Diagnostic Starting Point - Engine Controls
Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check-Vehicle will provide the following information
- The identification of the control modules which command the system
- The ability of the control modules to communicate through the serial data circuit
- The identification of any stored diagnostic trouble codes (DTCs) and the codes' statuses
The use of the Diagnostic System Check-Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.
Scan Tool Data List
The Engine Scan Tool Data List contains all engine related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.
Use the Engine 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 Engine 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. |
Only the parameters listed below are referenced in this service manual for use in diagnosis. If all values are within the typical range described below, refer to for diagnosis.
The column labeled Data List indicates where a parameter can be located on the scan tool. Refer to the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed
| 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 | Eng 1 | Enabled/Disabled | Disabled |
| 4WD Signal | Eng 1 | Enabled/Disabled | Disabled |
| 5 volts Reference 1 | FS | Volts | Varies |
| 5 volts Reference 2 | FS | Volts | Varies |
| 5 volts Reference 3 | FS | Volts | Varies |
| A/C Clutch Feedback Signal | Eng 1 | Relay ON/OFF | Relay OFF |
| A/C High Side Pressure | Eng 1 | Volts | Varies |
| A/C Relay Command | Eng 1, EGR, TC | ON/OFF | Off |
| A/C Request Signal | Eng 1 | Yes/No | No |
| A/C Sec. High Press. SW | Eng 1 | Open/Closed | Closed |
| Actual Fuel Rail Pressure | All | MPa/PSI | 37-40 MPa (5,200-5,800 PSI) |
| APP Indicated Angle | All | % | 0.0 |
| APP Sensor 1 | Eng 1, FF/FR | Volts | 0.44-0.95 (Idle) 0.75-1.25 (2,500 RPM) |
| APP Sensor 2 | Eng 1, FF/FR | Volts | 3.9-4.5 (Idle) 3.7-4.3 (2,500 RPM) |
| APP Sensor 3 | Eng 1, FF/FR | Volts | 3.6-4.1 (Idle) 3.5-4.0 (2,500 RPM) |
| Balancing Rate Cyl. 1-8 | Eng 2, FF/FR | Mm 3 | 4.0 to +4.0 |
| BARO | Eng 1, EGR, TC, FF/FR | KPa | 65-104 (Varies with altitude) |
| Battery Voltage | Eng 1 | Volts | 12-14 (Accuracy +/- 0.4 Volts) |
| Boost Pressure Sensor | Eng 1, EGR, TC, FF/FR | KPa/PSI | 60-170 kPa (8-24 PSI) (All RPM) |
| Boost Pressure Sensor | TC | Volts | Varies |
| Calculated Fuel Rate | All | Mm 3 | 7-9 |
| CAM Reference Signal Missed | Eng 1 | Counts | 0 |
| CAM Signal Present | Eng 1 | Yes/No | Yes |
| Check Trans Lamp | Eng 1 | ON/OFF | OFF |
| CKP Sensor Pulses Missed | Eng 1 | Counts | 0 |
| Clutch Pedal Switch | Eng 1 | Applied/Released | Released |
| Cruise Control Active | Eng 1 | Yes/No | No |
| Cruise ON/OFF Switch | Eng 1 | ON/OFF | OFF |
| Cruise/Resume/Accel Switch | Eng 1 | ON/OFF | OFF |
| Cruise Set/Coast Switch | Eng 1 | ON/OFF | OFF |
| Crank Signal Present | Eng 1 | Yes/No | Yes |
| Desired EGR Position | EGR | % | Varies |
| Desired FRP Regulator | FS | MA | 1,200-1,400 |
| Desired Fuel Rail Pressure | All | MPa/PSI | 37-40 MPa (5,200-5,800 PSI) |
| Desired Idle Speed | Eng 1, FF/FR | RPM | 630-700 |
| Desired TC Vane Position | TC | % | 20% |
