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Engine Cooling System: Diagnosis Pontiac Solstice I

Cooling System (Mechanical) ~1845 words

DIAGNOSTIC CODE INDEX

DTCDescription
DTC P0480 or P0481 (2.4L)Low/High Speed Cooling Fan Relay Control Circuit
DTC P0480, P0691, or P0692 (2.0L)Cooling Fan Speed Output Circuit Related

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Engine Cooling

Begin the system diagnosis with the diagnostic system check. Refer to Diagnostic System Check - Vehicle . 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 circuits
  3. The identification of any stored DTCs and their 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

Scan Tool Output ControlAdditional Menu Selection(s)Description
Cooling Fan 1 RelayEngine Output ControlsThe scan tool displays a Commanded State of None, Off or On. This allows you to communicate with the engine controller and activate or deactivate the cooling fan 1 relay, manually turning the fans On and Off.
Cooling Fan 2 RelayEngine Output ControlsThe scan tool displays a Commanded State of None, Off or On. This allows you to communicate with the engine controller and activate or deactivate the cooling fan 2 relay, manually turning the fans On and Off.

Scan Tool Output Controls

Scan Tool Data List

Scan Tool ParameterData ListUnits DisplayedTypical Data Value
Ignition Switch in RUN/Engine running/Automatic Transmission in PARK/Air Conditioner is OFF
ECTHVAC Data°C/°FVaries
FC Relay 1 CommandHVAC DataON/OFFOFF
FC Relay 2 CommandHVAC DataON/OFFOFF
FC Relay 1 Circuit StatusHVAC DataOK/Open/Short/Invalid StateOK
FC Relay 2 Circuit StatusHVAC DataOK/Open/Short/Invalid StateOK

Powertrain Control Module (2.4L)

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Low Speed Cooling Fan Relay Control CircuitP0480P0480P0480
Low Speed Cooling Fan Relay Coil Voltage Supply CircuitP0480P0480P0480
High Speed Cooling Fan Relay Control CircuitP0481P0481P0481
High Speed Cooling Fan Relay Coil Voltage Supply CircuitP0481P0481P0481

DTC P0480 or P0481 (2.4L)

Conditions for Running the DTC

  1. The ignition is ON.
  2. The system voltage is between 9-18 volts.

Conditions for Setting the DTC

  1. An improper voltage level has been detected on the cooling fan relay control circuit.
  2. The condition must be present for a minimum of 30 seconds.

Action Taken When the DTC Sets

  1. DTC P0480 is a Type B DTC.
  2. DTC P0481 is a Type B DTC.

Conditions for Clearing the DTC

  1. DTC P0480 is a Type B DTC.
  2. DTC P0481 is a Type B DTC.

Circuit/System Testing

  1. Ignition OFF, disconnect the affected relay.
  2. Ignition ON, connect a test lamp between the positive terminal at the battery and the relay control circuit terminal.
  3. Command the relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Connect a 30A fused jumper between the positive voltage terminal at the battery and the fan voltage supply circuit terminal and verify fan activation. If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fan.
  5. Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal and verify fan activation. If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If all circuits test normal, replace the relay.
  6. Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit terminal and ground. If the test lamp does not illuminate, test the relay coil voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, replace the relay.
  7. If all circuits and the ECM test normal, replace the affected relay.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Speed Control CircuitP0691P0480P0692P0480

DTC P0480, P0691, or P0692 (2.0L)

  1. The engine speed is more than 80 RPM.
  2. The system voltage is between 10-18 volts.
IMPORTANTThe Circuit/System Verification must be performed first or misdiagnosis may result.
  1. Ignition OFF, disconnect the cooling fan speed control module.
  2. Ignition OFF, install a test lamp between the cooling fan speed control circuit terminal 4 and B+. The lamp should be OFF. If the lamp is ON, test the cooling fan speed control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  3. Ignition ON, command the cooling fan speed from 10-90 percent with a scan tool. The brightness of the lamp should change with the commanded states. If the lamp brightness does not change correctly, test the cooling fan speed control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  4. If the ECM and the control circuit test normal, replace the cooling fan assembly.

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to «Checking Aftermarket Accessories»(ref-267924-S19208784672007101700000) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
  3. Inspect the surge tank reservoir for the proper coolant level.

