Understanding Bosch Diesel Electronic Fuel Injection High-Pressure Common Rail System Fault Codes

The Bosch Diesel Electronic Fuel Injection (EFI) High-Pressure Common Rail (CR) system is an essential component in modern diesel engines, ensuring optimal fuel delivery and engine performance. As with all mechanical systems, the fuel injectors in these systems will eventually wear out, and some faults may arise during use. While most of these issues are minor, error codes related to the system can be confusing for those unfamiliar with the technology. Without a solid understanding of the Bosch EFI High-Pressure Common Rail system, even small problems can lead to unnecessary downtime.

In this blog, we will explore the common fault codes found in Bosch diesel systems.

0 Exhaust brake valve feedback does not match ECU control command
P0016 Phase sensor and crankshaft sensor relative position deviation
P0045 Turbocharger actuator control line open circuit
P0046 Turbocharger actuator control line ECU internal driver module overheating
P0047 Turbocharger actuator control line short circuit to ground
P0048 Turbocharger actuator control line short circuit to high voltage
P0069 Boost pressure sensor drift
P0071 Invalid environmental temperature sensor signal from CAN
P0072 Ambient temperature sensor output voltage below the lower limit (wire shorted to ground)
P0073 Ambient temperature sensor output voltage above the upper limit (wire open or shorted to high voltage)
P0087 Fuel pressure below the minimum limit
P0088 Fuel pressure above the maximum limit
P0097 Intake air temperature sensor voltage too low (wire shorted to ground)
P0098 Intake air temperature sensor voltage too high (wire open or shorted to high voltage)
P0100 The uncorrected air mass flow signal measured by the airflow meter is too high or too low (wire open or shorted)
P0101 The corrected air mass flow signal measured by the airflow meter is too high or too low
P0102 Negative drift of the air mass flow meter
P0103 Positive drift of the air mass flow meter
P0104 Zero-point drift of the air mass flow meter
P0110 Additional air temperature sensor on the air mass flow meter has a wiring short circuit or open circuit
P0112 Additional air temperature sensor on the air mass flow meter detects a temperature that is too low
P0113 Additional air temperature sensor on the air mass flow meter detects a temperature that is too high
P0115 Invalid coolant temperature signal received via CAN
P0116 Unreliable dynamic characteristics of the coolant temperature sensor
P0117 Coolant temperature sensor output voltage below the lower limit (wire shorted to ground)
P0118 Coolant temperature sensor output voltage above the upper limit (wire open or shorted to high voltage)
P0122 Throttle pedal potentiometer 1 output voltage below the lower limit
P0123 Throttle pedal potentiometer 1 output voltage above the upper limit
P0128 Unreliable static characteristics of the coolant temperature sensor
P0182 Fuel temperature sensor output voltage too low (wire shorted to ground)
P0183 Fuel temperature sensor output voltage too high (wire open or shorted to high voltage)
P0191 Excessive positive drift of the rail pressure sensor
P0192 Rail pressure sensor output voltage below the lower limit (wire shorted to ground)
P0193 Rail pressure sensor output voltage above the upper limit (wire open or shorted to high voltage)
P0194 Excessive negative drift of the rail pressure sensor
P0195 Invalid oil temperature signal received via CAN
P0197 Oil temperature sensor output voltage below the lower limit
P0198 Oil temperature sensor output voltage above the upper limit
P0201 Cylinder 1 injector open circuit
P0202 Cylinder 2 injector open circuit
P0203 Cylinder 3 injector open circuit
P0204 Cylinder 4 injector open circuit
P0205 Cylinder 5 injector open circuit
P0206 Cylinder 6 injector open circuit
P0222 Throttle pedal potentiometer 2 output voltage below the lower limit
P0223 Throttle pedal potentiometer 2 output voltage above the upper limit
P0234 Actual boost pressure significantly exceeds the control target
P0235 Invalid boost pressure signal received via CAN
P0237 Boost pressure sensor output voltage below the lower limit (wire shorted to ground)
P0238 Boost pressure sensor output voltage above the upper limit (wire open or shorted to high voltage)
P0251 Fuel metering unit control line open circuit
P0252 Fuel metering unit ECU internal driver circuit overheating
P0253 Fuel metering unit control line shorted to ground
P0254 Fuel metering unit control line shorted to high voltage
P025C Not in use
P025D Not in use
P0261 Cylinder 1 injector low-end shorted to high-end
P0262 Cylinder 1 injector low-end shorted to high voltage
P0263 Cylinder 1 injector other errors
P0264 Cylinder 2 injector low-end shorted to high-end
P0265 Cylinder 2 injector low-end shorted to high voltage
P0266 Cylinder 2 injector other errors
P0267 Cylinder 3 injector low-end shorted to high-end
P0268 Cylinder 3 injector low-end shorted to high voltage
P0269 Cylinder 3 injector other errors
P0270 Cylinder 4 injector low-end shorted to high-end
P0271 Cylinder 4 injector low-end shorted to high voltage
P0272 Cylinder 4 injector other errors
P0273 Cylinder 5 injector low-end shorted to high-end
P0274 Cylinder 5 injector low-end shorted to high voltage
P0275 Cylinder 5 injector other errors
P0276 Cylinder 6 injector low-end shorted to high-end
P0277 Cylinder 6 injector low-end shorted to high voltage
P0278 Cylinder 6 injector other errors
P0299 Actual boost pressure significantly lower than the control target
P0300 Multiple cylinder misfire
P0301 Cylinder 1 misfire
P0302 Cylinder 2 misfire
P0303 Cylinder 3 misfire
P0304 Cylinder 4 misfire
P0305 Cylinder 5 misfire
P0306 Cylinder 6 misfire
P0335 No crankshaft sensor signal
P0336 Incorrect crankshaft sensor signal
P0340 No camshaft sensor signal
P0341 Incorrect camshaft sensor signal
P0380 ECU does not request glow plug operation, but the glow plug is active
P0382 ECU requests glow plug operation, but the glow plug is not active
