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Home/Suzuki/XL7/Suzuki XL7 I (2007-2009)/Repair manual/Cooling System (Mechanical)/Engine Cooling System: Diagnosis
Contents Wiring diagrams Section: Cooling System (Mechanical) All sections

Engine Cooling System: Diagnosis Suzuki XL7 I

Cooling System (Mechanical) 2 illustrations ~2394 words

Diagnostic Starting Point - Engine Cooling

Begin the system diagnosis with DIAGNOSTIC SYSTEM CHECK - VEHICLE DIAGNOSTIC INFORMATION . The Diagnostic System Check - Vehicle will provide the following information

  1. The identification of the control modules which command the system
  2. The ability of the control modules to communicate through the serial data circuit
  3. The identification of any stored DTCs and the codes status

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls (3.6L) - Engine Cooling

Scan Tool Output ControlAdditional Menu Selection(s)Description
Fan Relay 1Special Functions/Output Control/Cooling FanActivates the cooling fan relay 1. The normal commanded state of the fan relay is NONE. The relay command status can also be monitored on the scan tool data parameter FC Relay 1 Command. The PCM allows cooling fan relay control when the following conditions are met: The ignition is ON or the engine is running A/C compressor operation is not requested. The engine coolant temperature is less than 106°C (224°F).
Fan Relays 2 and 3Special Functions/Output Control/Cooling FanActivates the cooling fan relay 2 and relay 3. The normal commanded state of the fan relays is NONE. The relay command status can also be monitored on the scan tool data parameter FC Relay 2 and 3 Command. The PCM allows cooling fan relay control when the following conditions are met: The ignition is ON or the engine is running A/C compressor operation is not requested. The engine coolant temperature is less than 106°C (224°F).
Fan Relays 1, 2 and 3Special Functions/Output Control/Cooling FanActivates the cooling fan relay 1, relay 2 and relay 3. The normal commanded state of the fan relays is NONE. The relay command status can also be monitored on the scan tool data parameters FC Relay 1 Command and FC Relay 2 and 3 Command. The PCM allows cooling fan relay control when the following conditions are met: The ignition is ON or the engine is running A/C compressor operation is not requested. The engine coolant temperature is less than 106°C (224°F).

SCAN TOOL OUTPUT CONTROLS (3.6L) - ENGINE COOLING

Scan Tool Data List (3.6L) - Engine Cooling

The Engine Scan Tool Data List contains all cooling system related parameters that are available on the scan tool. The list is arranged in alphabetical order. A parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

The column labeled Data List indicates where a parameter is located on the scan tool. Review the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed

All The Parameter is in all data lists indicated below.

Eng Engine Data

Ign Ignition Data

EVAP EVAP Data

FT Fuel Trim Data

HO2S HO2S Data

MF Misfire Data

TAC TAC Data

CMP CMP Actuator Data

CH Cooling/HVAC Data

CT Cruise/Traction Data

ET Electrical/Theft Data

Ind Induction Data

IPC IPC Data

IM I/M Data

Trans Transmission Data

FF Freeze Frame Data

FR Failure Records Data

Scan Tool ParameterData ListParameter Range/UnitsTypical Data Values
Operating Conditions: Engine Idling/Radiator Hose Hot/Park or Neutral/Closed Loop/Accessories Off
Calculated ECT - Thermostat DiagnosisCH39 to +140°C (-38 to +284°F)89°C (192°F)
ECT SensorALL39 to +140°C (-38 to +284°F)Varies
FC Relay 1 Circuit StatusCHFault/Indeterminate/OKIndeterminate
FC Relay 1 CommandCHON/OFFVaries
FC Relay 2 and 3 Circuit StatusCHFault/Indeterminate/OKIndeterminate
FC Relay 2 and 3 CommandCHON/OFFVaries

SCAN TOOL DATA LIST (3.6L) - ENGINE COOLING

Scan Tool Data Definitions (3.6L) - Engine Cooling

The Scan Tool Data Definitions list contains a brief description of all of the cooling system related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists. In some cases the parameter may appear more than once, or in more than one data list in order to group certain related parameters together.

Calculated ECT - Thermostat Diagnosis This parameter displays the modeled temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined amount of time, a DTC will set.

ECT Sensor This parameter displays the temperature of the engine coolant based on input to the control module from the engine coolant temperature (ECT) sensor.

