Diagnostic Starting Point - Engine Controls
Begin the system diagnosis with Diagnostic System Check - Engine Controls . The Diagnostic System Check-Engine Controls 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-Engine Controls 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 Engine Controls Diagnostic Check is completed.
- No diagnostic trouble codes (DTCs)
- 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 |
| A/C Clutch Feedback Signal | Eng 1 | Relay ON/OFF | Relay OFF |
| A/C Relay Command | Eng 1, EGR | 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 | Eng1, FF/FR | Volts | 3.9-4.5 (Idle) 3.7-4.3 (2,500 RPM) |
| APP Sensor 3 | Eng1, 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, FF/FR | KPa | 65-104 (Varies with altitude) |
| Battery Voltage | Eng 1 | Volts | 12-14 (Accuracy +/- 0.4 Volts) |
| Boost Pressure Sensor | Eng 1, FF/FR | KPa/PSI | 60-170 kPa (8-24 PSI) (All RPM) |
| Calculated Fuel Rate | All | Mm 3 | 7-9 |
| CAM Reference Signal Missed | Eng 1 | Counts | 0 |
| 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 |
| 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 |
| DTC Set This Ignition | Eng 1 | Yes/No | No |
| ECT Sensor | Eng 1, FS, EGR, FF/FR | ° C/° F | 85° C-105° C /185° F-220° F (varies with temperature) |
| EGR Vacuum Sensor | EGR | KPa/PSI | 18 - 158 |
| EGR Solenoid Command | EGR | % | 35 - 45 |
| EGR Throttle Valve Solenoid Command | EGR | Open/Closed | Closed |
| EGR Vent Solenoid Command | EGR | Venting/Not Venting | Not Venting |
| Engine Oil Level Switch | Eng 1 | OK/Fault | OK |
| Engine Oil Life Remaining | Eng 1 | % | 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 | All | % | 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 Temperature Sensor | Eng 1, Eng 2, FS, FF/FR | ° C/° F | 10° C-90° C/50° F-194° F |
| Glow Plug Feed Back Signal | Eng 1 | Volts | 0.0-0.2 |
| Glow Plug Relay | Eng 1 | ON/OFF | OFF |
| GEN L Terminal | Eng 1 | Voltage/No Voltage | No Voltage |
| Glow Plug System Type | Eng 1 | Federal / California | Varies |
| Glow Plug Feedback Signal | Eng 1, FF/FR | Volts | Varies |
| High Idle Swtch-if equipped | Eng 1 | ON/OFF | OFF |
| IAT Sensor | Eng 1, EGR, FF/FR | ° C/° F | 10° C-90° C/50° F-194° F (temperatures may increase under heavy engine loads) |
| Ignition 1 Signal | Eng 1, EGR, FF/FR | Volts | 12-14 (accuracy +/-0.4 volts) |
| Injector 1-8 Command | Eng 2, FF/FR | Ms | 0.3-0.5 |
| Intake Air Heater Feedback Signal | Eng 1 | Relay ON/OFF | Relay OFF |
| Intake Air Heater | Eng 1 | Volts | 0 |
| Intake Air Heater Relay Command | Eng 1 | ON/OFF | OFF |
| Low Coolant Level | Eng 1 | Yes/No | No |
| MAF Sensor | Eng 1, FS, EGR, 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 | 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) |
| Stop Lamp Pedal Switch | Eng 1 | Applied/Released | Released |
| TCC/Cruise Brake Pedal Switch | Eng 1 | Applied/Released | Released |
| Vehicle Speed Sensor | Eng 1, FS, EGR, 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 |
Engine 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 injector. The Device control will not change unless changed or cancelled by the scan tool. Device Control can be changed at any engine or vehicle speed. |
| EGR Throttle Valve Solenoid | Engine Output Controls | Activates the exhaust gas recirculation (EGR) throttle valve solenoid ON or OFF. The Device Control will not change unless changed or cancelled by the scan tool. |
| EGR Solenoid | Engine Output Controls / EGR System | Activates the EGR control solenoid in 10 percent increments from 0-100 percent. The Device Control will not change unless changed or cancelled by the scan tool. |
