Scan Tool Data List
WARNING: This page is about a different car, the 2001 GMC Sierra, 2001 GMC Cab & Chassis Sierra, 2001 Chevrolet Silverado, and 2001 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Use the scan tool data listed in this table for comparison after the On-Board Diagnostic system check and finding the on-board diagnostics function properly with no diagnostic codes displayed.
The Typical Scan Tool Data Values are an average of display values recorded from normally operating vehicles. The Typical Scan Tool Data Values are intended to represent what a normally functioning system would display. The values you get may vary due to a low battery charge or other reasons. But they should be very close.
Do not use a scan tool that displays faulty data. Report the problem to the manufacturer. The use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.
Use only the parameters listed in the tables for diagnosis. If a scan tool reads other parameters, the values are not recommended by General Motors for use in diagnosis. For more description on the values and the use of the scan tool diagnosis the ECM inputs, refer to the applicable diagnosis. If all values are within the range illustrated, refer to Symptoms - Engine Controls .
Scan Tool Data List
| Scan Tool Parameter | Data List | Units Displayed | Typical Data Value |
|---|---|---|---|
| Operating Conditions: Engine Idling/Lower Radiator Hose Hot/Closed Throttle/Park or Neutral/Accessories Off | |||
| 4WD Low Signal | Engine Data 1 | Enabled/Disabled | Disabled |
| 4WD Signal | Engine Data 1 | Enabled/Disabled | Disabled |
| A/C Clutch Feedback Signal | Engine Data 1 | Relay ON/OFF | Relay OFF |
| A/C Relay Command | Engine Data 1 | ON/OFF | Off |
| A/C Request Signal | Engine Data 1 | Yes/No | No |
| A/C Sec. High Press. SW | Engine Data 1 | Open/Closed | Closed |
| Actual Fuel Rail Pressure | Engine Data 1 Engine Data 2 Fuel System |
MPa/PSI | 37-40 MPa (5,200-5,800 PSI) |
| Alternator L Terminal | Engine Data 1 | ON/OFF | OFF |
| APP Indicated Angle | Engine Data 1 Engine Data 2 Fuel System |
% | 0.0 |
| APP Sensor 1 | Engine Data 1 | Volts |
|
| APP Sensor 2 | Engine Data 1 | Volts |
|
| APP Sensor 3 | Engine Data 1 | Volts |
|
| Balancing Rate Cyl. 1-8 | Engine Data 2 | mm3 | -4.0 to +4.0 |
| BARO | Engine Data 1 | kPa | 65-104 (Varies with altitude) |
| Battery Voltage | Engine Data 1 | Volts | 12-14 (Accuracy +/- 0.4 Volts) |
| Boost Pressure Sensor | Engine Data 1 | kPa/PSI | 60-170 kPa (8-24 PSI) (All RPMs) |
| Calculated Fuel Rate | Engine Data 1 Engine Data 2 Fuel System |
mm3 | 7-9 |
| CAM Reference Signal Missed | Engine Data 1 | Counts | 0 |
| Check Trans Lamp | Engine Data 1 | ON/OFF | OFF |
| Clutch Pedal Switch | Engine Data 1 | Applied/Released | Released |
| Cruise Control Active | Engine Data 1 | Yes/No | No |
| Cruise ON/OFF Switch | Engine Data 1 | ON/OFF | OFF |
| Cruise/Resume/Accel Switch | Engine Data 1 | ON/OFF | OFF |
| Cruise Set/Coast Switch | Engine Data 1 | ON/OFF | OFF |
| Desired FRP Regulator | Fuel System | mA | 1,200-1,400 |
