The Injection Control Pressure Regulation System (IPR_SYS) consists of the low pressure oil lubrication system, passages in the front cover and reservoir, high pressure oil pump, high pressure oil line, as well as the high pressure oil rail that is mounted on the side of the cylinder head. The system also includes the injectors and their sealing O-rings, the IPR valve and the ICP sensor (Injection Control Pressure) and associated wiring. For an exploded view of the IPR_SYS, see Figure
“Injection Pressure Regulation System”
.
Figure 1. Injection Pressure Regulation System
Section 34.1.1
System Functions
The function of the IPR_SYS is to develop, maintain and control the high pressure injection control pressure to provide the force to actuate the injectors and provide fuel to the engine.
Section 34.1.2
Fault Detection / Management
The fault codes associated with this system may indicate an electrical or electronic control system failure, but most likely will indicate a mechanical or hydraulic problem with the IPR_SYS.
The ECM constantly monitors the ICP in the system to assure the control system is providing the proper control pressure at all times. If the oil pressure feedback provided by the ICP sensor does not meet the programmed desired values of the ECM, the ECM will set a fault code. It will also illuminate the WARN lamp and control the operation of the injection control system by calculating the correct oil pressure for all engine operating conditions until the system is diagnosed and repaired.
The ECM also monitors the ICP developed while cranking the engine. If pressure does not develop within the expected time limit of the ECM, it will set an appropriate fault code that will aid the technician in diagnosing the no start or hard start condition.
The Electronic Service Tool (EST) may be used by the technician to command the ECM to perform an engine running test on the ICP system. The ECM controls the pressure regulator in a programmed sequence to evaluate system performance. At the end of the test, the ECM will transmit any fault codes if system performance is unsatisfactory.
Section 34.1.3
ECM Diagnostics
The following flash codes could display when troubleshooting the IPR_SYS:
Section 34.1.3.1
Flash Code 333
ATA Code PID 164 FMI 10
ICP above/below desired level.
Flash Code 333 may be set during normal engine operation through the continuous monitor function or during the Engine Running Standard Test. It indicates that the measured pressure does not match the pressure value that the ECM expects. Flash Code 333 will be set if the measured value is greater or less than 362 psi (2.5 MPA) of desired injection control pressure for a period greater than seven seconds. When this code is active, the ECM will ignore feedback from the ICP sensor and control the IPR valve to control the pressure in the system from pre-programmed default values. When this occurs, it will illuminate the engine WARN lamp to notify the driver.
Flash Code 333 is usually associated with poor engine performance. Symptoms are slow acceleration time, low power at full load, and possible engine under run.
Possible Causes:
- Low oil level, contaminated or aerated engine oil.
- Trapped air in the ICP system, particularly after an injector or high pressure pump replacement.
- Defective or stuck injection pressure regulator.
- Intermittent IPR valve wiring connection. Spread IPR harness terminals at valve, poorly crimped terminals or pulled back pins.
- Leaking injector O-rings.
- Problem with ICP sensor and sensor circuit; system biased high or low.
Recommended actions are listed in Table
“Recommended Actions”
.
| Test | Comments |
| Check repair history – Determine if air entrapment could be caused by ICP system disassembly. | If system was disassembled, ensure vehicle is operated 15 to 20 miles after injection control system has been serviced. |
| Check oil level and quality. | Check for level and contamination and correct API classification. |
| Check active and inactive faults. | Repair any ICP sensor codes first. |
| Perform a Key ON Engine OFF Standard Test. | Test will verify IPR valve circuit continuity. |
| Perform a Key ON Engine Running Test. | ICP step test will verify a gross ICP system failure. |
| Perform Engine Running wiggle test, Intermittent fault detection test. | When engine is running enable test, pull/wiggle wires on ICP sensor and IPR valve as well as all pass through connectors. If fault is set or engine dies, inspect wires at point of connection; check codes. |
| Perform ICP Pressure Test – Performance Diagnostic Form (Oil aeration). | Will verify oil is aerated at high idle, Step #9 on the Performance Diagnostic Form. |
| Test high pressure (ICP system) for leaks. | For ICP Leakage Tests, refer to “10.15.3 ICP Leakage Test”
. |
Section 34.1.3.2
Flash Code 334
ATA Code PID 164 FMI 7
ICP unable to reach set point — poor performance.
The purpose of Flash Code 334 is to determine if a rapid increase in ICP can be developed when commanded by the operator while the engine is running.
Flash Code 334 is an ICP system response time fault that compares measured injection control pressure to desired injection control pressure, and looks for a large pressure difference- 1300 psi (9 MPA) for a short period of time (three seconds). Its primary function is to detect injection control pressure system faults.
When this code is active, the engine warning lamp will illuminate and the ECM will ignore the ICP sensor and control IPR valve operation from pre-programmed default values.