| EGR System Seal | Engine Output Controls / EGR System | Activates the EGR vent solenoid Not Venting. Commands the EGR Solenoid to 0 %. This seals the EGR vacuum system. The Device Control will not change unless changed or cancelled by the scan tool. |
| EGR Vent | Engine Output Controls / EGR System | Activates the EGR vent solenoid ON or OFF. The Device Control will not change unless changed or cancelled by the scan tool. |
| Fuel Pressure Control | Engine Output Controls | 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. |
| FRP Regulator Relay | Engine Output Controls | Activates the FRP Regulator Relay, ignition 1 relay ON or OFF. The Device Control will not change unless changed or cancelled by the scan tool. DTC U1800 may set when turning the relay OFF. |
| Glow Plug | Engine Output Controls | Activates the Glow Plug Relay ignition 1 relay 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. |
| Intake Air Heater | Engine Output Controls | Activates the intake air heater relay ON or OFF. The Device Control will not change unless changed or cancelled by the scan tool. |
| 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. |
Scan Tool Output Controls
Diagnostic Trouble Code (DTC) List
| DTC | Diagnostic Procedure | Modules |
|---|---|---|
| P0016 | DTC P0016 | ECM |
| P0087 | DTC P0087 | ECM |
| P0088 | DTC P0088 | ECM |
| P0089 | DTC P0089 | ECM |
| P0090 | DTC P0090 | ECM |
| P0101 | DTC P0101 | ECM |
| P0102 | DTC P0102 | ECM |
| P0103 | DTC P0103 | ECM |
| P0112 | DTC P0112 | ECM |
| P0113 | DTC P0113 | ECM |
| P0116 | DTC P0116 | ECM |
| P0117 | DTC P0117 | ECM |
| P0118 | DTC P0118 | ECM |
| P0128 | DTC P0128 | ECM |
| P0168 | DTC P0168 | ECM |
| P0181 | DTC P0181 | ECM |
| P0182 | DTC P0182 | ECM |
| P0183 | DTC P0183 | ECM |
| P0192 | DTC P0192 | ECM |
| P0193 | DTC P0193 | ECM |
| P0201-P0208 | DTC P0201-P0208 | ECM |
| P0234 | DTC P0234 (Federal RPO FE9, NG1) or DTC P0234 (California RPO YF5, NE1, and VCL) | ECM |
| P0236 | DTC P0236 (California RPO YF5, NE1, and VCL) or DTC P0236 (Federal RPO FE9, NG1) | ECM |
| P0237 | DTC P0237 (California RPO YF5, NE1, and VCL) or DTC P0237 (Federal RPO FE9, NG1) | ECM |
| P0238 | DTC P0238 (California RPO YF5, NE1, and VCL) or DTC P0238 (Federal RPO FE9, NG1) | ECM |
| P0300 | DTC P0300 (Federal Emissions) or DTC P0300 (California Emissions, and RPO VCL) | ECM |
| P0301-P0308 | DTC P0301-P0308 (Federal Emissions) or DTC P0301-P0308 (California Emissions, and RPO VCL) | ECM |
| P0335 | DTC P0335 | ECM |
| P0336 | DTC P0336 | ECM |
| P0340 | DTC P0340 | ECM |
| P0341 | DTC P0341 | ECM |
| P0370 | DTC P0370 or P0374 | ECM |
| P0374 | DTC P0370 or P0374 | ECM |
| P0380 | DTC P0380 (Federal RPO FE9, NG1) or DTC P0380 (California RPO YF5, NE1) | ECM |
| P0381 | DTC P0381 in Instrument Panel, Gages and Console | ECM |
| P0401 | DTC P0401 | ECM |
| P0404 | DTC P0404 | ECM |
| P0405 | DTC P0405 | ECM |
| P0406 | DTC P0406 | ECM |
| P0461 | DTC P0461 (4.3L, 4.8L, 6.0L, 6.6L, 8.1L Engines) or DTC P0461 (5.3L Engine) in Instrument Panel, Gages and Console | ECM |
| P0462 | DTC P0462 (4.3L, 4.8L, 6.0L, 6.6L, 8.1L Engines) or DTC P0462 (5.3L Engine) in Instrument Panel, Gages and Console | ECM |
| P0463 | DTC P0463 (4.3L, 4.8L, 6.0L, 6.6L, 8.1L Engines) or DTC P0463 (5.3L Engine) in Instrument Panel, Gages and Console | ECM |
| P0489 | DTC P0489 | ECM |
| P0490 | DTC P0490 | ECM |
| P0500 | DTC P0500 (8.1L) or DTC P0500 (6.6L) in Manual Transmission - ZF S6-650 | ECM |
