Engine Cooling: Diagnosis Saab 9-7X I

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check 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 diagnostic trouble codes (DTCs) and their status

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

Scan Tool Output Controls

PCM - 4.2L, 5.3L

Scan Tool Data List

Powertrain Control Module (PCM) 4.2 L (LL8), 5.3L (LM4)

Instrument Panel Cluster

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

DTC P0480

Conditions for Running the DTC

1. The engine speed is greater than 400 RPM.
2. The ignition voltage is greater than 10 volts and less than 18 volts.

Conditions for Setting the DTC

1. The PCM detects that the commanded state and the actual state of the control circuit do not match.
2. The above condition is present for at least 5 seconds.

Action Taken When the DTC Sets

DTC P0480 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0480 is a Type B DTC.

Circuit/System Testing

1. Ignition OFF, disconnect the fan relay.
2. Measure between the fan relay ground circuit terminal and ground for less than 3 ohms. If more than the specified range, test the ground circuit for an open/high resistance.
3. Operate the engine at 2,000 RPM for 2 minutes. The fan should be quiet to indicated the clutch is disengaged. If not disengaged, test the cooling fan clutch supply voltage circuit for a short to voltage. If the circuit tests normal, replace the clutch.
4. Ignition OFF, install a 10A fused jumper wire between the positive terminal at the battery and the cooling fan clutch supply voltage circuit terminal.
5. Operate the engine at 2,000 RPM for 2 minutes. The fan should be loud to indicated the clutch is engaged. If not engaged, test the cooling fan clutch supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the clutch.
6. Ignition OFF, install a 10A fused jumper wire between the relay voltage supply circuit terminal and the cooling fan clutch supply voltage circuit terminal.
7. Operate the engine at 2,000 RPM for 2 minutes. The fan should be loud to indicated the clutch is engaged. If not engaged, test the relay 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.
8. Connect a test lamp between the positive terminal at the battery and the cooling fan clutch relay control circuit terminal.
9. Engine running at 2,000 RPM, command the cooling fan clutch from 10-80 percent. The test lamp should flash at approximately 2 Hz as its brightness varies from dim to bright. If the lamp does not flash or vary correctly, test the cooling fan clutch control circuit for a short to ground, a short to voltage, or an open/high resistance. If the circuit tests normal, replace the control module.
10. If all circuits and the control module test normal, replace the relay.

Component Testing

Relay Test

1. Connect the relay ground terminal to ground and the voltage supply terminal to appropriately fused power to energize the relay.
2. Test for less than 1 volt between the load voltage supply terminal and ground.
3. Connect the relay control circuit terminal to ground.
4. Test for B+ between the load voltage supply terminal and ground.

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

DTC P0483 or P0493

1. Ignition OFF, disconnect the fan relay.
2. Measure between the fan relay ground circuit terminal and ground for less than 3 ohms. If more than the specified range, test the ground circuit for an open/high resistance.
3. Operate the engine at 2,000 RPM for 2 minutes. The fan should be quiet to indicated the clutch is disengaged. If not disengaged, test the cooling fan clutch supply voltage circuit for a short to voltage. If the circuit tests normal, replace the clutch.
4. Ignition OFF, install a 10A fused jumper wire between the positive terminal at the battery and the cooling fan clutch supply voltage circuit terminal.
5. Operate the engine at 2,000 RPM for 2 minutes. The fan should be loud to indicated the clutch is engaged. If not engaged, test the cooling fan clutch supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the clutch.
6. Ignition OFF, install a 10A fused jumper wire between the relay voltage supply circuit terminal and the cooling fan clutch supply voltage circuit terminal.
7. Operate the engine at 2,000 RPM for 2 minutes. The fan should be loud to indicated the clutch is engaged. If not engaged, test the relay 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.
8. Connect a test lamp between the positive terminal at the battery and the cooling fan clutch relay control circuit terminal.
9. Engine running at 2,000 RPM, command the cooling fan clutch from 10-80 percent. The test lamp should flash at approximately 2 Hz as its brightness varies from dim to bright. If the lamp does not flash or vary correctly, test the cooling fan clutch control circuit for a short to ground, a short to voltage, or an open/high resistance. If the circuit tests normal, replace the control module.
10. Perform the relay component test. The relay should test normal. If the relay does not test normal, replace the relay.
11. Ignition OFF, disconnect the fan clutch at the shroud.
12. Measure between the low reference circuit terminal and ground for less than 3 ohms. If more than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
13. Ignition ON, measure between the 5-volt reference and the low reference circuit terminals for 4.8-5.2 volts. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module. If more than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
14. Install jumper wires in the 5-volt reference and low reference circuits between the harness and pigtail connectors at the shroud.
15. Measure DC voltage between the signal circuit terminal at the sensor pigtail connector and the 5-volt reference circuit jumper wire terminal.
16. Ignition ON, rotate the fan by hand. The voltage should toggle between approximately 5-0 volts. If the voltage does not toggle correctly, test the 3 circuits in the pigtail harness for a short to ground, a short to voltage, or an open/high resistance. If the circuits test normal, replace the clutch.
17. Leave the jumpers from the previous step in place. Measure voltage between the signal circuit terminals of the harness and pigtail connectors at the shroud.
18. Rotate the fan by hand. The voltage should toggle between approximately 5-0 volts. If the voltage does not toggle correctly, test the signal circuit for a short to ground, a short to voltage, or an open/high resistance. If the circuit tests normal, replace the control module.
19. If all circuits, the relay, and the speed sensor test normal, replace the clutch.

