EPC ERROR CODES

John Deere EPC fault codes / John Deere EPC diagnostic trouble codes

EPC Control Unit – Control unit for PowrQuad PLUS and AutoQuad transmissions

EPC 000084.07 ( EPC 84.0 )— Wheel Speed Detected During Calibration of Transmission
The diagnostic trouble code is generated when the control unit EPC receives a wheel speed signal via CAN BUS during calibration. Reasons may be:
• defective wheel speed sensor (B09/B35).
• incorrect wheel speed received via CAN BUS.
• the tractor is not standing on a level surface during the calibration. The tractor can therefore move during the calibration (ground speed exists).

EPC 000084.14 ( EPC 84.14 )— B09/B35 Wheel Speed Sensor, Fault
The diagnostic trouble code is generated when the EPC registers no wheel speed with transmission connected to the engine (clutch pedal released) and reverse drive lever in forward or reverse position. Reasons may be:
• defective wheel speed sensor (B09/B35).
• incorrect wheel speed received via CAN BUS.

EPC 000084.19 ( EPC 84.19 )— Incorrect CAN BUS Message, Wheel Speed from BCU
The diagnostic trouble code is generated when the BCU control unit transmits the following sensor status via CAN BUS:
• Sensor not available (due to incorrect configuration of wheel speed sensor).
• Sensor signal faulty (circuit problem at wheel speed sensor).

EPC 000091.03 ( EPC 91.03 )— B79 Accelerator Pedal Potentiometer, Voltage Too High
The diagnostic trouble code is generated when the control unit measures a voltage in excess of 4.7 volts at the signal input of the accelerator pedal potentiometer (B79). This indicates that circuit is shorted to a supply lead or is open.

EPC 000091.04 ( EPC 91.04 )— B79 Accelerator Pedal Potentiometer, Voltage Too Low
The diagnostic trouble code is generated when the control unit measures a voltage below 0.3 volts at the signal input of the accelerator pedal potentiometer (B79). This indicates a short to ground in the circuit.

EPC 000091.07 ( EPC 91.07 )— Incorrect CAN BUS message, Accelerator pedal position from ECU
Diagnostic trouble code is released, when the selection from the foot throttle on input address EPC025 on the premium tractors has been deactivated.

EPC 000091.19 ( EPC 91.19 )— Incorrect CAN BUS Message, Engine Speed from ECU
The diagnostic trouble code is generated when the ECU is not able to supply the CAN BUS message concerning engine speed (CAN BUS message incorrect or missing).

EPC 000092.19 ( EPC 92.19 )— Incorrect CAN BUS Message, Engine Load from ECU
The diagnostic trouble code is generated when the ECU is not able to supply the CAN BUS message concerning engine load (CAN BUS message incorrect or missing).

EPC 000126.16 ( EPC 126.16 )— Transmission Oil Filter Restricted
The diagnostic trouble code is generated when the pressure switch on transmission oil filter was closed for more than three seconds at a transmission oil temperature of above 28°C (82°F) and an engine speed of more than 700 rpm. This indicates that the transmission oil filter is restricted. Change the transmission oil filter.

EPC 000127.01 ( EPC 127.01 )— Transmission Oil Pressure Too Low
The diagnostic trouble code is generated when the EPC detects low transmission oil pressure (system pressure) at an engine speed above 700 rpm.

EPC 000158.03 ( EPC 158.03 )— Control Unit, Supply Voltage Too High
The diagnostic trouble code is generated when the control unit registers a supply voltage above 16 volts.

EPC 000158.04 ( EPC 158.04 )— Control Unit, Supply Voltage Too Low
The diagnostic trouble code is generated when the control unit registers a supply voltage of less than 9 volts.

EPC 000177.00 ( EPC 177.00 )— Transmission Oil Temperature Very High
The diagnostic trouble code is generated when the transmission oil temperature exceeds 106°C (223°F).

EPC 000177.03 ( EPC 177.03 )— B60 Sensor for Transmission Oil Temperature, Voltage Too High
This diagnostic trouble code is generated if the control unit detects that the voltage at the signal input of transmission oil temperature sensor (lead 6002) is too high. Temperature value is below 34° C (29° F). This indicates that the sensor’s circuit is open or shorted to a positive lead.

