OVERHEATING CAUSE ANALYSIS
Troubleshooting Chart
| Symptom | Check items | |||
| Cooling system parts malfunction | Poor heat transfer | Water pump malfunction | Worn or loose drive belt | — |
| Thermostat stuck closed | Engine coolant circulation | |||
| Damaged fins | Dust contamination or rock clogging | |||
| Mechanical damage | ||||
| Clogged radiator cooling tube | Excess foreign material (rust, dirt, sand, etc.) | |||
| Reduced air flow | Cooling fan does not operate | Fan shroud and motor as- High resistance to fan rota- sembly | — | |
| High resistance to fan rotation | ||||
| Damaged fan blades | ||||
| Damaged radiator shroud | — | Radiator shroud | — | |
| Improper engine coolant mixture ratio | — | Engine coolant viscosity | — | |
| Poor engine coolant quality | — | Periodic maintenance | — | |
| Insufficient engine coolant | Engine coolant leaks | Cooling hose | Loose clamp | |
| Cracked hose | ||||
| Water pump | Poor sealing | |||
| Radiator cap | Loose | |||
| Poor sealing | ||||
| Radiator | O-ring for damage, deterioration or improper fitting | |||
| Cracked radiator tank | ||||
| Cracked radiator core | ||||
| Reservoir tank | Cracked reservoir tank | |||
| Overflowing reservoir tank | Exhaust gas leaks into cooling system | Cylinder head deterioration | ||
| Cylinder head gasket deterioration | ||||
| Except cooling system parts malfunction |
— |
Overload on engine | Abusive driving | High engine rpm under no load |
| Driving in low gear for extended time | ||||
| Driving at extremely high speed | ||||
| Powertrain system malfunction |
— |
|||
| Installed improper size wheels and tires | ||||
| Dragging brakes | ||||
| Improper ignition timing | ||||
| Blocked or restricted air flow | Blocked radiator grille | Installed car brassiere | — | |
| Blocked bumper | ||||
| Blocked radiator | ||||
| Blocked condenser | Mud contamination or paper clogging | |||
| Installed large fog lamp | ||||
System description
Periodic maintenanceDrive belt
Automatic tensioner
Generator
Water pump
Air conditioner compressor
Crankshaft pully
WARNINGBe sure the ignition switch is in the OFF
or
LOCK position before servicing drive belt.
The engine could rotate unexpectedly.
Visually inspect the belt for signs of ...
Basic inspection
Diagnosis and repair work flow
Work flow
Overall sequence
Detailed flow
1.Get information for symptom
Get the detailed information from the customer about the symptom (the
condition and the environment when
the incident/malfunction occurred) using the “diagnostic work sheet”. ( ...
C1121, C1123, C1125, C1127 ABS OUT Valve system
DTC Logic
DTC DETECTION LOGIC
DTC DETECTION LOGIC
Display Item
Malfunction detected condition
Possible causes
C1121
FR LH OUT ABS SOL
When a malfunction is detected in front LH ABS OUT
valve.
Harness or connector
ABS actuator and electric unit
...