87121-ZV3-000 Honda MARK, RR. (Honda Code 3705316).

Table 1
Event Code
CDL Description Conditions which Generate this Code System Response
E2112(1) Low Engine Coolant Pressure The engine coolant pressure is below the map-based trip point pressure for the programmed delay time. The code is logged. Probable Causes
Low coolant level
Damaged coolant lines
Radiator blockage
Blockage of the oil cooler heat exchanger
Engine coolant pump outlet pressure sensor
Jacket water coolant pumpRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Product Status Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. Determine if the diagnostic trouble code that directed to this procedure is present.
D. Look for active diagnostic codes that are associated with the system for the event code that directed to this procedure.
E2112
Result: An associated code is present.
Repair: Troubleshoot any associated codes before continuing with this test.
Result: An E2112 code is present.
Proceed to the next step.
Result: No active codes
STOP
2. Check for Low Coolant Level
Level
Result: Coolant level is OK.
Proceed to the next step.
Result: Coolant level is NOT OK.
Repair: Add coolant.
If the problem is not resolved, proceed to the next step.
3. Check for Damaged Cooling System Piping
A. Inspect the piping for the following conditions:
- Damage
- Crushing
- Bending
B. Inspect the rubber boots: Look for signs of cracking, and collapse.
Damage
Result: The system piping is OK.
Proceed to the next step.
Result: The system piping is NOT OK.
Repair: Repair or replace any damaged piping or boots.
If the problem is not resolved, proceed to the next step.
4. Inspect the Radiator for Blockage
A. Check the radiator for internal blockage.
B. Check the temperature difference between the inlet and the outlet of the radiator.
Blockage
Result: The radiator is OK.
Proceed to the next step.
Result: The radiator is NOT OK.
Repair: Clean the radiator or perform the necessary repairs.
If the problem is not resolved, proceed to the next step.
5. Check if the Oil Cooler has a Blockage
A. Inspect the inlet side of oil cooler for debris and blockage.
Blockage
Result: The oil cooler is OK.
Proceed to the next step.
Result: The oil cooler is NOT OK.
Repair: Clean the oil cooler or perform the necessary repairs.
If the problem is not resolved, proceed to the next step.
Steam or hot coolant can cause severe burns.Do not loosen the filler cap or the pressure cap on a hot engine.Allow the engine to cool before removing the filler cap or the pressure cap.
Table 3
Troubleshooting Test Steps Values Results
6. Check the Engine Coolant Pump Outlet Pressure Sensor
A. While the engine is off and the cooling system is cool, remove any pressure from the system by carefully removing the pressure cap. While there is no pressure in the cooling system, use Cat ET to check the status of the "Engine Coolant Pump Outlet Pressure (Absolute)" parameter.
B. Compare the "Engine Coolant Pump Outlet Pressure (Absolute)" to the status of the "Atmospheric Pressure" parameter. "Engine Coolant Pump Outlet Pressure (Absolute)"
Sensor
Result: For sensors that are working correctly, the pressures will be comparable. The sensor is OK.
Proceed to the next step.
Result: The sensor is NOT OK.
Repair: Replace the damaged components. Refer to the Disassembly and Assembly manual.
If the problem is not resolved, proceed to the next step.
7. Install a Mechanical Gauge to Verify the Coolant Pressure
A. Install a mechanical gauge near the coolant pressure sensor.
B. Use the gauge to verify that a low coolant pressure exists.
Mechanical Gauge
Result: The mechanical gauge does not confirm that the coolant pressure is low.
Troubleshoot the circuit for the coolant pressure sensor.
Verify that any repairs resolve the original fault.
Result: The mechanical gauge confirms that the coolant pressure is low.
Perform the following checks:
- Check the water temperature regulators for proper operation.
- Check for a plugged heat exchanger.
- Inspect the coolant pump for damage to the impeller.
Repair: Perform any necessary repairs.
8. Inspect the Jacket Water Coolant Pump
A. Inspect the impeller vanes.
Pump
Result: The pump is OK.
Result: The pump is NOT OK.
Repair: Repair impeller vanes. Replace parts, if necessary. Refer to the engine Disassembly and Assembly manual for details.