EPC 000177.04 ( EPC 177.04 )— B60 Sensor for Transmission Oil Temperature, Voltage Too Low
This diagnostic trouble code is generated if the control unit detects that the voltage at the signal input of transmission oil temperature sensor (lead 6002) is too low. Temperature value is above 125°C (257°F). This indicates a short to ground in the sensor circuit.

EPC 000177.16 ( EPC 177.16 )— Transmission Oil Temperature High
The diagnostic trouble code is generated when the transmission oil temperature is between 101°C (214°F) and 105°C (221°F).

EPC 000190.08 ( EPC 190.08 )— Engine Speed Signal Incorrect
The diagnostic trouble code is generated when the EPC
• receives an engine speed signal between 2 and 299 rpm from the ECU for three seconds via the direct line (lead 6101).
• can neither receive the engine speed via the CAN BUS signal nor via the direct line for more then three seconds. This diagnostic trouble code can also be caused due to stalling of the engine.

EPC 000190.19 ( EPC 190.19 )— Incorrect CAN BUS Message, Engine Speed from ECU
The diagnostic trouble code is generated if the ECU cannot determine the engine speed and so cannot provide the CAN BUS with any data. A transmitted replacement value generates this diagnostic trouble code in the EPC. In its active state, this fault also generates a diagnostic trouble code at the ECU. The ECU diagnostic trouble code takes priority.

EPC 000191.00 ( EPC 191.00 )— Transmission Speed During Calibration Too High
The diagnostic trouble code is generated when the EPC registers a transmission speed during the calibration of the transmission. Reasons may be:
• defective transmission speed sensor (B104/B172).
• the tractor is not standing on a level surface during the calibration. The tractor can therefore move during the calibration (transmission speed exists).

EPC 000191.17 ( EPC 191.17 )— Transmission Speed Too Low
The diagnostic trouble code is generated when, with engine running the EPC commands forward or reverse movement but registers no or too low transmission speed. The reasons for this are:
• Circuit problem at the transmission speed sensor (B104).
• Circuit problem at the forward solenoid valve (Y33) or reverse solenoid valve (Y36).
• Circuit problem at the proportional solenoid valve for transmission enable (Y38).
• Forward solenoid valve (Y33), reverse solenoid valve (Y36) or proportional solenoid valve for transmission enable (Y38) stuck closed.

EPC 000237.02 ( EPC 237.02 )— VIN Information, Mismatch
The diagnostic trouble code is generated when the Vehicle Identification Number (VIN) from other control units is not the same.

EPC 000237.14 ( EPC 237.14 )— VIN Information, System DeActivated
The diagnostic trouble code is generated when the VIN security function was not enabled due to an internal problem. This indicates an incorrect reprogramming of the control unit.

EPC 000237.31 ( EPC 237.31 )— VIN Information, Incorrect
The diagnostic trouble code is generated when the vehicle identification number from other control units is not received or incorrectly received. All active VIN participants have to send the programmed vehicle identification number to the EPC at regular intervals.

EPC 000598.02 ( EPC 598.02 )— S72 Clutch Pedal Switch, Fault
The diagnostic trouble code is generated when the position of the clutch pedal switch (S72) does not match the voltage value of the clutch pedal potentiometer (B65).

EPC 000628.02 ( EPC 628.02 )— Control Unit Internal Fault
The diagnostic trouble code is generated when the control unit detects an internal problem during initializing (control unit boot sequence after the ignition is switched ON).

EPC 000628.12 ( EPC 628.12 )— Control Unit Internal Fault
This diagnostic trouble code is generated when an electronic malfunction is registered in the control unit.

EPC 000628.13 ( EPC 628.13 )— Control Unit Internal Fault
Diagnostic trouble code is generated when an electronic malfunction is registered in the control unit.

EPC 000629.12 ( EPC 629.12 )— Control Unit Internal Fault
The diagnostic trouble code is generated when the control unit internally detects that too much time has elapsed (watchdog).

EPC 000630.14 ( EPC 630.14 )— Incorrect Calibration Value
The diagnostic trouble code is generated when one or more calibration values (forward clutch fill pressure, reverse brake fill pressure, forward clutch fill time, reverse brake fill time) are out of allowed range.

EPC 000639.12 ( EPC 639.12 )— Power Train CAN BUS, High Error Rate
This diagnostic trouble code is generated when the control unit receives too many incorrect CAN BUS messages or when it detects a general problem in the connection to the power train CAN BUS.

