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

The In Cylinder Pressure Sensor (ICPS) Electronic Control Module (ECM) software will calculate the expected cylinder pressure behavior during compression based on sensor feedback and the volume of the cylinder. When the sensor signal feedback is indicating behavior during compression that is abnormal, an out of calibration diagnostic is activated.

Note: Use caution when disconnecting the Hirschmann connector from the ICPS. Do not remove connector by pulling on the adapter harness. Use a flat head screwdriver or crows foot tool to apply pressure to the connector base to help with removing the harness connector from the ICPS.

Table 1

J1939 Code and Description	CDL Code and Description	Comments
6161-13 Engine Cylinder 1 Pressure : Out of Calibration	4805-13 Engine Cylinder #1 Pressure Sensor : Out of Calibration	The code is persistently active until the In Cylinder Pressure Sensor (ICPS) Electronic Control Module (ECM) detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6162-13 Engine Cylinder 2 Pressure : Out of Calibration	4806-13 Engine Cylinder #2 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6163-13 Engine Cylinder 3 Pressure : Out of Calibration	4807-13 Engine Cylinder #3 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6164-13 Engine Cylinder 4 Pressure : Out of Calibration	4808-13 Engine Cylinder #4 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6165-13 Engine Cylinder 5 Pressure : Out of Calibration	4809-13 Engine Cylinder #5 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6166-13 Engine Cylinder 6 Pressure : Out of Calibration	4810-13 Engine Cylinder #6 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6167-13 Engine Cylinder 7 Pressure : Out of Calibration	4811-13 Engine Cylinder #7 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6168-13 Engine Cylinder 8 Pressure : Out of Calibration	4812-13 Engine Cylinder #8 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6169-13 Engine Cylinder 9 Pressure : Out of Calibration	4813-13 Engine Cylinder #9 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6170-13 Engine Cylinder 10 Pressure : Out of Calibration	4814-13 Engine Cylinder #10 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6171-13 Engine Cylinder 11 Pressure : Out of Calibration	4815-13 Engine Cylinder #11 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.
6172-13 Engine Cylinder 12 Pressure : Out of Calibration	4816-13 Engine Cylinder #12 Pressure Sensor : Out of Calibration	The code is persistently active until the ICPS ECM detects conditions which are no longer abnormal. The code is logged once returned to a normal circuit health or operating condition.

Table 2

Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect Cat® Electronic Technician (ET) to the service tool connector. B. Determine if a code is active or logged on the In Cylinder Pressure Sensor (ICPS) Electronic Control Module (ECM).	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. Check the Torque of the ICPS Sensor A. Turn the keyswitch to the OFF position. B. Disconnect the ICPS adapter harness from the pressure sensor. C. Check the ICPS torque value. Note: Low sensor torque may allow leakage and lower than expected cylinder pressures.	Torque	Result: The sensor was torqued to 11.5 ± 1 N·m (102 ± 9 lb in). Proceed to Test Step 3. Result: The sensor was not torqued to 11.5 ± 1 N·m (102 ± 9 lb in). Repair: Torque the sensor to 11.5 ± 1 N·m (102 ± 9 lb in). If the problem is not resolved, proceed to Test Step 3.
3. Check the Torque of the Fuel Injector Hold Down Bolt A. Turn the keyswitch to the OFF position. B. Check the torque on the fuel injector hold down bolt.	Torque	Result: The hold down bolt was torqued to 65 ± 7 N·m (48 ± 5 lb ft). Proceed to Test Step 4. Result: The hold down bolt was not torqued to 65 ± 7 N·m (48 ± 5 lb ft). Repair: Remove and inspect the fuel injector O-rings and seals. Refer to Disassembly and Assembly, Electronic Unit Injector-Install for additional information. After the repair, start the engine and run the engine at high idle. If the problem is not resolved, proceed to Test Step 4.
4. Check ICPS Cylinder Head Bore A. Turn the keyswitch to the OFF position. B. Disconnect the ICPS adapter harness from the pressure sensor. C. Remove ICPS from the cylinder head. D. Inspect and clean ICPS bore and sensor seat for debris. E. Reinstall the ICPS and torque to 11.5 ± 1 N·m (102 ± 9 lb in). F. Reconnect the ICPS adapter harness. G. Start the engine. Run the engine at high idle H. Connect Cat ET. J. Use Cat ET to look for the following: - Codes	Cylinder Head	Result: A -13 code is not active. Return the service. Result: A -13 code is active. Proceed to Test Step 5.
5. Swap ICPS with another Known Good ICPS A. Turn the keyswitch to the OFF position. B. Disconnect the ICPS adapter harness from the pressure sensor. Note: Use caution removing and installing ICPS not to introduce debris into the good sensor. C. Remove ICPS from the cylinder head. D. Swap the affected ICPS with a known good ICPS.	Sensor	Result: A -13 code is not active on the cylinder that had the original code with a known good sensor installed. Repair: Replace the ICPS. Verify that the repair eliminated the problem. Result: A -13 code remained active with a known good sensor installed. Repair: There is a mechanical issue with the cylinder resulting in low cylinder pressure. Further inspection of the mechanical systems may be required. 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).