24630-ZW5-000ZA Honda SEE PART DETAILS - SUP; LINK, SHIFT *NH8* (Honda Code 5891791). (DARK GRAY)

Note: Severe slopes can cause low oil pressure. If the machine is operated on severe slopes, the oil level in the engine crankcase must be at the "FULL" mark on the dipstick. Refer to the Operation and Maintenance Manual for details.
Table 1
Diagnostic Code for Low Engine Oil Pressure
J1939 Code Code Description Comments
100-1 Engine Oil Pressure : Low - most severe (3) The Electronic Control Module (ECM) detects that the oil pressure is low.
The engine is running.
If equipped, the warning lamp will come on and the oil pressure lamp will come on.
Probable Causes
Engine oil level
Oil specification
Aerated oil
Engine oil pressure
Engine oil filter
Engine oil cooler
Fuel in the engine oil
Piston cooling jets
Engine oil suction tube
Engine oil pump pressure relief valve
Engine oil pump
Bearing clearanceRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 2
Troubleshooting Test Steps Values Results
1. Engine Oil Level
A. Check the engine oil level.
Oil level
Result: The engine oil level is low.
Repair: Fill the oil system to the full mark on the dipstick.
Result: The engine oil level is OK.
Proceed to Test Step 2.
2. Oil Specification
A. Check that engine oil of the correct specification is being used. Refer to the Operation and Maintenance Manual, "Refill Capacities and Recommendations".
Oil specification
Result: An incorrect specification of engine oil is being used.
Repair: Drain the oil system and refill the oil system with engine oil of the correct specification. Refer to Operation and Maintenance Manual, "Engine Oil and Filter - Change".
Result: The engine contains oil of the correct specification.
Proceed to Test Step 3.
3. Aerated Oil
A. Sample the engine oil for aeration.
Note: Foamy oil on the dipstick is a good indication of aeration.
Aeration
Result: The oil is aerated.
Proceed to Test Step 9.
Result: The oil is not aerated.
Proceed to Test Step 4.
4. Engine Oil Pressure
A. Check the actual engine oil pressure with a calibrated test gauge.
The oil pressure switch should not close unless the pressure drops below 72 17 kPa (10.4 2.5 psi).
Oil pressure
Result: The oil pressure reading from the test gauge is greater than the closing pressure for the oil pressure switch.
Repair: Install a new oil pressure switch. Refer to Disassembly and Assembly, "Engine Oil Pressure Sensor - Remove and Install".
Result: The oil pressure reading from the test gauge is less than the closing pressure for the oil pressure switch.
Proceed to Test Step 5.
5. Engine Oil Filter
A. Remove the engine oil filter. Refer to the Operation and Maintenance Manual, "Engine Oil and Filter - Change".
B. Inspect the engine oil filter for evidence of blockage.
Oil filter
Result: The oil filter is blocked.
Repair: Investigate the cause of the filter blockage.
Install a new oil filter. Refer to the Operation and Maintenance Manual, "Engine Oil and Filter - Change" for further information.
Result: The oil filter is OK.
Repair: Install a new oil filter. Refer to the Operation and Maintenance Manual, "Engine Oil and Filter - Change" for further information.
Proceed to Test Step 6.
6. Engine Oil Cooler
A. Check the oil cooler for signs of damage or restrictions.
Oil cooler
Result: The oil cooler has signs of damage or restriction.
Repair: Install a new oil cooler. Refer to Disassembly and Assembly, "Engine Oil Cooler - Remove" and Disassembly and Assembly, "Engine Oil Cooler - Install".
Result: The oil cooler is OK.
Proceed to Test Step 7.
7. Fuel in the Engine Oil
A. Check fuel contamination of the engine oil. Refer to Troubleshooting, "Oil Contains Fuel".
Oil contamination
Result: The oil contains fuel.
Repair: Refer to Troubleshooting, "Oil Contains Fuel".
Result: The oil is not contaminated.
Proceed to Test Step 8.
8. Piston Cooling Jets
A. Inspect the piston cooling jets for cracks, damage, or missing jets.
Piston cooling jets
Result: A piston cooling jet is cracked, damaged, or missing.
Repair: Install a new piston cooling jet. Refer to Disassembly and Assembly, "Piston Cooling Jets - Remove and Install".
Result: The piston cooling jets are OK.
Proceed to Test Step 9.
9. Engine Oil Suction Tube
A. Check the inlet screen on the oil suction tube and remove any material that may be restricting oil flow.
B. Check the joints of the oil suction tube for cracks or a damaged joint.
Note: Cracks or damage may allow air leakage into the supply to the oil pump.
Oil suction tube
Result: The inlet screen on the oil suction tube is blocked with debris.
Repair: Remove the debris from the inlet screen. Attempt to identify the source of the debris.
Result: The oil suction tube is cracked.
Repair: Install a new oil suction tube.
Result: The oil suction tube is OK.
Proceed to Test Step 10.
10. Engine Oil Pump Pressure Relief Valve
A. Inspect the components of the pressure relief valve for excessive wear or damage.
Oil pump PRV
Result: A component in the pressure relief valve is not within specification.
Repair: Repair or replace the pressure relief valve, as necessary. Refer to Disassembly and Assembly, "Engine Oil Relief Valve - Remove and Install".
Result: The pressure relief valve is OK.
Proceed to Test Step 11.
11. Engine Oil Pump
A. Inspect the components of the engine oil pump for excessive wear.
Oil pump
Result: A component in the oil pump is not within specification.
Repair: Repair the oil pump or replace the oil pump, if necessary. Refer to Disassembly and Assembly, "Engine Oil Pump - Remove" and Disassembly and Assembly, "Engine Oil Pump - Install".
Result: The oil pump is OK.
Proceed to Test Step 12.
12. Bearing Clearance
A. Inspect the engine components for excessive bearing clearance or damaged bearings. Inspect the following components for excessive bearing clearance:
Crankshaft main bearings
Connecting rod bearings
Camshaft front bearing
Idler gear bearing
Bearing clearance
Result: An engine bearing is not within specification.
Repair: Install a new bearing. Refer to Disassembly and Assembly.
Result: All engine bearings are within specification.
Contact the Dealer Solutions Network (DSN).