EPC 000734.05 ( EPC 734.05 )— Y33 Forward Solenoid Valve, Current Too Low
The diagnostic trouble code is generated when the control unit registers an open circuit at the signal input of forward solenoid valve (Y33).

EPC 000735.05 ( EPC 735.05 )— Y36 Reverse Solenoid Valve, Current Too Low
The diagnostic trouble code is generated when the control unit registers an open circuit at the signal input of reverse solenoid valve (Y36).

EPC 000736.05 ( EPC 736.05 )— Y40 Gear Selector Solenoid Valve K1, Current Too Low
The diagnostic trouble code is generated when the control unit registers an open circuit at the signal input of gear selector solenoid valve K1 (Y40).

EPC 000737.05 ( EPC 737.05 )— Y39 Gear Selector Solenoid Valve K2, Current Too Low
The diagnostic trouble code is generated when the control unit registers an open circuit at the signal input of gear selector solenoid valve K2 (Y39).

EPC 000974.03 ( EPC 974.03 )— B96 Hand Throttle Potentiometer, Voltage Too High
This diagnostic trouble code is generated when the control unit measures a voltage in excess of 4.7 volts at the signal input of hand throttle potentiometer (B96, lead 6018). This indicates a short to a positive lead, an open circuit or a problem with the ground connection in the potentiometer’s circuit.

EPC 000974.04 ( EPC 974.04 )— B96 Hand Throttle Potentiometer, Voltage Too Low
This diagnostic trouble code is generated when the control unit measures a voltage below 0.3 volts at the signal input of hand throttle potentiometer (B96, lead 6018). This indicates a short to ground or a problem with the potentiometer supply voltage.

EPC 001079.02 ( EPC 1079.02 )— 5-volt Power Supply, Fault
The diagnostic trouble code is generated when the control unit detects several incorrect output signals from the 5-volt components (clutch pedal potentiometer B65, accelerator pedal potentiometer B79, hand throttle potentiometer B96 and enable pressure sensor B105). This indicates a problem in the 5-volt power supply. The diagnostic trouble code triggers the alarm level “Information”.

EPC 001079.03 ( EPC 1079.03 )— 5-volt Power Supply, Voltage Too High
The diagnostic trouble code is generated when the EPC measures more than 5.2 volts at the positive lead of the power supply to the 5-volt components (clutch pedal potentiometer B65, accelerator pedal potentiometer B79, hand throttle potentiometer B96 and enable pressure sensor B105). This indicates that the circuit is shorted to a positive supply lead or there is an internal interruption at the control unit.

EPC 001079.04 ( EPC 1079.04 )— 5-volt Power Supply, Voltage Too Low
The diagnostic trouble code is generated when the EPC measures less than 4.8 volts at the positive lead of the power supply to the 5-volt components (clutch pedal potentiometer B65, accelerator pedal potentiometer B79, hand throttle potentiometer B96 and enable pressure sensor B105). This indicates a short to ground in the circuit.

EPC 001666.03 ( EPC 1666.03 )— S102/S158 AutoMode Switch, Voltage Too High
The diagnostic trouble code is generated when the EPC detects that the AutoMode switch is activated during startup. This indicates a short to a supply lead somewhere in the circuit.

EPC 001713.02 ( EPC 1713.02 )— B111 Sensor for Hydraulic Oil Filter, Fault
The diagnostic trouble code is generated when, with open filter alarm level 1 switch (350 kPa; 3.5 bar; 51 psi) at hydraulic oil filter, the filter alarm level 2 switch (450 kPa; 4.5 bar; 65 psi) at hydraulic oil filter has been closed for more than 3 seconds at a hydraulic oil temperature above 28°C (82°F) and an engine speed above 700 rpm. This indicates a sensor problem or a dirty hydraulic oil filter.

EPC 001713.15 ( EPC 1713.15 )— Hydraulic Oil Filter Dirty
The diagnostic trouble code is generated when the filter alarm level 1 switch at hydraulic oil filter was closed for more than three seconds at a transmission oil temperature of above 28°C (82°F) and an engine speed of more than 700 rpm. The switch closes at a differential filter pressure of 350 kPa (3.5 bar; 51 psi) +/20 kPa (0.2 bar; 2.9 psi). This indicates that the hydraulic oil filter is dirty. Change the hydraulic oil filter.