| Desired Fuel Rail Pressure | Engine Data 1 Engine Data 2 Fuel System |
MPa/PSI | 37-40 MPa (5,200-5,800 PSI) |
| Desired Idle Speed | Engine Data 1 | RPM | 630-700 |
| DTC Set This Ignition | Engine Data 1 | Yes/No | No |
| ECT Sensor | Engine Data 1 Fuel System |
°C/ °F | 85°C-105°C /185°F-220°F (varies with temperature) |
| Engine Oil Level Switch | Engine Data 1 | OK/Fault | OK |
| Engine Oil Life Remaining | Engine Data 1 | % | Varies |
| Engine Run Time | Engine Data 1 Engine Data 2 Fuel System |
Hrs/Mins/Sec | Varies with engine run time |
| Engine Speed | Engine Data 1 Engine Data 2 Fuel System |
RPM | +/-100 RPM from desired |
| FRP Regulator Command | Engine Data 1 Engine Data 2 Fuel System |
% | 40-50 |
| FRP Regulator Command | Fuel System | mA | Varies |
| FRP Regulator Relay | Engine Data 1 | ON/OFF | ON |
| FRP Regulator Fuel Flow | Fuel System | mm3 | Varies |
| Front Axle Switch | Engine Data 1 | Lock/Unlock | Unlock |
| Fuel Level Sensor | Fuel System | % | Varies |
| Fuel Temperature Sensor | Engine Data 1 Engine Data 2 Fuel System |
°C/°F | 10°C-90°C/50°F-194°F |
| Glow Plug Feed Back Signal | Engine Data 1 | Volts | 0.0-0.2 |
| Glow Plug Relay | Engine Data 1 | ON/OFF | OFF |
| Glow Plug System Type | Engine Data 1 | Federal/ California | Varies |
| IAT Sensor | Engine Data 1 | °C/°F | 10°C-90°C/50°F-194°F (temperatures may increase under heavy engine loads) |
| Ignition 1 Signal | Engine Data 1 | Volts | 12-14 (accuracy +/-0.4 volts) |
| Injector 1-8 Command | Engine Data 2 | ms | 0.3-0.5 |
| Intake Air Heater Feedback Signal | Engine Data 1 | Volts | 0.0 |
| Intake Air Heater | Engine Data 1 | ON/OFF | OFF |
| Intake Air Heater Relay Command | Engine Data 1 | ON/OFF | OFF |
| Low Coolant Level | Engine Data 1 | Yes/No | No |
| MAF Sensor | Engine Data 1 Fuel System |
g/s | 45-50 |
| Main Injection Command | Fuel System | microseconds | Varies |
| Main Injection Fuel Rate | Fuel System | mm3 | 6.5-8.5 |
| Main Injection Timing | Engine Data 1 Engine Data 2 Fuel System |
degrees | Varies |
| MIL Command | Engine Data 1 | ON/OFF | OFF |
| PCM in VTD Fail Enable | Engine Data 1 | Yes/No | No |
| PCM Reset | Engine Data 1 | Yes/No | No |
| Pilot Injection Command | Fuel System | microseconds | Varies |
| Pilot Injection Fuel Rate | Fuel System | mm3 | 0.8-1.0 |
| Pilot Injection Timing | Fuel System | degrees | Varies |
| PNP Switch | Engine Data 1 | Applied/Released | Released |
| Reverse Enable | Engine Data 1 | Yes/No | No |
| Start up ECT | Engine Data 1 | °C/°F | Varies (ECT at time of engine startup) |
| Stop Lamp Pedal Switch | Engine Data 1 | Applied/Released | Released |
| TCC/Cruise Brake Pedal Switch | Engine Data 1 | Open/Closed | Closed |
| Vehicle Speed Sensor | Engine Data 1 Fuel System |
mph/km/h | 0 |
| VTD Auto Learn Timer | Engine Data 1 | Active/Inactive | Inactive |
| VTD Fuel Disable | Engine Data 1 | Active/Inactive | Inactive |
| VTD Fuel Disable Until Ign. Off | Engine Data 1 | Yes/No | No |
| Wait To Start | Engine Data 1 | ON/OFF | OFF |
| Water In Fuel | Engine Data 1 | ON/OFF | OFF |