Relay Test

1. Connect the relay ground terminal to ground and the voltage supply terminal to appropriately fused power to energize the relay.
2. Test for less than 1 volt between the load voltage supply terminal and ground.
3. Connect the relay control circuit terminal to ground.
4. Test for B+ between the load voltage supply terminal and ground.

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

DTC P0495

1. The engine is running.
2. The system voltage is greater than 8.5 volts.
3. The intake air temperature (IAT) is greater than -7°C (+19°F).
4. Zero percent duty cycle is commanded, and the engine RPM has been over 1,800 RPM for at least 120 seconds.

The cooling fan RPM exceeds 1,600 RPM for 81 seconds.

DTC P0495 is a Type B DTC.

DTC P0495 is a Type B DTC.

1. Ignition OFF, disconnect the harness connector at the fan shroud.
2. Operate the engine at 2,000 RPM for 2 minutes. The fan should be quiet to indicate the clutch is disengaged. If disengaged, test or replace the relay. If not disengaged, test the cooling fan clutch supply voltage circuit for a short to voltage. If the circuit tests normal, replace the clutch.

Relay Test

1. Connect the relay ground terminal to ground and the voltage supply terminal to appropriately fused power to energize the relay.
2. Test for less than 1 volt between the load voltage supply terminal and ground.
3. Connect the relay control circuit terminal to ground.
4. Test for B+ between the load voltage supply terminal and ground.

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

DTC P0526

1. The engine is running.
2. The system voltage is greater than 8.5 volts.

1. The powertrain control module (PCM) has detected a loss of cooling fan speed signal.
2. The above condition is present for at least 11 seconds.

DTC P0526 is a Type B DTC.

DTC P0526 is a Type B DTC.

1. Ignition OFF, disconnect the fan clutch at the shroud.
2. Measure between the low reference circuit terminal and ground for less than 3 ohms. If more than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
3. Ignition ON, measure between the 5-volt reference and the low reference circuit terminals for 4.8-5.2 volts. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module. If more than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
4. Install jumper wires in the 5-volt reference and low reference circuits between the harness and pigtail connectors at the shroud.
5. Measure DC voltage between the signal circuit terminal at the sensor pigtail connector and the 5-volt reference circuit jumper wire terminal.
6. Ignition ON, rotate the fan by hand. The voltage should toggle between approximately 5-0 volts. If the voltage does not toggle correctly, test the 3 circuits in the pigtail harness for a short to ground, a short to voltage, or an open/high resistance. If the circuits test normal, replace the clutch.
7. Leave the jumpers from the previous step in place. Measure voltage between the signal circuit terminals at the harness and pigtail connectors at the shroud.
8. Rotate the fan by hand. The voltage should toggle between approximately 5-0 volts. If the voltage does not toggle correctly, test the signal circuit for a short to ground or a short to voltage. If the circuit tests normal, replace the control module.
9. If all circuits and the speed sensor test normal, replace the engine control module (ECM).

Relay Test

1. Connect the relay ground terminal to ground and the voltage supply terminal to appropriately fused power to energize the relay.
2. Test for less than 1 volt between the load voltage supply terminal and ground.
3. Connect the relay control circuit terminal to ground.
4. Test for B+ between the load voltage supply terminal and ground.