EPC 001713.16 ( EPC 1713.16 )— Hydraulic Oil Filter Restricted
The diagnostic trouble code is generated when the filter alarm level 2 switch at hydraulic oil filter was closed for more than three seconds at a transmission oil temperature of above 28°C (82°F) and an engine speed of more than 700 rpm. The switch closes at a differential filter pressure of 425 kPa (4.25 bar; 62 psi) +/25 kPa (0.25 bar; 3.6 psi). This indicates that the hydraulic oil filter is dirty. Change the hydraulic oil filter.

EPC 002000.09 ( EPC 2000.09 )— Incorrect CAN BUS Message, Information from ECU
This diagnostic trouble code is generated when a data transfer problem occurs between the ECU and EPC. Reception of the CAN message regarding coolant temperature is intermittent or nonexistent (intermittent reception could be due to a loose wire).

EPC 002033.09 ( EPC 2033.09 )— Incorrect CAN BUS Message, Information from BCU
This diagnostic trouble code is generated when a data transfer problem occurs between the BCU and EPC. Reception of the CAN message from the BCU control unit regarding the status of the frontwheel drive is intermittent or nonexistent (intermittent reception could be due to a loose wire). The missing CAN message is ignored by the EPC control unit once engagement of frontwheel drive has been reported by the BCU control unit.

EPC 002408.19 ( EPC 2408.19 )— Incorrect CAN BUS Message, Rear PTO Engagement from BCU
The diagnostic trouble code is generated when the BCU control unit transmits the following sensor status via CAN BUS:
• Sensor not available (due to incorrect configuration of rear PTO switch).
• Faulty sensor signal (circuit problem at rear PTO switch).

EPC 522506.04 — A82 Reverse Drive Lever, Neutral Switch Opened by Mistake
The diagnostic trouble code is generated when the EPC control unit detects a closed notneutral switch although the reverse drive lever is in neutral position.

EPC 522506.31 — INFORMATION FOR OPERATOR: Neutral Switch Closed During StartUp
The diagnostic trouble code is generated when the EPC control unit detects that the neutral switch is closed during starting (ignition ON).

EPC 523652.02 — Control Unit Connected to Wrong Wiring Harness Connector
The diagnostic trouble code is generated when the control unit detects an erroneous signal in the circuit of the control unit identification during initializing (control unit boot sequence after the ignition is switched ON).

EPC 523677.02 — S158 Declutch Switch on Range Shift Lever Faulty
The voltage value of the declutch switch on the range shift lever is compared to the tractor system voltage. The diagnostic trouble code is generated if the EPC control unit detects that the voltage difference is too high when the declutch switch on the range shift lever is actuated. This indicates a problem with the declutch switch on the range shift lever (faulty, dirty or worn).

EPC 523677.03 — S158 Declutch Switch on Range Shift Lever, Signal Voltage too High
The voltage value of the declutch switch on the range shift lever is compared to the tractor system voltage. The diagnostic trouble code is generated if the EPC control unit detects that the signal voltage in the circuit of the declutch switch is too high when the declutch switch on the range shift lever is actuated. Reasons may be:
• Declutch switch on range shift lever defective.
• Signal voltage of declutch switch on range shift lever is shorted to system voltage
• Open ground connection to shift knob (pin 2C) (broken lead 310, terminal slid off, loose wire)

EPC 523677.04 — S158 Declutch Switch on Range Shift Lever, Signal Voltage too Low
The voltage value of the declutch switch on the range shift lever is compared to the tractor system voltage. The diagnostic trouble code is generated if the EPC control unit detects that the signal voltage in the circuit of the declutch switch is too low when the declutch switch on the range shift lever is actuated. Reasons may be:
• Declutch switch on range shift lever defective.
• Signal voltage of declutch switch on range shift lever is shorted to ground or the circuit is open (broken lead, terminal slid off, loose wire).