An active Flash Code 334 is usually associated with poor engine performance conditions, including slow time to acceleration and lower power concerns.
Possible Causes:
- Low oil level, contaminated or aerated engine oil.
- Trapped air in the ICP system, particularly after an injector or high pressure pump replacement.
- Defective or stuck injection pressure regulator.
- Intermittent IPR valve wiring connection. Spread IPR harness terminals at valve, poorly crimped terminals or pulled back pins.
- Leaking injector O-rings.
- Problem with ICP sensor and sensor circuit; system biased high or low.
Recommended actions are listed in Table
“Recommended Actions”
.
| Test | Comments |
| Check repair history – Determine if air entrapment could be caused by ICP system disassembly. | If system was disassembled, ensure vehicle is operated 15 to 20 miles after injection control system has been serviced. |
| Check oil level and quality. | Check for level and contamination and correct API classification. |
| Check active and inactive faults. | Repair any ICP sensor codes first. |
| Perform a Key ON Engine OFF Standard Test. | Test will verify IPR valve circuit continuity. |
| Perform a Key ON Engine Running Test. | ICP step test will verify a gross ICP system failure. |
| Perform Engine Running wiggle test, Intermittent fault detection test. | When engine is running enable test, pull/wiggle wires on ICP sensor and IPR valve as well as all pass through connectors. If fault is set or engine dies, inspect wires at point of connection; check codes. |
| Perform ICP Pressure Test – Performance Diagnostic Form (Oil aeration). | Will verify oil is aerated at high idle, Step #9 on the Performance Diagnostic Form. |
| Test high pressure (ICP system) for leaks. | For ICP Leakage Tests, refer to “10.15.3 ICP Leakage Test”
. |
Section 34.1.3.3
Flash Code 331
ATA Code PID 164 FMI 10
ICP above working system range.
The purpose of Flash Code 331 is to detect when the ICP is above its normal working range (3675 psi or 25 MPA). This code may indicate a mechanical injection control pressure system problem or a wiring or ICP sensor problem. When this code is set, the engine warning lamp is illuminated and the ECM ignores the ICP sensor signal and uses estimated ICP values to operate the engine.
Note: If the engine still performs well when this code is set, the problem is more likely in the ICP sensor circuit.
Possible Causes:
- Contaminated or improper grade of engine oil.
- Defective or stuck injection pressure regulator (IPR) valve.
- Improperly matched parts (IPR valve, high pressure pump, front cover).
- Grounded IPR control wire.
- Problems with ICP sensor or circuit causing signal to be biased high.
Section 34.1.3.4
Flash Code 335
ATA Code PID 164 FMI 1
ICP unable to build pressure during cranking.
The purpose of Flash Code 335 is to determine if injection control pressure is being developed during engine cranking. It is an ICP system check and will be set after 8 to 10 seconds of engine cranking time with less than 725 psi (5 MPA) of injection control pressure detected. The period of engine cranking time before Fault Code 335 is set varies with engine temperature. Engine cranking speed must be greater than 130 r/min before fault detection begins.
An active Flash Code 335 is normally associated with a long time to start or no start engine condition.
Possible Causes:
- No oil or insufficient oil in the engine.
- Air in the injection control pressure system, particularly after an injector or high pressure pump replacement.
- Defective or stuck injection pressure regulator.
- Leaking injector O-rings.
- Loose high pressure pump gear.
- Defective high pressure pump.
Recommended actions are listed in Table
“Recommended Actions”
.
| Test | Comments |
| Visual inspection | Check to see if IPR regulator and ICP sensor wiring is connected; check for oil leaks; check to see if injection control system recently disassembled (air entrapment); ensure vehicle is operated a minimum of 15 to 20 miles if symptom is hard start and evidence of recent disassembly of injection control system. |
| Check oil level, quality, pressure | Check for level and contamination; check for oil in the oil reservoir; verify lube oil pressure during engine cranking. |
| Check active and inactive faults. | Repair any ICP and CMP sensor codes first. |
| Perform a Key ON Engine OFF Standard Test. | Test will verify IPR valve circuit continuity. |
| Perform Engine Running wiggle test, Intermittent fault detection test. — Hard Start Only. | When engine is running enable test, pull/wiggle wires on ICP sensor and IPR valve as well as all pass through connectors. If fault is set or engine dies, inspect wires at point of connection; check codes. |
| Perform ICP Pressure Test – Hard Start/No Start Diagnostic Form. | Will verify oil is aerated at high idle, Step #9 on the Performance Diagnostic Form. |
| Test high pressure (ICP system) for leaks. | For ICP Leakage Tests, refer to “10.15.3 ICP Leakage Test”
. |
| Series 40E Troubleshooting Manual – 6SE241 |
| Generated on 10-13-2008 |