FC Relay 1 Circuit Status This parameter displays the state of the fan relay control circuit. The parameter displays Indeterminate when no circuit fault is detected when the fans are OFF. The parameter displays OK when no circuit fault is detected when the fans are ON.

FC Relay 1 Command This parameter displays the control module commanded state of the fan relay control circuit.

FC Relay 2 and 3 Circuit Status This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate when no circuit fault is detected when the fans are OFF. The parameter displays OK when no circuit fault is detected when the fans are ON.

FC Relay 2 and 3 Command This parameter displays the control module commanded state of the fan relay control circuit.

DTC Table

DTCDescription
P0480Cooling Fan Relay 1 Control Circuit
P0481Cooling Fan Relay 2 Control Circuit
P0691Cooling Fan Relay 1 Control Circuit Low Voltage
P0692Cooling Fan Relay 1 Control Circuit High Voltage
P0693Cooling Fan Relay 2 Control Circuit Low Voltage
P0694Cooling Fan Relay 2 Control Circuit High Voltage

DIAGNOSTIC TROUBLE CODES (DTC) LIST

Diagnostic Instructions

  1. Perform the «DIAGNOSTIC SYSTEM CHECK - VEHICLE DIAGNOSTIC INFORMATION»(ref-268408-S06696600922007102300000) prior to using this diagnostic procedure.
  2. Review «STRATEGY BASED DIAGNOSIS»(ref-268408-S33308238502007102300000) for an overview of the diagnostic approach.
  3. «DIAGNOSTIC PROCEDURE INSTRUCTIONS - VEHICLE DIAGNOSTIC INFORMATION»(ref-268408-S33241872482007102300000) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0480 Cooling Fan Relay 1 Control Circuit

DTC P0481 Cooling Fan Relay 2 Control Circuit

DTC P0691 Cooling Fan Relay 1 Control Circuit Low Voltage

DTC P0692 Cooling Fan Relay 1 Control Circuit High Voltage

DTC P0693 Cooling Fan Relay 2 Control Circuit Low Voltage

DTC P0694 Cooling Fan Relay 2 Control Circuit High Voltage

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Relay Coil Ignition CircuitP0691, P0693P0480, P0481
Relay Switch Ignition Circuit(1)(1)
Fan Relay 1 Control CircuitP0691P0480P0692
Fan Relay 2 and Fan Relay 3 Control CircuitP0693P0481P0694
Relay Controlled Output Circuit(1)(1)(2)
(1) Fans inoperative without a DTC. (2) Fans always ON without a DTC.
(1)Fans inoperative without a DTC.
(2)Fans always ON without a DTC.

DIAGNOSTIC FAULT INFORMATION

Conditions for Running the DTC

  1. The ignition voltage is between 8-18 volts.
  2. The engine speed is more than 40 RPM.
  3. The ECM driver transitions from ON to OFF or from OFF to ON.

Conditions for Clearing the MIL/DTC

DTCs P0480, P0481, P0691, P0692, P0693, and P0694 are Type B DTCs.

Diagnostic Aids

  1. The ECM has the capability of providing command to the fan relays even when a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.
  2. The following tables illustrate the FAN 1 relay, FAN 2 relay and the FAN 3 relay terminal locations in the underhood fuse block: COOLING FAN 1 RELAY TERMINAL IDENTIFICATION Cooling FAN 1 Relay Terminal Identification B+ - Switch Control B+ - Coil Cooling Fan Supply Voltage Front of Vehicle COOLING FAN 2 RELAY TERMINAL IDENTIFICATION Cooling FAN 2 Relay Terminal Identification Voltage from Left Cooling Fan Control - Voltage to Right Cooling Fan B+ - Coil Ground Front of Vehicle COOLING FAN 3 RELAY TERMINAL IDENTIFICATION Cooling FAN 3 Relay Terminal Identification Control Cooling Fan Supply Voltage B+ - Switch B+ - Coil Front of Vehicle

Component Testing

  1. Measure for 70-110 ohms of resistance between terminals 85 and 86 of the relay. If the resistance is not within the specified range, replace the relay.
  2. Measure for infinite resistance between the following terminals of the relay: 30 and 86 30 and 87 30 and 85 85 and 87 If continuity is detected, replace the relay.
  3. Connect a 20-amp fused jumper wire from the positive terminal of the battery to relay terminal 85. Connect a jumper wire from the negative terminal of the battery to relay terminal 86. Measure for less than 2 ohms between terminals 30 and 87 of the relay. If the resistance measures more than the specified value, replace the relay.