P0383 ECU control line to the glow plug is shorted to ground
P0384 ECU control line to the glow plug is shorted to high voltage
P0401 Actual fresh air intake exceeds the target intake set by the EGR system
P0402 Actual fresh air intake is less than the target intake set by the EGR system
P0403 EGR valve actuator control line ECU internal driver module overheating
P0404 EGR valve actuator control line open circuit
P0405 EGR valve position sensor voltage below the lower limit (wire shorted to ground)
P0406 EGR valve position sensor voltage above the upper limit (wire open or shorted to high voltage)
P0475 Exhaust brake valve control line open circuit
P0476 Exhaust brake valve ECU internal driver module
P0477 Exhaust brake valve control line shorted to ground
P0478 Exhaust brake valve control line shorted to high voltage
P0480 ECU control line to fan 1 open circuit
P0481 ECU control line to fan 2 open circuit
P0483 ECU internal driver module for fan 1 control line overheating
P0484 ECU internal driver module for fan 2 control line overheating
P0487 Throttle actuator control line open circuit
P0488 Throttle actuator ECU internal driver module overheating
P0489 EGR valve actuator control line shorted to ground
P0490 EGR valve actuator control line shorted to high voltage
P0500 Vehicle speed sensor hardware error
P0501 Vehicle speed sensor signal unreliable
P0503 Vehicle speed sensor exceeds maximum value
P0504 Main and secondary brake pedal signal comparison is unreliable
P0513 Mismatch between sent and received anti-theft signals
P0520 Engine oil pressure signal from CAN is invalid
P0521 Engine oil pressure is too high and unreliable
P0522 Engine oil pressure sensor output voltage is below the lower limit (wire shorted to ground)
P0523 Engine oil pressure sensor output voltage is above the upper limit (wire open or shorted to high voltage)
P0524 Engine oil pressure is too low and unreliable
P0530 ECU internal receiving circuit failure for duty-cycle-based air conditioning pressure signal
P0531 Duty-cycle-based air conditioning pressure signal exceeds the upper or lower limit or enters a special fault mode
P0532 Duty cycle of the air conditioning pressure signal is below the lower limit
P0533 Duty cycle of the air conditioning pressure signal exceeds the upper limit
P0562 Battery voltage is too low
P0563 Battery voltage is too high
P0571 Brake pedal signal transmitted via CAN is unreliable
P0575 Cruise control request is unreliable
P0607 ECU internal control chip error
P060A Communication failure in ECU internal CJ940 chip
P060B ECU internal analog-to-digital conversion module fault
P060C ECU internal watchdog chip error
P0611 Injection count is restricted
P0615 ECU starter motor control wire open circuit or driver module overheating
P0616 ECU starter motor control wire shorted to ground
P0617 ECU starter motor control wire shorted to high voltage
P0627 Fuel pre-supply pump control wire open circuit
P0628 Fuel pre-supply pump control wire shorted to ground
P0629 Fuel pre-supply pump control wire shorted to high voltage
P062A ECU internal output module for fuel pre-supply pump overheating
P062B Injector driver chip fault
P062F ECU internal EEPROM read/write error
P0638 Throttle valve feedback signal does not match ECU control request
P0642 Sensor power supply voltage 1 too low
P0643 Sensor power supply voltage 1 too high
P0645 ECU air conditioning control wire open circuit or ECU internal driver module overheating
P0646 ECU air conditioning control wire shorted to ground
P0647 ECU air conditioning control wire shorted to high voltage
P0650 ECU OBD fault indicator output wire fault (short circuit, open circuit)
P0652 Sensor power supply voltage 2 too low
P0653 Sensor power supply voltage 2 too high
P0660 Variable swirl ratio actuator control wire open circuit
P0661 Variable swirl ratio actuator control wire shorted to ground
P0662 Variable swirl ratio actuator control wire shorted to high voltage
P0670 ECU control wire for glow plug open circuit or its driver module overheating
P0686 Main relay opens too early
P0687 Main relay opens too late
P0691 ECU control wire for fan 1 shorted to ground
P0692 ECU control wire for fan 1 shorted to high voltage
P0693 ECU control wire for fan 2 shorted to ground
P0694 ECU control wire for fan 2 shorted to high voltage
P0698 Sensor power supply voltage 3 too low
P0699 Sensor power supply voltage 3 too high
P0704 Clutch signal not reliable
P0856 Not in use
P1007 Not in use
P100D Oil temperature and coolant temperature comparison not reliable
P1011 Rail pressure controller positive deviation exceeds upper limit
P1012 Rail pressure controller positive deviation severely exceeds upper limit
P1013 Rail pressure controller negative deviation lower than lower limit
P1014 Fuel pressure value not reliable during engine overrun
P1100 Air mass flow meter software correction too large
P1101 Air mass flow meter additional air temperature sensor’s analog output voltage too high or too low
P1102 Air mass flow meter additional air temperature sensor’s duty cycle output signal too high or too low
P1103 Coolant temperature and oil temperature sensor signal comparison not reliable
P1106 Air mass flow meter additional air temperature sensor’s duty cycle output signal period too high
P1107 Air mass flow meter additional air temperature sensor’s duty cycle output signal period too low
P1109 Not in use
P110A Not in use
P110B Not in use
P110C Not in use
P1112 Coolant temperature relative to air mass flow meter’s temperature sensor reliability check error
P1200 Injector 1 positive correction value too high
P1201 Injector 1 negative correction value too high
P1202 Injector 2 positive correction value too high
P1203 Injector 2 negative correction value too high
P1204 Injector 3 positive correction value too high
P1205 Injector 3 negative correction value too high
P1206 Injector 4 positive correction value too high
P1207 Injector 4 negative correction value too high
P1208 Injector 5 positive correction value too high
P1209 Injector 5 negative correction value too high
