Engine Cooling Symptom Diagnosis
| Condition | Possible Cause | Action |
|---|---|---|
| Engine overheats (Radiator fan operates) | Loose or broken accessory drive belt | Check accessory drive belt See ACCESSORY DRIVE BELT TENSION INSPECTION . |
| Not enough coolant | Check coolant level and add as necessary . | |
| Faulty thermostat | Check thermostat See Thermostat Inspection . | |
| Faulty water pump | Check water pump See Water Pump Inspection . | |
| Dirty or bent radiator fins | Clean or remedy . | |
| Coolant leakage on cooling system | Check cooling system for leakage See Engine Cooling System Inspection . | |
| Clogged radiator | Replace radiator . See Radiator Removal and Installation | |
| Faulty radiator cap | Check radiator cap . | |
| Dragging brakes | Check brake See BRAKES SYMPTOM DIAGNOSIS . | |
| Slipping clutch | Check clutch See CLUTCH SYSTEM SYMPTOM DIAGNOSIS . | |
| Poor charged battery | Check battery . | |
| Poor electricity generated by generator | Check generator See GENERATOR TEST . | |
| ECT sensor faulty | Check ECT sensor . See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION | |
| Radiator cooling fan motor faulty | Check radiator cooling fan motor . See Radiator Cooling Fan Assembly On-Vehicle Inspection | |
| ECM faulty | Check ECM and its circuit . See INSPECTION OF ECM AND ITS CIRCUITS | |
| Wiring or grounding faulty | Repair wiring . | |
| Equipped with too many additional electrical part(s) | Dismount them . | |
| Engine overheats (Radiator fan does not operate) | Fuse blown | Check fuse . |
| Radiator cooling fan relay faulty | Check radiator cooling fan relay . See Radiator Cooling Fan Relay Inspection | |
| ECT sensor faulty | Check ECT sensor . See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION | |
| Radiator cooling fan motor faulty | Check radiator cooling fan motor . See Radiator Cooling Fan Assembly On-Vehicle Inspection | |
| Wiring or grounding faulty | Repair as necessary. | |
| ECM faulty | Check ECM and its circuit . See INSPECTION OF ECM AND ITS CIRCUITS |
ENGINE COOLING DIAGNOSTIC INFORMATION AND PROCEDURES
Troubleshooting
| WARNING | The radiator cooling fan can come on whenever the ignition switch is in the "ON" position. This electric fan starts automatically anytime the ECT sensor senses a coolant temperature higher than a predetermined level even when the engine is not running. When the ignition switch is in the ON position, be sure to keep hands, tools, clothing, and other items away from the radiator cooling fan and drive belt. |
Note. For details about engine cooling fan operation, refer to " COOLING FAN OPERATION DESCRIPTION ": Before beginning troubleshooting, be sure to read PRECAUTIONS FOR ECM CIRCUIT INSPECTION . When measuring circuit voltage, resistance and/or pulse signal of ECM.
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | DTC Check Turn OFF ignition switch and connect SUZUKI scan tool to DLC. Turn ignition switch to ON position and check DTC. Is there DTC(s)? | Go to applicable DTC troubleshooting and recheck. | Go to Step 2. |
| 2 | Radiator cooling fan low mode control check Check radiator cooling fan control for low mode. See Radiator Cooling Fan Assembly On-Vehicle Inspection Is it in good condition? | Go to Step 3. | Go to Step 4. |
| 3 | Radiator cooling fan high mode control check Check radiator cooling fan control for high mode. See Radiator Cooling Fan Assembly On-Vehicle Inspection Is it in good condition? | Radiator cooling fan control system is in good condition. | Go to Step 8. |
| 4 | Radiator cooling fan relay No. 1 power supply circuit (switch side) check Turn OFF ignition switch and remove radiator cooling fan relay No. 1 from relay box No. 1. Check for proper connection to radiator cooling fan relay No. 1 at each terminal. If OK, measure voltage between radiator cooling fan relay No. 1 power supply circuit (A1) and vehicle body ground. Is it 10 - 14 V? | Go to Step 5. | Repair or replace radiator cooling fan relay No. 1 power supply circuit (switch side). |
| 5 | Radiator cooling fan relay No. 1 check Check radiator cooling fan relay No. 1. See Radiator Cooling Fan Relay Inspection Is it in good condition? | Go to Step 6. | Replace radiator cooling fan relay No. 1. |
| 6 | Radiator cooling fan motor drive circuit (low speed) check Turn OFF ignition switch and disconnect radiator cooling fan motor connector. Check for proper connection to radiator cooling fan motor at each terminal. If OK, check that radiator cooling fan motor drive circuit (low speed) (B1) is in the following conditions. Wiring harness resistance of radiator cooling fan motor drive circuit (low speed) is less than 3 ohms or less. Insulation resistance between radiator cooling fan drive circuit (low speed) and vehicle body ground is infinity. Circuit voltage of radiator cooling fan motor drive circuit (low speed) is 0 - 1 V with ignition switch in ON position. Are they in good condition? | Go to Step 7. | Repair or replace radiator cooling fan motor drive circuit (low speed). |
| 7 | Radiator cooling fan motor ground circuit check Measure resistance between radiator cooling fan motor ground circuit (C1) and vehicle body ground. Is resistance 3 ohms or less? | Go to Step 14. | Repair or replace radiator cooling fan motor ground circuit. |
| 8 | Radiator cooling fan relay No. 2 power supply circuit (switch side) check Turn OFF ignition switch and remove radiator cooling fan relay No. 2 from relay box No. 1. Check for proper connection to radiator cooling fan relay No. 2 at each terminal. If OK, measure voltage between radiator cooling fan relay No. 2 power supply circuit (A2) and vehicle body ground. Is it 10 - 14 V? | Go to Step 9. | Repair or replace radiator cooling fan relay No. 2 power supply circuit (switch side). |
