| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Electrical system circuit open (battery — starter switch) | Repair or replace. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Battery — starter — starter switch circuit open | Repair or replace. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Starter or starter relay defective | Consult Mitsubishi dealer. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Battery weak | Adjust alternator drive belt. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Electrolyte specific gravity low | Recharge. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Battery will not recover even if recharged | Change. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Engine oil viscosity too high | Refill with oil of proper viscosity. |
| Starter will not crank engine or cranks slowly, resulting in a failure of engine to start | Mechanical failure: interference between pistons and valves; foreign matter in cylinder | Consult Mitsubishi dealer. |
| Starter will crank engine, but engine will not start | Fuel tank empty | Refuel. |
| Starter will crank engine, but engine will not start | Fuel leaks from pipe connection | Consult Mitsubishi dealer. |
| Starter will crank engine, but engine will not start | Air in fuel system | Prime. |
| Starter will crank engine, but engine will not start | Wrong type of fuel | Refill with correct type of fuel. |
| Starter will crank engine, but engine will not start | Dirt or water in fuel | Remove dirt or drain. |
| Starter will crank engine, but engine will not start | Fuel filter clogged | Change. |
| Starter will crank engine, but engine will not start | Fuel pipe clogged or leaky | Clean or repair. |
| Starter will crank engine, but engine will not start | Injection pump defective | Consult Mitsubishi dealer. |
| Starter will crank engine, but engine will not start | Air cleaner clogged | Clean element. |
| Starter will crank engine, but engine will not start | Compression pressure low: cylinders, piston and piston rings worn; valve springs broken; valve seats and injection nozzle packings defective | Consult Mitsubishi dealer. |
| Starter will not crank engine (air-motor starting) | Air pressure low | Run air compressor to increase air pressure. |
| Starter will not crank engine (air-motor starting) | Starter switch defective | Repair or replace. |
| Starter will not crank engine (air-motor starting) | Magnetic valve defective | Repair or replace. |
| Starter will run, but starter pinion will not engage with flywheel ring gear | Ring gear or pinion defective | Consult Mitsubishi dealer. |
| Starter pinion engages with ring gear, but starter will not crank engine | Air pressure low | Run air compressor to increase air pressure. |
| Engine will not be cranked (direct-air starting) | Air pressure low | Run air compressor to increase air pressure. |
| Engine will not be cranked (direct-air starting) | Air filter clogged | Clean or change. |
| Engine will not be cranked (direct-air starting) | Starter valve stuck | Consult Mitsubishi dealer. |
| Engine lacks power | Incorrect grade of oil | Use recommended type and SAE number of oil. |
| Engine lacks power | Wrong type of fuel | Change. |
| Engine lacks power | Insufficient air (air cleaner clogged) | Clean or change element. |
| Engine lacks power | Engine overcooled | Use radiator cover, replace parts. |
| Engine lacks power | Fuel feed pump gauze filter clogged | Clean gauze filter. |
| Engine lacks power | Engine overheating | Flush cooling system or replace parts. |
| Engine lacks power | Valve clearance incorrect | Readjust. |
| Engine lacks power | Injection pump defective | Readjust or replace. |
| Engine lacks power | Injection nozzles defective | Readjust or replace. |
| Engine lacks power | Injection timing incorrect | Readjust. |
| Engine lacks power | Compression pressure low (cylinders and pistons worn) | Disassemble and replace parts. |
| White or blue exhaust smoke | Too much oil in crankcase | Fill only to correct level on gauge. |
| White or blue exhaust smoke | Oil viscosity too low | Refill with correct viscosity of oil. |
| White or blue exhaust smoke | Engine overcooled | Use radiator cover, or clean, test and replace thermostat. |
| White or blue exhaust smoke | Thermostat defective (no water temperature rise) | Replace. |
| White or blue exhaust smoke | Injection timing incorrect | Readjust. |
| White or blue exhaust smoke | Compression pressure low | Disassemble and replace parts. |
| White or blue exhaust smoke | Wrong type of fuel (low cetane number) | Change. |
| Black or gray exhaust smoke | Wrong type of fuel | Refill with correct type of fuel. |
| Black or gray exhaust smoke | Valve clearance incorrect | Readjust. |
| Black or gray exhaust smoke | Injection pump defective | Readjust or replace. |
| Black or gray exhaust smoke | Compression pressure low | Disassemble and replace parts. |
| Black or gray exhaust smoke | Insufficient air (air cleaner clogged) | Clean or change element. |
| High fuel consumption | Injection pump defective | Readjust or replace. |
| High fuel consumption | Injection nozzles defective | Readjust or replace. |
| High fuel consumption | Injection timing incorrect | Readjust. |
| High fuel consumption | Wrong type of fuel | Refill with correct type of fuel. |
| High fuel consumption | Compression pressure low | Disassemble and replace parts. |
| High fuel consumption | Insufficient air | Clean or change air cleaner element. Check turbocharger. |
| High oil consumption | Too high oil level in crankcase | Maintain oil level in correct range on gauge. |
| High oil consumption | Incorrect grade of oil | Use recommended type and SAE number of oil. |
| High oil consumption | Oil leaks | Retighten or replace. |
| High oil consumption | Cylinders and piston rings worn | Disassemble and replace parts. |
| Engine overheating | Radiator or heat exchanger dirty | Wash. |
| Engine overheating | Friction rubber deteriorated | Replace. |
| Engine overheating | Lack of coolant | Refill. |
| Engine overheating | Water pump defective | Replace. |
| Engine overheating | Thermostat defective | Replace. |
| Low oil pressure | Lack of oil | Refill up to level. |
| Low oil pressure | Oil viscosity too low | Refill with correct viscosity of oil. |
| Low oil pressure | Oil filter clogged | Replace element. |
| Low oil pressure | Oil pump defective | Readjust, replace or clean. |
| Low oil pressure | Oil pressure regulating valve defective | Readjust or replace. |
| Low oil pressure | Oil pressure sensor circuit defective | |