P120A Injector 6 positive correction value too high
P120B Injector 6 negative correction value too high
P120C Injector 1 dynamic positive correction value too high
P120D Injector 1 dynamic negative correction value too high
P120E Injector 2 dynamic positive correction value too high
P120F Injector 2 dynamic negative correction value too high
P1210 Injector 3 dynamic positive correction value too high
P1211 Injector 3 dynamic negative correction value too high
P1212 Injector 4 dynamic positive correction value too high
P1213 Injector 4 dynamic negative correction value too high
P1214 Injector 5 dynamic positive correction value too high
P1215 Injector 5 dynamic negative correction value too high
P1216 Injector 6 dynamic positive correction value too high
P1217 Injector 6 dynamic negative correction value too high
P1223 Injector high-end short circuit
P1224 Injector low-end short circuit to ground
P1225 Injector other error
P1226 Injector other error
P1227 Injector other error
P1228 Injector other error
P1229 Injector open circuit
P122A Injector other error
P122B Injector high-end short circuit (not in use, only for 6-cylinder engines)
P122C Injector low-end short circuit to ground (not in use, only for 6-cylinder engines)
P122D Injector other error (not in use, only for 6-cylinder engines)
P122E Injector other error (not in use, only for 6-cylinder engines)
P122F Injector other error (not in use, only for 6-cylinder engines)
P1230 Injector other error (not in use, only for 6-cylinder engines)
P1231 Injector open circuit (not in use, only for 6-cylinder engines)
P1232 Injector other error (not in use, only for 6-cylinder engines)
P1233 Injector other error for cylinder 1
P1234 Injector other error for cylinder 1
P1235 Injector other error for cylinder 1
P1236 Injector other error for cylinder 2
P1237 Injector other error for cylinder 2
P1238 Injector other error for cylinder 2
P1239 Injector other error for cylinder 3
P123A Injector other error for cylinder 3
P123B Injector other error for cylinder 3
P123C Injector other error for cylinder 4
P123D Injector other error for cylinder 4
P123E Injector other error for cylinder 4
P123F Injector other error for cylinder 5
P1240 Injector other error for cylinder 5
P1241 Injector other error for cylinder 5
P1242 Injector other error for cylinder 6
P1243 Injector other error for cylinder 6
P1244 Injector other error for cylinder 6
P12FF Not in use
P1301 Not in use
P1562 Airflow meter supply voltage too high or too low
P1601 ECU to dashboard coolant temperature output line shorted to high level
P1602 ECU to dashboard coolant temperature output line shorted to ground
P1603 ECU to dashboard coolant temperature output line open circuit
P1604 ECU to dashboard coolant temperature output internal driver module overheat
P1605 ECU to dashboard engine speed output line shorted to high level
P1606 ECU to dashboard engine speed output line shorted to ground
P1607 ECU to dashboard engine speed output line open circuit
P1608 ECU to dashboard preheating light output line shorted to high level
P1609 ECU to dashboard preheating light output line shorted to ground
P160A ECU to dashboard preheating light output line open circuit
P160B ECU to dashboard preheating light output line driver module overheat
P160C ECU internal analog-to-digital conversion module failure
P1613 Anti-runaway monitor detected excessive power-on time
P1614 Anti-runaway monitor detected unreliable engine speed
P1615 Not in use
P1616 Watchdog error cannot shut down
P1617 Internal supply voltage too high error cannot shut down
P1618 Internal supply voltage too low error cannot shut down
P1619 ECU to system fault light output line shorted to high level
P161A ECU to system fault light output line shorted to ground
P161B ECU to system fault light output line open circuit
P161C ECU to system fault light driver module overheat
P161D Vehicle model data corrupted
P161E Vehicle model data cannot be selected
P161F Not in use
P1620 Variable swirl ratio actuator driver module overheat
P1621 ECU to dashboard fuel consumption rate signal output line shorted to high level
P1622 ECU to dashboard fuel consumption rate signal output line shorted to ground
P1623 ECU to dashboard fuel consumption rate signal output line open circuit
P1624 ECU to dashboard fuel consumption rate signal output driver module overheat
P1625 ECU to exhaust brake display light output line shorted to high level
P1626 ECU to exhaust brake display light output line shorted to ground
P1627 ECU to exhaust brake display light output line open circuit
P1628 ECU to exhaust brake display light output driver module overheat
P1629 Throttle position sensor error
P1630 Software reset
P1631 Not in use
P1637 ECU internal power module voltage too high
P1638 ECU internal power module voltage too low
P1641 Not in use
P2135 Throttle pedal potentiometer 1 and potentiometer 2 comparison not credible
P2141 Throttle actuator control line shorted to ground
P2142 Throttle actuator control line shorted to high level
P2157 Vehicle speed signal from CAN transmission invalid
P2226 Atmospheric pressure sensor signal from CAN transmission invalid
P2228 Atmospheric pressure sensor output voltage too low
P2229 Atmospheric pressure sensor output voltage too high
P2264 Diesel fuel filter water separator water level sensor fault
P2267 Diesel fuel filter water separator water level full
P2299 Both throttle and brake pedals depressed simultaneously
P245A EGR cooler bypass valve actuator control line open
P245B EGR cooler bypass valve actuator control line driver module overheat
P245C EGR cooler bypass valve actuator control line shorted to ground
P245D EGR cooler bypass valve actuator control line shorted to high level
P2517 Analog air conditioning pressure sensor voltage signal below lower limit (short to low level)
P2518 Analog air conditioning pressure sensor voltage signal above upper limit (shorted or short to high level)
P2519 Air conditioning switch signal from CAN transmission invalid
P2530 Shutdown button stuck
P2533 Ignition switch error
U0404 TSC request not credible