| 9 | Radiator cooling fan relay No. 2 check Check radiator cooling fan relay No. 2. See Radiator Cooling Fan Relay Inspection Is it in good condition? | Go to Step 10. | Replace radiator cooling fan relay No. 2. |
| 10 | Radiator cooling fan motor drive circuit (high speed) check Turn OFF ignition switch and disconnect radiator cooling fan motor connector. Check for proper connection to radiator cooling motor at each terminal. If OK, check that radiator cooling motor drive circuit (high speed) (B2) is in the following conditions. Wiring harness resistance of radiator cooling fan motor drive circuit (high speed) is 3 ohms or less. Insulation resistance between radiator cooling fan motor drive circuit (high speed) and vehicle body ground is infinity. Circuit voltage of radiator cooling fan motor drive circuit (high speed) is 0 - 1 V with ignition switch in ON position. Is it in good condition? | Go to Step 11. | Repair or replace cooling motor drive circuit (high speed). |
| 11 | Radiator cooling fan relay No. 3 power supply circuit (switch side) check Check that radiator cooling fan relay No. 3 power supply circuit (switch side) (A3) is in the following conditions. Wiring harness resistance of radiator cooling fan relay No. 3 power supply circuit (switch side) is 3 ohms or less. Insulation resistance between radiator cooling fan relay No. 3 power supply circuit (switch side) and vehicle body ground is infinity. Circuit voltage of radiator cooling fan relay No. 3 power supply circuit (switch side) is 0 - 1 V with ignition switch in ON position. Is it in good condition? | Go to Step 12. | Repair or replace radiator cooling fan relay No. 3 power supply circuit (switch side). |
| 12 | Radiator cooling fan relay No. 3 check Check radiator cooling fan relay No. 3. See Radiator Cooling Fan Relay Inspection Is it in good condition? | Go to Step 13. | Replace radiator cooling fan relay No. 3. |
| 13 | Radiator cooling fan relay No. 3 ground circuit check Measure resistance between radiator cooling fan motor ground circuit (C2) and vehicle body ground. Is resistance 3 ohms or less? | Go to Step 14. | Repair or replace cooling fan relay No. 3 ground circuit. |
| 14 | Radiator cooling fan motor check Check radiator cooling fan motor. Is it in good condition? | Substitute a known-good ECM and recheck. | Replace radiator cooling fan motor. |
DIAGNOSTIC INFORMATION AND PROCEDURES REFERENCE CHART
Scheme 1
Thermostat Inspection
Reference: THERMOSTAT REMOVAL AND INSTALLATION
Scheme 2
- Make sure that air bleed valve (1) of thermostat is clean.
- Check to make sure that valve seat (2) is free from foreign matters which would prevent valve from seating tight.
- Check thermostat gasket (3) for breakage, deterioration or any other damage.
- Check thermostatic movement of wax pellet as follows: Immerse thermostat (1) in water, and heat water gradually. Check that valve starts to open at specific temperature. Temperature at which valve begins to open 80 - 84 °C (176 - 183 °F) Temperature at which valve become fully open 95 - 97 °C (203 - 206 °F) Valve lift More than 8 mm (0.31 in.) at 95 °C (203 °F)
If valve starts to open at a temperature substantially below or above specific temperature, thermostat unit should be replaced with a new one. Such a unit, if reused, will bring about overcooling or overheating tendency.
Scheme 3
Scheme 4
- Connect scan tool to DLC (1) with ignition switch OFF. Special Tool (A): SUZUKI scan tool (SUZUKI-SDT)
- Turn ignition switch to ON position and clear DTC. See «DTC CLEARANCE»(ref-514565-S22591084692012112100000)
- Select the "Radiator Fan" function in "Active Test".
- Check radiator cooling fan operation at low and high modes. If any abnormality is found, check cooling fan control system referring to «RADIATOR COOLING FAN CONTROL SYSTEM CHECK»(ref-514579-S01973220422012112100000) . RADIATOR COOLING FAN OPERATION REFERENCE CHART Radiator cooling fan motor OFF OFF Low mode Low speed High mode High speed
Scheme 5
- Disconnect radiator cooling fan motor connector (1).
- Using service wire, connect radiator cooling fan motor connector and battery as shown in figure.
- Check that radiator cooling fan motors rotate smoothly and properly. If any abnormality is found, replace corresponding radiator cooling fan motor. Reference: Fan motor specified current at 12 V LOW: 4.8 - 7.8 A HIGH: 7.4 - 10.9 A
Scheme 6
- Disconnect negative (-) cable at battery.
- Remove radiator cooling fan relay No. 1 (1), No. 2 (2) and/or No. 3 (3) from relay box.
- Check radiator cooling fan relays as follows. Check that there is no continuity between terminals "C" and "D". If there is continuity, replace relay. Connect battery positive (+) terminal to terminal "B" of relay. Connect battery negative (-) terminal to terminal "A" of relay. Check continuity between terminals "C" and "D". If there is no continuity, replace relay.
Inspection
Check radiator for leakage or damage. Straighten bent fins, if any.
Water Pump Inspection
Reference: WATER PUMP REMOVAL AND INSTALLATION
| CAUTION | The water pump will lose its original performance if it has been disassembled and reassembled. Do not try to disassemble and repair the water pump. If any faulty condition is found, replace the water pump assembly with a new one. |
Rotate water pump by hand to check for smooth operation. If pump does not rotate smoothly or makes abnormal noise, replace it.