| Desired TC Vane Pos. Ctrl. Solenoid | TC | Amps | 0.1 |
| DTC Set This Ignition | Eng 1 | Yes/No | No |
| ECT Sensor | Eng 1, FS, EGR, TC, FF/FR | °C/°F | 85°C-105°C /185°F-220°F (Varies with temperature) |
| EGR Learned Minimum Position | EGR | % | Varies |
| EGR Position Sensor | EGR | Volts | Varies |
| EGR Position Sensor | EGR | % | Varies |
| EGR Position Variance | EGR | % | Varies |
| EGR Solenoid Command | EGR | % | Varies |
| Engine Oil Level Switch | Eng 1 | OK/Fault | OK |
| Engine Oil Life Remaining | Eng 1 | % | Varies |
| Engine Oil Pressure Sensor | FS | KPa/PSI | Varies |
| Engine Run Time | All | Hrs/Mins/Sec | Varies with engine run time |
| Engine Speed | All | RPM | +/-100 RPM from desired |
| Fail Counter | FR | Counts | Varies |
| FRP Regulator Command | Eng 1, Eng 2, FS, TC, FF/FR | % | 40-50 |
| FRP Regulator Command | FS, FF/FR | MA | Varies |
| FRP Regulator Relay | Eng 1 | ON/OFF | ON |
| FRP Regulator Fuel Flow Command | FS | Mm 3 | Varies |
| Front Axle Switch | Eng 1 | Lock/Unlock | Unlock |
| Fuel Level Sensor | FS | % | Varies |
| Fuel Level Sensor | FS | Volts | Varies with fuel level |
| Fuel Level Sensor Rear | FS | Volts | Varies |
| Fuel Temperature Sensor | Eng 1, Eng 2, FS, FF/FR | °C/°F | 10-90°C/50-194°F |
| Glow Plug Relay | Eng 1 | ON/OFF | OFF |
| GEN L Terminal Signal | Eng 1 | Voltage/No Voltage | No Voltage |
| High Idle Switch (if equipped) | Eng 1 | ON/OFF | OFF |
| IAT Sensor | Eng 1, EGR, TC, FF/FR | °C/°F | 10-90°C/50-194°F (temperatures may increase under heavy engine loads) |
| Ignition 1 Signal | Eng 1, EGR, TC, FF/FR | Volts | 12-14 (accuracy +/-0.4 volts) |
| Ignition Off Time | EGR, TC | Minutes | Varies |
| Injector 1-8 Command | Eng 2, FF/FR | Ms | 0.3-0.5 |
| Low Coolant Level | Eng 1 | Yes/No | No |
| MAF | Eng 1 | Volts | Varies |
| MAF Sensor | Eng 1, FS, EGR, TC, FF/FR | G/s | 45-50 |
| Main Injection Command | FS | Microseconds | Varies |
| Main Injection Fuel Rate | FS | Mm 3 | 6.5-8.5 |
| Main Injection Timing | Eng 1, Eng 2, FS, FF/FR | Degrees | Varies |
| MIL Command | Eng 1 | ON/OFF | OFF |
| Mileage Since First Failure | FF/FR | Miles/Km | Varies |
| Mileage Since Last Failure | FF/FR | Miles/Km | Varies |
| Not Run Counter | FR | Counts | Varies |
| Pass Counter | FR | Counts | Varies |
| PCM in VTD Fail Enable | Eng 1 | Yes/No | No |
| PCM Reset | Eng 1, EGR, TC | Yes/No | No |
| Pilot Injection Command | FS | Microseconds | Varies |
| Pilot Injection Fuel Rate | FS | Mm 3 | 0.8-1.0 |
| Pilot Injection Timing | FS | Degrees | Varies |
| PNP Switch | Eng 1, EGR | In Gear/Park/Neutral | Park/Neutral |
| PTO Enable | Eng 1 | YES/NO | NO |
| PTO Engage Relay Command | Eng 1 | ON/OFF | OFF |
| PTO Engine Shutdown Signal | Eng 1 | YES/NO | NO |
| PTO Feedback Signal | Eng 1 | Relay ON/Relay OFF | Relay OFF |
| Reverse Enable | Eng 1 | Yes/No | No |
| Start up ECT | Eng 1, FF/FR | °C/°F | Varies (ECT at time of engine startup) |
| Start up IAT | Eng 1 | °C/°F | Varies (IAT at time of engine startup) |
| Stoplamp Pedal Switch | Eng 1 | Applied/Released | Released |
| TC Vane Learned Closed Position | TC | Counts | Varies |