Circuit Description

The powertrain control module (PCM) uses the engine coolant temperature (ECT) sensor to monitor the engine for an over temperature condition. This condition occurs when the coolant temperature is above 132°C (270°F). When an over temperature condition is present, DTC P1258 will set. The PCM will disable 2 groups of 4 cylinders by turning OFF the fuel injectors. By switching between the 2 groups of cylinders, the PCM is able to reduce the temperature of the coolant.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P1258 Engine Coolant Overtemperature - Protection Mode Active

1. DTCs P0117, P0118, P1114, and P1115 are not active.
2. The engine is running.

The engine coolant temperature is above 132°C (270°F) for 10 seconds or more.

1. The PCM will illuminate the malfunction indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
2. The PCM will signal the instrument panel cluster (IPC) to turn ON the Service Engine Soon indicator.
3. The PCM will alternately disable 2 groups of 4 cylinders by turning OFF the fuel injectors.
4. The PCM will store conditions which were present when the DTC set as Freeze Frame and File Records data.

Conditions for Clearing the MIL/DTC

1. The PCM will turn the MIL OFF after 3 consecutive trips that the diagnostic has been run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

DTC P1258

The powertrain control module (PCM) uses the cooling fan speed signal in order to determine the actual fan speed in relation to the desired fan speed. The PCM uses the cooling fan speed signal in order to reduce the cooling fan noise and in order to maintain the powertrain cooling requirements. The PCM supplies power and ground to the clutch hall effect sensor of the cooling fan clutch. The hall effect sensor returns a signal pulse through the speed signal circuit in response to the reluctor track, which is located inside the fan clutch. If during operation, the PCM detects a loss of the cooling fan speed signal, DTC P1481 will set.

This diagnostic procedure supports the following DTC

DTC P1481 Cooling Fan Speed Sensor Circuit

1. The engine is running.
2. System voltage is greater than 8.5 volts.

1. The PCM has detected a loss of cooling fan speed signal.
2. The above condition is present for at least 11 seconds.

1. The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
2. The PCM will store the condition as Freeze Frame/Failure Records data.
3. The PCM commands the cooling fan clutch to 100 percent.

1. The PCM turns OFF the MIL after the third consecutive trip that the diagnostic test has run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. Clear the DTC by using the Clear DTC Information function of the scan tool.

Diagnostic Aids

1. An inline connector could cause an intermittent DTC. Ensure to test for poor connections and pin retention at all inline connectors. Refer to system schematics for connector and locations.
2. If the condition is not present, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-268113-S21569870072007101800000) .
3. Disconnect the harness connector of the cooling fan clutch from the shroud. Inspect the exposed wires between the harness connector and the tubing.
4. Inspect the cooling fan clutch harness in order to ensure that the clutch supply voltage circuit is not shorted to the following circuits: The 5-volt reference circuit The cooling fan speed signal circuit The low reference circuit
5. DTC P1481 will set if the engine is started without the drive belt ON.

The powertrain control module (PCM) sends a pulse width modulation (PWM) signal of 0-12 volts via the cooling fan clutch control circuit to the cooling fan relay. The PCM uses this PWM to control the position of the oil control valve located inside the cooling fan clutch. If during operation, the PCM detects an improper circuit condition on the cooling fan clutch control circuit DTC P1482 will set.

This diagnostic procedure supports the following DTC

DTC P1482 Cooling Fan Speed Output Circuit

System voltage is greater than 8.5 volts.

1. An improper voltage level has been detected on the cooling fan clutch control circuit.
2. The above condition is present for at least 6 seconds.

1. The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
2. The PCM stores the conditions present when the DTC sets as Freeze Frame/Failure Records data.
3. The PCM commands the cooling fan clutch to 100 percent.

1. The PCM turns OFF the MIL after the third consecutive trip the diagnostic has run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

1. An inline connector could cause an intermittent DTC. Ensure to test for poor connections and pin retention at all inline connectors. Refer to system schematics for connector and locations.
2. If the condition is not present, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-268113-S21569870072007101800000) .
3. Disconnect the harness connector of the cooling fan clutch from the shroud. Inspect the exposed wires between the harness connector and the tubing.

The cooling fan relay sends a pulse width modulation (PWM) signal of 12-14 volts to the cooling fan clutch through the cooling fan clutch supply voltage circuit. The powertrain control module (PCM) uses this PWM signal in order to control the speed of the cooling fan clutch. The signal controls the position of the oil control valve inside the cooling fan clutch. If the cooling fan RPM is different than the PCM is expecting, DTC P1484 will set. The actual cooling fan RPM vs the desired cooling fan RPM is not always exactly the same. There can be up to an 800 RPM difference.