EPC 523677.07 — S158 Declutch Switch on Range Shift Lever, Voltage Too High During StartUp
The diagnostic trouble code is generated when the EPC control unit detects an activated declutch switch on range shift lever during the starting procedure (with range shift lever not in park position). Reasons may be:
• Operator error (declutch switch on range shift lever has been actuated by the operator during startup).
• Declutch switch on range shift lever defective.
• Signal voltage of declutch switch on range shift lever is shorted to system voltage

EPC 523677.14 — INFORMATION FOR OPERATOR: Declutch Switch on Range Shift Lever Deactivated
The diagnostic trouble code is generated if a range shift lever with declutch switch is equipped (diagnostic address EPC168 set to “1”) and the EPC control unit detects that the declutch switch is deactivated (diagnostic address EPC167 set to “0”). This diagnostic trouble code can also occur as a subsequent fault in connection with diagnostic trouble codes EPC 523677.03, EPC 523677.04 and EPC 523677.07.

EPC 523677.31 — S158 Declutch Switch on Range Shift Lever Deactivated, No Operator Present
This operator information (diagnostic trouble code) is generated if the declutch switch on range shift lever has been actuated but there is no valid signal to indicate that the operator is present (operator on seat, clutch or brake pedals depressed). A valid signal to indicate that the operator is present must be received at least 3 seconds prior to actuation. The diagnostic trouble code may also be generated due to an operator error (operator not on seat shortly before/during the actuation of the declutch switch).

EPC 523961.07 — INFORMATION FOR OPERATOR: Reverse Drive Lever Not in Neutral Position while Park Lock is Engaged
This operator information (diagnostic trouble code) is generated when the EPC control unit detects an active signal from the park lock switch (range shift lever in park position) and at the same time the reverse drive lever is not in neutral position. This operator information is also generated when the operator moves the reverse drive lever to the forward or reverse position while the range shift lever is in park position.

EPC 523966.31 — INFORMATION FOR OPERATOR: ComeHome Mode Activated
This operator information (diagnostic trouble code) is generated when the comehome mode is activated (K07/04 or K03/04 connector for comehome feature in “COME HOME” position). The comehome mode can only be activated within the first 2.5 seconds after starting the engine when the connector for the comehome feature is in “COME HOME” position and the reverse drive lever in neutral position.

EPC 523969.11 — S102/S158 Gear Selector Switch, Voltage Too High During StartUp
The diagnostic trouble code is generated when the EPC control unit detects an activated gear selector switch (upshift or downshift) during the starting procedure.

EPC 524020.31 — INFORMATION FOR OPERATOR: Reverse Drive Lever Not in Neutral Position During StartUp
The operator information (diagnostic trouble code) is generated when the EPC control unit detects an active forward, reverse or notneutral switch during the starting procedure. It may also be that an operator error has occurred: Reverse drive lever not in neutral position during startup.

EPC 524023.31 — A82 Reverse Drive Lever, Forward Switch or Reverse Switch Closed, But NotNeutral Switch Open
The diagnostic trouble code is generated when the control unit receives an incorrect switch signal combination from the reverse drive lever (notneutral switch open, forward or reverse switch closed).

EPC 524024.31 — A82 Reverse Drive Lever, Forward and Reverse Switches Actuated At Same Time
The diagnostic trouble code is generated when the control unit receives an incorrect switch signal combination from the reverse drive lever (forward and reverse switches actuated at the same time).

EPC 524025.31 — A82 Reverse Drive Lever, Forward Switch or Reverse Switch Open, But NotNeutral Switch Closed
The diagnostic trouble code is generated when the control unit receives an incorrect switch signal combination from the reverse drive lever (notneutral switch closed, forward or reverse switch open).

EPC 524029.02 — B65 Clutch Pedal Potentiometer, Voltages at Channel 1 and Channel 2 not in the Correct Ratio
The diagnostic trouble code is generated when the control unit detects a mismatch between the output signals of clutch pedal potentiometer (B65). The voltage at channel 1 (lead 6114) must be double the voltage of channel 2 (lead 6007).

EPC 524029.03 — B65 Clutch Pedal Potentiometer, Voltage at Channel 1 Too High
This diagnostic trouble code is generated when the control unit measures a voltage of more than 4.7 volts at the signal input from channel 1 of the potentiometer (B65, lead 6114). This indicates a problem at the signal lead or at the potentiometer ground connection.

EPC 524029.04 — B65 Clutch Pedal Potentiometer, Voltage at Channel 1 Too Low
This diagnostic trouble code is generated when the control unit measures a voltage of less than 0.3 volts at the signal input from channel 1 of the potentiometer (B65, lead 6114). This indicates a problem at the signal lead or a problem with the potentiometer supply voltage.