| TC Vane Learned Open Position | TC | Counts | Varies |
| TC Vane Position Learned | TC | Yes/No | Yes |
| TC Vane Position Sensor | TC | Amps | 0.1 |
| TC Vane Pos. Ctrl. Solenoid | TC | % | 70 |
| TCC/Cruise Brake Pedal Switch | Eng 1 | Applied/Released | Released |
| Vehicle Speed Sensor | Eng 1, FS, EGR, TC, FF/FR | Mph/km/h | 0 |
| VTD Auto Learn Timer | Eng 1 | Active/Inactive | Inactive |
| VTD Fuel Disable | Eng 1 | Active/Inactive | Inactive |
| VTD Fuel Disable Until Ign. Off | Eng 1 | Yes/No | No |
| Wait To Start | Eng 1 | ON/OFF | OFF |
| Water In Fuel | Eng 1 | ON/OFF | OFF |
Scan Tool Data List
Scan Tool Data Definitions
A list of each data message displayed on the scan tool will be explained in Engine Controls. This information will assist in emission or driveability problems. The displays can be viewed while the vehicle is being driven. Always perform the Diagnostic System Check - Engine Controls first. The Diagnostic System Check will confirm proper system operation.
Scan Tool Output Controls
| Scan Tool Output Control | Additional Menu Selection(s) | Description |
|---|---|---|
| Cylinder Power Balance | Fuel System | Disables each fuel injector. The device control will time out after 5 minutes unless changed or cancelled by the scan tool. Device Control can be changed at any engine or vehicle speed. |
| EGR Solenoid | Engine Output Controls | Activates the exhaust gas recirculation (EGR) solenoid ON or OFF. The EGR position is limited to 30 percent duty cycle, which is a fully open valve. The device control is limited to 10 seconds ON, with a 10 second OFF cooling time. |
| Fuel Pressure Control | Fuel System | Activates the Fuel Pressure Regulator in 10 percent increments from 0-100 percent. The Device Control will not change unless changed or cancelled by the scan tool. |
| Fuel Pump | Engine Output Controls | Activates the fuel transfer pump ON or OFF. The Device Control will not change unless changed or cancelled by the scan tool. |
| Glow Plug | Engine Output Controls | Activates the Glow Plug Controller ON or OFF. The Device Control will be aborted after 12 seconds for the first activation, and after 5 seconds for every other activation. Device control is inhibited if the engine is running. |
| Malfunction Indicator Lamp | Engine Output Controls | Activates the malfunction indicator lamp (MIL). The MIL will remain illuminated until cancelled by the scan tool. |
| RPM Control | Fuel System | Adjusts the engine speed in 25, 100, or 500 RPM increments. The Device Control will not change unless changed or cancelled by the scan tool. |
| TC Vane Sensor | Engine Output Controls | Adjusts the turbocharger vane position in 10 percent increments from 0-100 percent. The device control will be aborted if engine speed is above idle or the coolant temperature is too cold. |
| TC Vane Solenoid | Engine Output Controls | Cycles the turbocharger vane position solenoid to 100 percent boost and back to 0 percent boost. The vane position sensor is not accurate during this output control. The device control is limited to engine speeds less than 1500 RPM. |
Scan Tool Output Controls