This diagnostic procedure supports the following DTC

DTC P1484 Cooling Fan System Performance

1. The engine is running.
2. The system voltage is greater than 8.5 volts.
3. The intake air temperature (IAT) is greater than -7°C (+19°F).
4. DTCs P1481 and P1482 are not set.
5. The engine speed is less than 3,200 RPM.
6. The engine speed is not changing more than 250 RPM for 5 seconds.
7. Fan command is greater than 0 percent.

1. The maximum allowable error of 1,000 RPM in the cooling fan speed occurs for 100 seconds.
2. The PCM detects that the cooling fan clutch is locked up.

1. The Reduced Engine Power indicator illuminates only if the PCM detects that the cooling fan clutch is locked up.
2. The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
3. The PCM will store the conditions as Freeze Frame/Failure Records data.
4. The PCM commands the cooling fan clutch to 100 percent.

1. Use the Clear DTC Information function on the scan tool.
2. Perform an ignition key cycle.

The PCM turns OFF the MIL after the third consecutive trip that the diagnostic test has run and passed.

The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

1. An inline connector could cause an intermittent DTC. Ensure to test for poor connections and pin retention at all inline connectors. Refer to system schematics for connector and locations.
2. If the condition is not present, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-268113-S21569870072007101800000) .
3. Disconnect the harness connector of the cooling fan clutch from the shroud. Inspect the exposed wires between the harness connector and the tubing.
4. If DTCs P1484 and P0113 are set, and the weather conditions are cold, the cooling fan code may be false. Clear DTC P1484, and after an IAT sensor check, allow the DTC to reset.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Cooling System. Refer to «Checking Aftermarket Accessories»(ref-268113-S34470778152007101800000) .
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. «Engine Coolant Temperature Indicator Always On»(ref-268147-S17076507822007101800000)
2. «Engine Overheating»(ref-268147-S07711918002007101800000)
3. «Loss of Coolant»(ref-268147-S19557439092007101800000)
4. «Thermostat Diagnosis»(ref-268147-S24283996712007101800000)
5. «Coolant Heater Inoperative»(ref-268147-S08237598182007101800000)
6. «Engine Fails To Reach Normal Operating Temperature»(ref-268147-S15843936092007101800000)
7. «Excessive Fan Noise»(ref-268147-S17976960922007101800000)

Thermostat Diagnosis

Thermostat Diagnosis

1. Test the engine coolant heater for an open or short to ground. If open or shorted, replace the heater.
2. If the heater tests normal, replace the coolant heater power cord.

Pressure Cap Testing

Tools required

1. J 24460-01 Cooling System Pressure Tester. See «Special Tools»(ref-268147-S09851013102007101800000) .
2. J 42401 Radiator Cap / Surge Tank Test Adapter. See «Special Tools»(ref-268147-S09851013102007101800000) .

Scheme 4

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-268147-S09851013102007101800000) .
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-268147-S09851013102007101800000) . 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.

The electro-viscous clutch is controlled by the powertrain control module (PCM). The PCM controls a solenoid that regulates a fluid pressure that controls slip of the fan clutch. Internal to the fan is a centrifugal fluid pump, solenoid, hall effect sensor, valve lever, and hydraulic fluid. There are 2 chambers for the fluid. These 2 chambers are separated by a valve lever. The first chamber is the storage chamber, which holds excess fluid. The second chamber is the working chamber. As the pressure of the fluid is increased in the working chamber, the amount of slip the fan has is decreased. The position of the valve lever is controlled by an electric solenoid.

1. Turning OFF the engine when the cooling fan clutch is engaged, the cooling fan clutch will be engaged at engine restart. This may cause an excessive noise concern. This is a normal condition.
2. If the engine is turned OFF for an extended period of time, usually over night, the hydraulic fluid may fill working chamber and cause limited slip at engine restart. This may cause the excessive noise condition. This is a normal condition.
3. To engage the cooling fan clutch, it can take up to 2 minutes for a 100 percent command with the engine at 2,000 RPM. The lower the engine speed, the longer it will take the cooling fan clutch to engage.
4. To disengage the cooling fan clutch, it can take up to 2 minutes with the engine at 2,000 RPM. The lower the engine speed, the longer it will take to disengage.
5. In lower ambient air temperatures the cooling fan clutch will engage in less time, however it will take longer to disengage.
6. An inline connector could cause an intermittent DTC. Ensure to test for poor connections and pin retention at all inline connectors. Refer to system schematics for connector and locations.
7. If the condition is not present, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-268113-S21569870072007101800000) .