3512C Engines for 785C Off-Highway Trucks with Dynamic Gas Blending Caterpillar

In Cylinder Pressure Is High

Usage:

3512 8BR

Use this procedure to troubleshoot a high in cylinder pressure. Also, use this procedure if one of the following event codes is active or logged.

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Table 1
J1939 Code and Description	CDL Code and Description	Comments
6161-0 Engine Cylinder 1 Pressure : High - most severe (3)	E1801 (3) High Engine Cylinder #1 Pressure	The In Cylinder Pressure Sensor (ICPS) Electronic Control Module (ECM) has detected that engine cylinder pressures are above expected levels.
6161-16 Engine Cylinder 1 Pressure : High - moderate severity (2)	E1801 (2) High Engine Cylinder #1 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6162-0 Engine Cylinder 2 Pressure : High - most severe (3)	E1802 (3) High Engine Cylinder #2 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6162-16 Engine Cylinder 2 Pressure : High - moderate severity (2)	E1802 (2) High Engine Cylinder #2 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6163-0 Engine Cylinder 3 Pressure : High - most severe (3)	E1803 (3) High Engine Cylinder #3 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6163-16 Engine Cylinder 3 Pressure : High - moderate severity (2)	E1803 (2) High Engine Cylinder #3 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6164-0 Engine Cylinder 4 Pressure : High - most severe (3)	E1804 (3) High Engine Cylinder #4 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6164-16 Engine Cylinder 4 Pressure : High - moderate severity (2)	E1804 (2) High Engine Cylinder #4 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6165-0 Engine Cylinder 5 Pressure : High - most severe (3)	E1805 (3) High Engine Cylinder #5 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6165-16 Engine Cylinder 5 Pressure : High - moderate severity (2)	E1805 (2) High Engine Cylinder #5 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6166-0 Engine Cylinder 6 Pressure : High - most severe (3)	E1806 (3) High Engine Cylinder #6 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6166-16 Engine Cylinder 6 Pressure : High - moderate severity (2)	E1806 (2) High Engine Cylinder #6 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6167-0 Engine Cylinder 7 Pressure : High - most severe (3)	E1807 (3) High Engine Cylinder #7 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6167-16 Engine Cylinder 7 Pressure : High - moderate severity (2)	E1807 (2) High Engine Cylinder #7 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6168-0 Engine Cylinder 8 Pressure : High - most severe (3)	E1808 (3) High Engine Cylinder #8 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6168-16 Engine Cylinder 8 Pressure : High - moderate severity (2)	E1808 (2) High Engine Cylinder #8 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6169-0 Engine Cylinder 9 Pressure : High - most severe (3)	E1809 (3) High Engine Cylinder #9 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6169-16 Engine Cylinder 9 Pressure : High - moderate severity (2)	E1809 (2) High Engine Cylinder #9 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6170-0 Engine Cylinder 10 Pressure : High - most severe (3)	E1810 (3) High Engine Cylinder #10 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6170-16 Engine Cylinder 10 Pressure : High - moderate severity (2)	E1810 (2) High Engine Cylinder #10 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6171-0 Engine Cylinder 11 Pressure : High - most severe (3)	E1811 (3) High Engine Cylinder #11 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6171-16 Engine Cylinder 11 Pressure : High - moderate severity (2)	E1811 (2) High Engine Cylinder #11 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6172-0 Engine Cylinder 12 Pressure : High - most severe (3)	E1812 (3) High Engine Cylinder #12 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.
6172-16 Engine Cylinder 12 Pressure : High - moderate severity (2)	E1812 (2) High Engine Cylinder #12 Pressure	The ICPS ECM has detected that engine cylinder pressures are above expected levels.

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Table 2
Associated Codes
J1939 Code	CDL Code	Troubleshooting Procedure
105-0	E539 (3)	Troubleshooting, "Intake Manifold Air Temperature Is High"
105-15	E539 (1)	Troubleshooting, "Intake Manifold Air Temperature Is High"
105-16	E539 (2)	Troubleshooting, "Intake Manifold Air Temperature Is High"
110-0	E361 (3)	Troubleshooting, "Coolant Temperature Is High"
110-15	E361 (1)	Troubleshooting, "Coolant Temperature Is High"
110-16	E361 (2)	Troubleshooting, "Coolant Temperature Is High"
6646-15	E222 (1)	Troubleshooting, "Fuel Pressure Is Low (Gas Supply)"

The In Cylinder Pressure Sensor (ICPS) system provides cylinder health feedback information to the ICPS Electronic Control Module (ECM). The ICPS ECM will take the appropriate action based on the measured level of cylinder pressure. Gas Blending substitution levels will be reduced to lower cylinder pressure for Level 2 events. Level 3 events will disable gas blending for all cylinders. The ICPS replaced the block-mounted detonation sensors that gas engines previously used.