EPC 524173.02 — B65 Clutch Pedal Potentiometer, Voltages at Channel 1 and Channel 2 not in the Correct Ratio
The diagnostic trouble code is generated when the control unit detects a mismatch between the output signals of clutch pedal potentiometer (B65). The voltage at channel 1 (lead 6114) must be double the voltage of channel 2 (lead 6007).

EPC 524173.03 — B65 Clutch Pedal Potentiometer, Voltage at Channel 1 Too High
This diagnostic trouble code is generated when the control unit measures a voltage of more than 4.7 volts at the signal input from channel 1 of the potentiometer (B65, lead 6114). This indicates a problem at the signal lead or at the potentiometer ground connection.

EPC 524173.04 — B65 Clutch Pedal Potentiometer, Voltage at Channel 1 Too Low
This diagnostic trouble code is generated when the control unit measures a voltage of less than 0.3 volts at the signal input from channel 1 of the potentiometer (B65, lead 6114). This indicates a problem at the signal lead or a problem with the potentiometer supply voltage.

EPC 524173.07 — Clutch Pedal Depressed While There is a Fault at the Clutch Pedal Switch
The diagnostic trouble code is generated under the following conditions:
• When the reverse drive lever is in forward or reverse position with clutch pedal potentiometer faulty (diagnostic trouble code EPC 524029.02 active) and the clutch pedal is depressed.
• When the reverse drive lever is in forward or reverse position with clutch pedal potentiometer faulty (diagnostic trouble code EPC 524029.02 active) and the enable pressure sensor (B105) detects a pressure that is lower than the system pressure.

EPC 524230.03 — Y38 Proportional Solenoid Valve for Transmission Enable Stuck in Open Position
The diagnostic trouble code is generated under the following conditions:
• when the enable pressure sensor measures more than 100 kPa (1 bar; 14.5 psi) within 2 seconds after starting the engine, although the proportional solenoid valve (Y38) for transmission enable was not activated.
• when in come home mode or with clutch pedal switch open (clutch pedal fully depressed) the commanded pressure is less than 100 kPa (1 bar; 14.5 psi), and the enable pressure sensor measures a pressure of more than 100 kPa. This indicates a circuit problem at the enable pressure sensor (B105) or a defective proportional solenoid valve for transmission enable (valve stuck open).

EPC 524230.04 — Y38 Proportional Solenoid Valve for Transmission Enable Stuck in Closed Position
The diagnostic trouble code is generated under the following conditions:
• when the enable pressure sensor measures less than 150 kPa (1.5 bar; 22 psi) within 2 seconds after starting the engine, although the proportional solenoid valve (Y38) for transmission enable was activated.
• when in come home mode or with clutch pedal switch closed (clutch pedal not depressed) the commanded pressure is the system pressure, and the enable pressure sensor (B105) measures a pressure of less than 150 kPa. This indicates a circuit problem at the enable pressure sensor (B105) or a defective proportional solenoid valve for transmission enable (valve stuck closed).

EPC 524230.05 — Y38 Proportional Solenoid Valve for Transmission Enable, Fault
The diagnostic trouble code is generated when the control unit detects a circuit problem at the proportional solenoid valve for transmission enable (Y38) when the clutch pedal switch is closed (clutch pedal not depressed) and the solenoid valve is activated. This indicates a circuit problem at the proportional solenoid valve for transmission enable (Y38).

EPC 524234.03 — B105 Sensor for Enable Pressure, Voltage Too High
This diagnostic trouble code is generated when the control unit registers an enable pressure above 2000 kPa (20 bar; 290 psi). This indicates a circuit problem at the enable pressure sensor (B105) or an excessive enable pressure.

EPC 524234.04 — B105 Sensor for Enable Pressure, Voltage Too Low
The diagnostic trouble code is generated when the control unit registers no enable pressure (pressure below 50 kPa; 0.5 bar; 7.3 psi). This indicates a circuit problem at the enable pressure sensor (B105) or an enable pressure that is too low.

EPC 600006.31 — Diagnostic Trouble Code Not Known
This diagnostic trouble code is generated by the CommandCenter (DTI) when the DTI receives an EPC diagnostic trouble code via the CAN BUS that is not stored in the DTI memory. This “general” diagnostic trouble code enables the CommandCenter (DTI) to display information relating to this unknown EPC diagnostic trouble code.