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to «CHECKING AFTERMARKET ACCESSORIES»(ref-268410-S24071910952007102300000) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. «COOLING FAN ALWAYS ON»(ref-268430-S02819803502007102300000)
  2. «COOLING FAN INOPERATIVE»(ref-268430-S07086277232007102300000)
  3. «ENGINE OVERHEATING»(ref-268430-S11727852142007102300000)
  4. «LOSS OF COOLANT»(ref-268430-S42633239872007102300000)
  5. «THERMOSTAT DIAGNOSIS»(ref-268430-S04246359332007102300000)
  6. «ENGINE FAILS TO REACH NORMAL OPERATING TEMPERATURE»(ref-268430-S13425372282007102300000)
  1. Perform the «DIAGNOSTIC SYSTEM CHECK - VEHICLE DIAGNOSTIC INFORMATION»(ref-268408-S06696600922007102300000) prior to using this diagnostic procedure.
  2. Review «STRATEGY BASED DIAGNOSIS»(ref-268408-S33308238502007102300000) for an overview of the diagnostic approach.
  3. «DIAGNOSTIC PROCEDURE INSTRUCTIONS - VEHICLE DIAGNOSTIC INFORMATION»(ref-268408-S33241872482007102300000) provides an overview of each diagnostic category.
  1. The ECM has the capability of providing command to the fan relays even when a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.
  2. The following tables illustrate the FAN 1 relay, FAN 2 relay and the FAN 3 relay terminal locations in the underhood fuse block: COOLING FAN 1 RELAY TERMINAL IDENTIFICATION Cooling FAN 1 Relay Terminal Identification B+ - Switch Control B+ - Coil Cooling Fan Supply Voltage Front of Vehicle COOLING FAN 2 RELAY TERMINAL IDENTIFICATION Cooling FAN 2 Relay Terminal Identification Voltage from Left Cooling Fan Control - Voltage to Right Cooling Fan B+ - Coil Ground Front of Vehicle COOLING FAN 3 RELAY TERMINAL IDENTIFICATION Cooling FAN 3 Relay Terminal Identification Control Cooling Fan Supply Voltage B+ - Switch B+ - Coil Front of Vehicle

Circuit/System Testing

  1. Ignition OFF, disconnect each cooling fan relay one at a time.
  2. Ignition ON, observe that the cooling fans are OFF. If the fans are ON, test for a short to voltage in the relay switch supply circuits. If the fans are OFF, test or replace the appropriate cooling fan relay.
  1. Ignition OFF, disconnect the cooling fan relay.
  2. Test for 70-110 ohms of resistance between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
  4. Test for less than 2 ohms of resistance between terminals 30 and 87A. If greater than the specified value, replace the relay.
  5. Install a 20A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms of resistance between terminals 30 and 87. If greater than the specified value, replace the relay.
  1. Perform the «DIAGNOSTIC SYSTEM CHECK - VEHICLE DIAGNOSTIC INFORMATION»(ref-268408-S06696600922007102300000) prior to using this diagnostic procedure.
  2. Review «STRATEGY BASED DIAGNOSIS»(ref-268408-S33308238502007102300000) for an overview of the diagnostic approach.
  3. «DIAGNOSTIC PROCEDURE INSTRUCTIONS - VEHICLE DIAGNOSTIC INFORMATION»(ref-268408-S33241872482007102300000) provides an overview of each diagnostic category.
  1. The ECM has the capability of providing command to the fan relays even when a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.
  2. The following tables illustrate the FAN 1 relay, FAN 2 relay and the FAN 3 relay terminal locations in the underhood fuse block: COOLING FAN 1 RELAY TERMINAL IDENTIFICATION Cooling FAN 1 Relay Terminal Identification B+ - Switch Control B+ - Coil Cooling Fan Supply Voltage Front of Vehicle COOLING FAN 2 RELAY TERMINAL IDENTIFICATION Cooling FAN 2 Relay Terminal Identification Voltage from Left Cooling Fan Control - Voltage to Right Cooling Fan B+ - Coil Ground Front of Vehicle COOLING FAN 3 RELAY TERMINAL IDENTIFICATION Cooling FAN 3 Relay Terminal Identification Control Cooling Fan Supply Voltage B+ - Switch B+ - Coil Front of Vehicle
  1. Ignition OFF, disconnect the cooling fan relays.
  2. Ignition ON, one at a time, verify that a test lamp illuminates between the relay switch B+ circuit terminal 30 and ground. If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay switch B+ circuit fuse is open, test all components connected to the relay switch B+ circuit and replace as necessary.
  3. Connect a 30A fused jumper between the relay switch B+ circuit terminal 30 and the relay supply circuit terminal 87 at the FAN 2 relay connector. This will in complete the left side or main fan ground circuit. Leave this jumper in place for the remainder of this procedure.
  4. One at a time, connect a 30A fused jumper between the relay switch B+ circuit terminal 30 and the relay switch supply circuit terminal 87 of the applicable fan relay. Verify the appropriate fan turns ON. If the appropriate fan does not turn ON, test the relay switch supply circuit for a short to ground or open/high resistance. If the circuit tests normal, test the fan ground circuit for open/high resistance. If the circuit tests normal, replace the fan.
  5. If all circuits test normal, test or replace the appropriate cooling fan relays.
  1. Ignition OFF, disconnect the cooling fan relay.
  2. Test for 70-110 ohms of resistance between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
  4. Test for less than 2 ohms of resistance between terminals 30 and 87A. If greater than the specified value, replace the relay.
  5. Install a 20A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms of resistance between terminals 30 and 87. If greater than the specified value, replace the relay.

