| Table 1: | Scan Tool Data Parameters |
| Table 2: | Special Functions |
The GPCM Scan Tool Data List contains all glow plug control module related parameters that are available on the scan tool. The list is arranged in alphabetical order.
Use the GPCM Scan Tool Data List only after the following is determined:
| • | The Diagnostic System Check - Vehicle is completed. |
| • | No diagnostic trouble codes (DTCs) are present. |
| • | The on-board diagnostics are functioning properly. |
Scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The GPCM Scan Tool Data List represents values that would be seen on a normal running engine.
Important: A scan tool that displays faulty data should not be used. The scan tool problem should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.
Parameter | System State | Expected Value | Description |
|---|---|---|---|
Base Operating Conditions: Engine Idling/Radiator Hose Hot/Park or Neutral/Closed Loop/Accessories Off | |||
Ignition 1 Signal | -- | 13-15 Volts | 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. |
Glow Plug Command Signal | -- | OFF | This parameter displays the commanded state of the glow plugs. The scan tool will display ON or OFF |
Glow Plug | -- | 14 Volts | This parameter displays the voltage supply to the glow plugs as measured by the control module. The scan tool will display a higher value at high voltages, or a lower value at lower voltages. |
Glow Plug 1-8 | -- | 19-21 Amp | This parameter indicates the current of the individual glow plug circuits as calculated by the control module. The scan tool will display a higher value for more current, and a lower value for less current. |
Glow Plug 1-8 | -- | 0.49-0.9 Ohms | This parameter indicates the resistance of the individual glow plug circuits as calculated by the control module. The scan tool will display a higher value for more resistance, and a lower value for less resistance. |
Glow Plug Driver Shorted | -- | OK | This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an short on the circuit. |
Glow Plug Overvoltage | -- | OK | This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the glow plug voltage is too high. |
Glow Plug Undervoltage | -- | OK | This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the glow plug voltage is too low. |
Glow Plug Overtemp | -- | OK | This parameter displays the diagnostic state of the output driver for the intake air heater (IAH). The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if the circuit is shorted to ground. |
IA Heater Command Signal | -- | Off | This parameter displays if the heater is commanded on by the control module. |
Intake Air Heater | -- | 11-13.2 Volts | This parameter displays the status of the IAH as commanded by the control module. |
Intake Air Heater | -- | 0% | This parameter displays duty cycle of the IAH as commanded by the control module. |
IAH Cmd 2 Ckt Command | -- | OFF | This parameter displays a second command ON or OFF The command one and two must be ON in order for the IAH to turn on. |
IA Heater Overtemp | -- | OK | This parameter displays the diagnostic state of the output driver for the IAH. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the IAH temperature is too high. |
IA Heater Overvoltage | -- | OK | This parameter displays the diagnostic state of the output driver for the IAH. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the IAH voltage is too high. |
IA Heater Undervoltage | -- | OK | This parameter displays the diagnostic state of the output driver for the IAH. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the IAH voltage is too low. |
IA Heater Driver Ground | -- | OK | This parameter displays the diagnostic state of the output driver for the IAH. The scan tool will display OK if the IAH is properly grounded. The scan tool will display Fault if the control module detects that the IAH is not grounded. |
IA Heater Driver Open | -- | OK | This parameter displays the diagnostic state of the output driver for the IAH. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the IAH driver is open. |
IA Heater Driver Shorted | -- | OK | This parameter displays the diagnostic state of the output driver for the IAH. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the IAH driver is shorted. |
IA Heater Driver Current | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
IAH Temp Ckt Status | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
IAH Feedback Ckt. Status | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
IAH Cmd 1 Ckt. Status | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
IAH Cmd 2 Ckt. Status | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
IAH Resistance Status | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
IAH Voltage Status | -- | OK | This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present. |
Parameter | Description |
|---|---|
Glow Plug | This function commands the Glow Plugs ON/OFF |
Intake Air Heater | This function commands the IAH ON/OFF. |