Troubleshooting Bosch Diesel EFI High-Pressure Common Rail System Faults

Step 1: Check for Wiring and Connector Issues

Electrical faults are common causes of many injector-related error codes. Begin by inspecting the wiring harnesses and connectors associated with the fuel injectors. Look for signs of wear, corrosion, or loose connections.

Step 2: Reset the ECU

If communication errors are detected, resetting the ECU may help clear temporary faults. Always ensure the vehicle’s battery is disconnected before attempting any ECU reset.

Step 3: Replace Faulty Injectors

If fault codes indicate a persistent problem with one or more injectors, replacement may be necessary. Over time, injectors can become clogged or damaged, leading to poor fuel delivery and engine performance.

Step 4: Perform a Comprehensive Diagnostic

If the issue persists, performing a thorough diagnostic using specialized tools can help identify the root cause. This may involve checking sensor readings, actuator responses, and fuel pressure to ensure all components are functioning correctly.

Conclusion

Understanding and diagnosing fault codes in the Bosch Diesel Electronic Fuel Injection High-Pressure Common Rail system is essential for maintaining optimal engine performance. By familiarizing yourself with common error codes and knowing how to troubleshoot them, you can minimize downtime and reduce repair costs. Always follow manufacturer guidelines and consult a professional mechanic if you’re unsure how to proceed with repairs or diagnostics.

By staying informed and proactive, you ensure that your diesel engine runs smoothly and efficiently for years to come.