Symptom List

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

  1. «Cooling Fan Always On (2.4)»(ref-267956-S03116179082007101700000) or «Cooling Fan Always On (2.0)»(ref-267956-S04893851302007101700000)
  2. «Cooling Fan Inoperative (2.4)»(ref-267956-S34393440402007101700000) or «Cooling Fan Inoperative (2.0)»(ref-267956-S06054613382007101700000)
  3. «Engine Overheating»(ref-267956-S18001799662007101700000)
  4. «Loss of Coolant»(ref-267956-S33296781512007101700000)
  5. «Thermostat Diagnosis»(ref-267956-S16073401512007101700000)
  6. «Engine Fails To Reach Normal Operating Temperature»(ref-267956-S19738696842007101700000)
  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition 1Lamp ONLamp ON
Coolant Level Switch SignalLamp ONLamp ONLamp OFF

Low Engine Coolant Indicator Always On

IMPORTANTCircuit/System Verification must be performed before performing the Circuit/System Testing.
  1. Turn ON the ignition, with the engine OFF.
  2. Verify that the low coolant indicator turns ON and OFF with each command when the instrument cluster indicators are commanded ON and OFF with a scan tool. If the low coolant level indicator does NOT turn OFF, test for poor connections at the IPC or a faulty IPC.
  3. Ignition ON, disconnect the coolant level switch.
  4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test the circuit for a short to ground.
  5. Ignition ON, use a 3A fused jumper wire to connect harness terminal A to terminal B. If the low coolant level indicator turns OFF, replace the coolant level switch. If the low coolant level indicator does not turn OFF, test the signal circuit of the coolant switch for an open circuit or high resistance. If the signal circuit test normal, inspect for poor connections at the BCM or a faulty BCM.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
IMPORTANTYou must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
  1. Ignition OFF, disconnect the relays.
  2. Ignition ON, observe that the fan is not activated. If the fan is not activated, replace the faulty relay. If the fan is activated, test the fan voltage supply circuits for a short to voltage.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
IMPORTANTYou must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
  1. Ignition OFF, disconnect the relay.
  2. Ignition OFF, connect a 30A fused jumper between the positive terminal at the battery and the fan voltage supply circuit terminal and verify fan activation. If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the fan does not activate and the circuits test normal, replace the fan.
  3. Ignition ON, connect a 30A fused jumper from the relay switch voltage supply circuit terminal to the fan voltage supply circuit terminal and verify fan activation. If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary.
  4. If the fan and all circuits test normal, replace the faulty relay.
  1. Perform the «Diagnostic System Check - Vehicle»(ref-267923-S26873286382007101700000) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(ref-267923-S16575275542007101700000) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(ref-267923-S13300682012007101700000) provides an overview of each diagnostic category.
IMPORTANTThe Circuit/System Verification must be performed first or misdiagnosis may result.
  1. Ignition OFF, disconnect the cooling fan speed control module.
  2. Ignition OFF, measure between ground and the cooling fan speed control module ground circuit terminal 2 at the engine harness connector for less than 1 ohm of resistance. If more than 1 ohm, test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the cooling fan control module voltage supply circuit terminal 1 and ground. The lamp should illuminate. If the lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, replace the cooling fan assembly.
  4. If all circuits test normal, replace the cooling fan assembly.

Thermostat Test Procedure Using Glycol

Inspect the operation of the thermostat by hanging the thermostat on a hook in a 33 percent glycol solution.

In order to inspect if the thermostat valve is opening properly, perform the following test

  1. Completely submerge the thermostat in a glycol solution. The solution should be 11°C (22°F) above the temperature indicated on the thermostat valve.
  2. Thoroughly agitate the solution. Under these conditions, the thermostat valve should open.

In order to inspect if the thermostat valve is closing properly, perform the following test

  1. Completely submerge the thermostat in a glycol solution. The solution should be 6°C (10°F) below the temperature indicated on the thermostat valve.
  2. Thoroughly agitate the solution. Under these conditions, the thermostat valve should close completely.

Pressure Cap Testing

Tools Required

  1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(ref-267956-S32146669372007101700000) .
  2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(ref-267956-S32146669372007101700000) .
  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. See «Special Tools»(ref-267956-S32146669372007101700000) .
  4. Test the pressure cap for the following conditions: Pressure release when the J 24460-01 exceeds the pressure rating of the pressure cap. See «Special Tools»(ref-267956-S32146669372007101700000) . 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

Tools Required

  1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(ref-267956-S32146669372007101700000) .
  2. J 42401 Radiator Cap/Surge Tank Test Adapter. See «Special Tools»(ref-267956-S32146669372007101700000) .
  1. Remove the pressure cap.
  2. Test the operation of the pressure cap. Refer to «Pressure Cap Testing»(ref-267956-S11170310982007101700000) .
  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. See «Special Tools»(ref-267956-S32146669372007101700000) . 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.

More articles — Engine Cooling System