Fuel Trim
Display shows counts from 0 to 255. The normal count position for Long Term Fuel Trim is 128. Long Term Fuel Trim value is based on Short Term Fuel Trim 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, increasing the amount of 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.
PD40 Knock Sensor Spark Retard
Display shows the amount of spark retard due solely to the knock sensor input in degrees from 0 to 44.8.
PD41 Knock Sensor
Display shows the number of instances of engine detonation detected by the knock sensor in one-eighth of a second from 0 to 255.
PD42 Octane Level of Fuel
Display shows the octane level of the fuel based on recent knock sensor activity. This parameter will only display 0, 87, 90, or 93 indicating the fuel octane calculated by the PCM. A parameter value of 0 indicates the PCM has not had enough time to calculate the octane level. Display will always read 0 for vehicles with LD8 (270 h.p.) engine.
PD69 Cruise Lash
Display shows amount of cruise lash as a percentage of cruise servo travel from 0.0 to 99.9%. Cruise lash is the amount of slack found in the cruise control cable at closed throttle. A normal cruise lash percentage would be 13% to 31%.
PD70 Cruise Control Feedback
Display shows the percentage of servo apply as measured by the servo position sensor with 0 equaling full relaxed (no vacuum) and 99 equaling full apply (full vacuum signal). Servo position may vary due to changing driving conditions.
PD71 Transaxle Pressure Switch
Display shows the selected transmission gear based on input from the transaxle pressure switch in a three digit binary code from 000 to 111. Display will read 111 at key "ON," engine not running.
CODE SELECTED GEAR RANGE
000 ILLEGAL
001 DRIVE 4
010 ILLEGAL
011 DRIVE3
100 REVERSE
101 PARK/NEUTRAL
110 DRIVE1
111 DRIVE2
PD72 Transaxle Input Speed
Display shows the turbine shaft speed in rpm from 0 to 8192.
PD73 Torque Converter Slip Speed
Display shows the amount of slip in rpm between the engine and transaxle input shaft from 0 to 8192.
PD74 TPC Solenoid Current
Transaxle Pressure Control Solenoid Current. Display shows the calculated current output from the PCM to drive the Transaxle Pressure Control Solenoid. This current is calculated by the PCM based on the duty cycle of the signal it is sending out and is displayed in amps from 0 to 4.98.
PD75 Current ER
Transaxle Pressure Control Solenoid Current Error. Display shows the difference between the calculated Transaxle Pressure Control Solenoid current output (PD74) and that measured by the PCM at pin "2C15" across the control solenoid current feedback resistor.
PD76 Transaxle Gear Ratio
Display shows the calculated gear ratio of the transaxle based on transaxle input speed and vehicle speed with the final drive ratio subtracted out. If the gear ratio is ever more than 5% different than the ratio listed below, PCM Code P086 will set:
GEAR RATIO
1st 2.96
2nd 1.63
3rd 1.00
4th 0.68
Reverse 2.13
PD77 Transaxle Oil Temperature
Display shows the Transaxle Oil Temperature in degrees Celsius from -40 to 152.
PD78 Transaxle Shift Adapt
Display shows pounds per square inch (psi) from -128 to +127. This value is the increase (+) or decrease (-) in transaxle line pressure that the PCM is commanding through the transaxle pressure control solenoid during the most recent upshift or downshift. The PCM increases or decreases the line pressure during shifts to control shift feel. A normal value is between -10 psi and +10 psi. A value less than 0 psi means the PCM was lowering transaxle line pressure during the most recent shift to soften the shift. A value greater than 0 psi means the PCM was raising transaxle line pressure during the most recent shift to firm up the shift.
PD79 Transaxle Steady State Adapt
Display shows pounds per square inch (psi) from 0 to +127. This value is the increase in transaxle line pressure that the PCM is commanding through the transaxle pressure control solenoid during steady state (not upshifting or downshifting) conditions. The PCM increases the line pressure to control clutch slippage. A normal value is between 0 psi and 10 psi. A value greater than 0 PSI means the PCM has detected some clutch slippage (not during transaxle shifts) and is raising transaxle line pressure to decrease transaxle clutch slippage.
PD80 Transaxle Garage Shift Adapt
Display shows seconds from -3.000 to +3.000. The PCM increases or decreases the line pressure during garage shifts (shifts from Park or Neutral to Drive or Reverse) to control shift feel. This value is the increase (+) or decrease (-) in garage shift duration (length) that the PCM is trying to achieve by adjusting the transaxle line pressure up or down. A normal value is between -1.0 second and +1.0 second.
PD81 Torque Converter Clutch (TCC) Solenoid Duty Cycle
Display shows the current duty cycle (ON time as a percent of cycle time) of the PCM's TCC solenoid output from 0 to 99.6%.
PD82 Transaxle Shift Time
Display shows the amount of time elapsed between when the transaxle left the previous gear ratio and arrived at the current gear ratio, measured in seconds from 0 to 6.375.
PD83 Non-drive Wheel Speed
Display shows the speed of the rear wheels as sent across the Universal Asynchronous Receiver Transmitter (UART) data link (CKT 800) from the Electronic Brake and Traction Control Module (EBTCM), measured in kph from 2 to 255.
PD84 Brake Booster Vacuum
Display shows vacuum (with respect to atmosphere) level in the brake booster in kPa from -10.65 (positive pressure) to 83.4 (approximately 24.6 inches of vacuum).
PD97 PROM Calibration-Transaxle
PCM Display shows a three digit code that uniquely identifies the program stored in the PROM for transaxle control calibration.
PD98 Ignition Cycles
Display shows counts from 1 to 50. The count increases by 1 with each "ON" to "OFF" cycle. When a trouble code sets, the counter is set to 0. If the trouble code becomes history the counter will increment with each key cycle until another code is set, or until the key has been cycled 50 times at which time the code will be erased.
PD99 PROM Calibration-Engine
PCM Display shows a four digit code that uniquely identifies the program stored in the PROM for the engine control calibration.