Changes in engine operating conditions and various performance factors will contribute or directly cause pre-ignition and detonation to occur. The engine ECM and sensors monitor a range of pressure and temperatures which can affect engine performance and combustion effectivity.

Probable Causes

Codes
Operator
Air quality
Fuel quality
Boost leaks
Exhaust system
Fuel injectors
Gas admission valve
Deposits or leaks

Recommended Actions

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Table 3
Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect Cat^® Electronic Technician (ET) to the service tool connector. B. Look for active codes that are associated with the system for the event code.	Codes	Result: An associated code is active. Repair: Troubleshoot any associated codes before continuing with this test. Result: A code is active or logged. Proceed to Test Step 2.
2. Interview the Operator A. Determine the type of operation and conditions. B. Determine if any recent changes to the engine or supporting systems have been made. C. Discuss the following: - The time of day in which detonation occurs. - The loads are applied when detonation occurs. - If there has been any changes to fuel supplies.	Operator	Result: No unusual or abnormal activity was found. Engine is under normal, stable operating conditions, and fuel supplies according to the operator. For engines reporting high cylinder pressure on multiple cylinders, proceed to Test Step 3. For engines reporting high cylinder pressure on a single cylinder, proceed to Test Step 5. Result: There are specific times, loads, or conditions that may have contributed to detonation after discussion with the operator. Repair: Determine the best method for site-specific maintenance or operational training to help minimize system changes or fluctuations in fuel quality, load, or operation. If the problem is not resolved, proceed to Test Step 3.
3. Check the Quality of the Inlet Air and Gaseous Fuel A. Check for combustible gases in the surrounding atmosphere. B. Inspect the Liquid Natural Gas (LNG) tank and lines for external leaks. C. Check for proper operation of starting aids (if equipped). D. Obtain a gaseous fuel analysis of the LNG supplied to the LNG tank. Verify the methane number content of the fuel is acceptable for Cat product requirements. Note: An external leak may allow for fuel to enter the engine intake and create an incorrect air/fuel ratio. Also, check for plugged air filters or boost leaks that would lead to an incorrect air/fuel ratio.	Air Quality	Result: The atmosphere does not have combustible gases. Proceed to Test Step 4. Result: The atmosphere has combustible gases. Repair: Do not operate the engine in an environment with combustible gases. Repair or replace damaged components. If the problem is not resolved, proceed to Test Step 4.
4. Inspect the Exhaust System A. Turn the keyswitch to the OFF position. B. Inspect the following exhaust components: - Lines - Hoses - Bellows - Clamps - Exhausts manifolds Note: Verify that all the bellows have the correct orientation. Ensure that the arrow on the bellows is pointing in the direction of the exhaust flow.	Exhaust System	Result: The exhaust system is OK. Proceed to Test Step 5. Result: The exhaust system is NOT OK. Repair: Repair or replace damaged exhaust components. If the problem is not resolved, proceed to Test Step 5.
5. Check the Valve Lash Note: The valve lash can affect the performance of the engine.	Valve Lash	Result: The valve lash is OK. Proceed to Test Step 6. Result: The valve lash is NOT OK. Repair: Reset the valve lash. Refer to Testing and Adjusting, "Valve Lash - Adjust" for additional information. If the problem is not resolved, proceed to Test Step 6.
6. Test the Fuel Injectors A. With the engine running, look for black smoke from the exhaust. If black smoke present, use the cylinder cutout test to disable the faulted cylinders injector. B. Connect Cat ET. C. Use Cat ET to perform the following fuel injector test: - "Cylinder Cutout Test"	Fuel Injectors	Result: Black smoke was not observed. The injector is not over fueling. Proceed to Test Step 7. Result: Black smoke was observed. The injector is over fueling. Repair: Replace the fuel injector(s). Refer to "Troubleshooting", "Injector Trim File - Install" and "Troubleshooting", "Injector Solenoid - Test" for additional information. If the problem is not resolved, proceed to Test Step 7.
7. Test the Gas Admission Valve (GAV) A. Connect Cat ET. B. Use Cat ET to perform the following override: - GAV override	GAV	Result: The GAVs are working. Proceed to Test Step 8. Result: One or more GAVs are not working. Repair: Replace the failed GAV(s). If the problem is not resolved, proceed to Test Step 8. Result: The GAVs are working, but still have a high cylinder pressure. Repair: Replace the failed GAV on the cylinder with high-pressure. If the problem is not resolved, proceed to Test Step 8.
8. Check for Heavy Buildup of Deposits in the Cylinder or Internal Oil Leaks A. Use a borescope to inspect the cylinders. Look for the following conditions: - Deposits on the valve seats - Deposits on the valve faces - Deposits on the cylinder walls that are above the upper limit of the piston stroke - Signs of internal oil leaks Note: Carbon build-up hotspots can ignite the air/fuel mixture prematurely.	Deposits and Leaks	Result: The cylinder check is NOT OK. Repair: Repair or replace damaged components. Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).