| P0522 | DTC P0522 (4.3L, 4.8L, 5.3L, 6.0L, 6.6L, 8.1L) or DTC P0522 (6.6L (LB7) Engine) in Instrument Panel, Gages and Console | ECM |
| P0523 | DTC P0523 in Instrument Panel, Gages and Console | ECM |
| P0530 | DTC P0530 (LU3, LR4, LM7, LQ4 and L18) or DTC P0530 (LB7) in HVAC-Automatic DTC P0530 (LU3, LR4, LM7, LQ4, and L18) or DTC P0530 (LB7) in HVAC-Manual | ECM |
| P0540 | DTC P0540 | ECM |
| P0543 | DTC P0543 | ECM |
| P0562 | DTC P0562 in Engine Electrical | ECM |
| P0563 | DTC P0563 in Engine Electrical | ECM |
| P0567 | DTC P0567 (4.8L, 5.3L, 6.0L, and 8.1L) or DTC P0567 (6.6L) in Cruise Control | ECM |
| P0568 | DTC P0568 (4.8L, 5.3L, 6.0L, and 8.1L) or DTC P0568 (6.6L) in Cruise Control | ECM |
| P0571 | DTC P0571 (4.8L, 5.3L, 6.0L, and 8.1L) or DTC P0571 (6.6L) in Cruise Control | ECM |
| P0601 | DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 | ECM |
| P0602 | DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 | ECM |
| P0603 | DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 | ECM |
| P0604 | DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 | ECM |
| P0611 | DTC P0611 | ECM |
| P0612 | DTC P0612 | ECM |
| P0641 | DTC P0641 | ECM |
| P0650 | DTC P0650 | ECM |
| P0651 | DTC P0651 | ECM |
| P0700 | DTC P0700 | ECM |
| P0802 | DTC P0802 | ECM |
| P0833 | DTC P0833 (8.1L) or DTC P0833 (6.6L) in Manual Transmission - ZF S6-650 | ECM |
| P1093 | DTC P1093 | ECM |
| P1094 | DTC P1094 | ECM |
| P1125 | DTC P1125 | ECM |
| P1172 | DTC P1172 | ECM |
| P1223 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1226 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1229 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1232 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1235 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1238 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1241 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1244 | DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 | ECM |
| P1270 | DTC P1270 | ECM |
| P1404 | DTC P1404 | ECM |
| P1550 | DTC P1550 | ECM |
| P1621 | DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 | ECM |
| P1626 | DTC P1626 in Theft Deterrent | BCM |
| P1631 | DTC P1631 in Theft Deterrent | BCM |
| P1637 | DTC P1637 in Engine Electrical | ECM |
| P1658 | DTC P1658 | ECM |
| P2066 | DTC P2066 (4.3L, 4.8L, 6.0L, 6.6L, 8.1L Engines) or DTC P2066 (5.3L Engine) In Instrument Panel, Gages and Console | ECM |
| P2067 | DTC P2067 (4.3L, 4.8L, 6.0L, 6.6L, 8.1L Engines) or DTC P2067 (5.3L Engine) In Instrument Panel, Gages and Console | ECM |
| P2068 | DTC P2068 (4.3L, 4.8L, 6.0L, 6.6L, 8.1L Engines) or DTC P2068 (5.3L Engine) In Instrument Panel, Gages and Console | ECM |
| P2122 | DTC P2122 | ECM |
| P2123 | DTC P2123 | ECM |
| P2127 | DTC P2127 | ECM |
| P2128 | DTC P2128 | ECM |
| P2132 | DTC P2132 | ECM |
| P2133 | DTC P2133 | ECM |
| P2138 | DTC P2138 | ECM |
| P2139 | DTC P2139 | ECM |
| P2140 | DTC P2140 | ECM |
| P2141 | DTC P2141 | ECM |
| P2142 | DTC P2142 | ECM |
| P2144 | DTC P2144 | ECM |
| P2145 | DTC P2145 | ECM |
| P2146 | DTC P2146 | ECM |
| P2149 | DTC P2149 | ECM |
| P2227 | DTC P2227 (Federal RPO FE9, NG1) or DTC P2227 (California RPO YF5, NE1, and VCL) | ECM |
| P2228 | DTC P2228 (Federal RPO FE9, NG1) or DTC P2228 (California RPO YF5, NE1, and VCL) | ECM |
| P2229 | DTC P2229 (Federal RPO FE9, NG1) or DTC P2229 (California RPO YF5, NE1, and VCL) | ECM |
| P2279 | DTC P2279 | ECM |
| P2610 | DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610 | ECM |
| UXXXX | Diagnostic Trouble Code (DTC) List in Data Link Communications. | ECM, EBCM, EVO/Passlock, TCM, IPC |
Diagnostic Trouble Code (DTC) List