The Engine Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.

Alternator Input Signal: The scan tool displays On or Off. The state of the Alternator indicator as commanded by the instrument panel cluster (IPC).

Battery Voltage: The scan tool displays 0-20 Volts. The scan tool displays the voltage as received by the Module or the 72-08 battery voltage message from the body control module (BCM) over class 2 lines.

CPP Switch (If Equipped): This parameter displays the state of the clutch pedal switch circuit input. The scan tool will display APPLIED when the clutch pedal is depressed, and RELEASED when the clutch pedal is released.

Clutch Start Switch (If Equipped): This parameter displays the state of the clutch pedal switch circuit input. The scan tool will display APPLIED when the clutch pedal is depressed, and RELEASED when the clutch pedal is released.

Current Gear: This parameter displays the transmission gear commanded by the control module. The scan tool will display 1 when the control module has commanded first gear regardless of the gear selector position. The scan tool will display up to 6 depending upon which gear is commanded and what transmission is in the vehicle. The scan tool will display 9 if the transmission gear is not known.

5-Volt Reference 1: This parameter displays the voltage measured at the 5-volt reference circuit of the control module. There are 2, 5-volt reference circuits which are independent of each other outside the engine control module (ECM), but are bussed together inside the ECM.

5-Volt Reference 2: This parameter displays the voltage measured at the 5-volt reference circuit of the control module. There are 2, 5-volt reference circuits which are independent of each other outside the ECM, but are bussed together inside the ECM.

GEN L-Terminal Signal Command: The scan tool displays On/Off. The scan tool displays Off until the engine is running, then the ECM supplies the percentage value varies depending on electrical loads.

GEN L-Terminal Signal: This parameter indicates whether the control module is allowing the generator to operate. The control module can disable the generator under certain conditions. The scan tool will indicate YES if the control module is allowing generator operation, while NO indicates that the control module is not allowing generator operation.

Ignition 1 Signal: This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is applied to the control module when the ignition switch is in the ignition 1 position. The scan tool will display a higher value with a higher system voltage, and a lower value with a lower system voltage.

PNP Switch (If Equipped): This parameter indicates the range selection of the automatic transmission as calculated by the control module based on input from the park neutral position (PNP) switch. The scan tool will display, In Gear, Park, or Neutral depending on the PNP switch position.

Reverse Inhibit Solenoid Command: This parameter displays the commanded state of the reverse inhibit solenoid. When the vehicle speed is greater than 5 km/h (3 mph), the solenoid is commanded ON, inhibiting shifts to Reverse. When the vehicle speed is less than 5 km/h (3 mph), the solenoid is commanded OFF, allowing shifts to Reverse. The scan tool will display ON/OFF.

Reverse Inhibit Solenoid Circuit Status: This parameter displays the state of the reverse inhibit solenoid circuit. The scan tool displays OK, Incomplete, Short B+, Short Gnd/Open. The scan tool displays Incomplete until the relay control circuit has been commanded ON.

Starter Relay Circuit Status: This parameter displays the state of the starter relay control circuit. The scan tool displays OK, Incomplete, Short B+, Short Gnd/Open. The scan tool displays Incomplete until the relay control circuit has been commanded ON.

Starter Relay Command: The scan tool displays ON/OFF. The scan tool displays Off until the ignition is placed into the CRANK position, then it reads On.

TCC/Cruise Brake Pedal Switch: This parameter displays the state of the brake pedal as determined by the control module. The control module monitors the pedal switch on the brake pedal for vehicles equipped with an automatic transmission. The control module uses this information to release the torque convertor clutch when the brake pedal is applied. The scan tool will display Applied when the brake pedal is depressed. The scan tool will display Released when the brake pedal is not applied.

TR Sw: This parameter indicates the current state of the gear select switch on the transmission/transaxle as calculated by the control module based on the TR switch. The scan tool status will switch from High to Low as different combinations are met. On the scan tool in Park, the PRNDL would read P and A will be Low, and B and C will be High.