Thermostat Diagnosis

Special Tool

J 24731 188 Tempilstick

J 24731 206 Tempilstick

The coolant thermostat can be tested using a temperature (tempil) stick. The temperature stick is a pencil-like device which has a wax material containing certain chemicals that melt at a given temperature. Temperature sticks can be used to determine a thermostat's operating range by rubbing 87°C (188°F) and 97°C (206°F) sticks on the outlet coolant pipe.

  1. Use a tempilstick in order to find the opening and the closing temperatures of the thermostat. J 24731 188 tempilstick melts at 87°C (188°F). The thermostat should begin to open at 90°C (194°F). J 24731 206 tempilstick melts at 97°C (206°F). The thermostat should be fully open at 107°C (225°F).
  2. Replace the thermostat if it does not operate properly between this temperature range.

Pressure Cap Testing

Special Tool

  1. J 24460-01 Cooling System Pressure Tester
  2. J 42401 Radiator Cap/Surge Tank Test Adapter
WARNINGTo avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

Scheme 1

Scheme 1
Scheme 1
  1. Remove the pressure cap.
  2. Wash the pressure cap sealing surface with water.
  3. Use the J 24460-01 (1) with J 42401 (2) in order to test the pressure cap.
  4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. Maintain the rated pressure for at least 10 seconds. Note the rate of pressure loss.
  5. Replace the pressure cap under the following conditions: The pressure cap does not release pressure which exceeds the rated pressure of the cap. The pressure cap does not hold the rated pressure.

Cooling System Leak Testing

Special Tool

J 24460-01 Cooling System Pressure Tester

J 42401 Radiator Cap/Surge Tank Test Adapter

WARNINGUnder pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire. In order to help avoid being burned, do not remove the radiator cap while the engine and the radiator are hot. Scalding fluid and steam can be blown out under pressure if the cap is removed too soon.

Scheme 2

Scheme 2
Scheme 2
  1. Remove the pressure cap.
  2. Test the operation of the pressure cap. Refer to «PRESSURE CAP TESTING»(ref-268430-S09704046012007102300000) .
  3. Wash the pressure cap mating surface with water.
  4. Use the J 24460-01 with J 42401 in order to apply pressure to the cooling system. Wet the O-rings on the Surge Tank Pressure Test Adapter J 42401-2 (insert) with water or clean coolant and insert into tank. Wet the rubber gasket of the cap adapter J 42401-3 (cap) and install on surge tank. NOTE: Do not exceed the pressure cap rating.
  5. The cooling system should hold the rated pressure for at least 2 minutes. Observe the gage for any pressure loss.
  6. Repair any leaks as required.

Water Pump Cleaning and Inspection

Reference: WATER PUMP REMOVAL .

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