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Home >> Saab >> 1998 >> 900 SE Convertible L4-1985cc 2.0L DOHC Turbo EFI >> Repair and Diagnosis >> Engine, Cooling and Exhaust >> Cooling System >> Testing and Inspection >> Component Tests and General Diagnostics >> Check Cooling System Function

Check Cooling System Function






RADIATOR FAN
1. Connect Intellegent Saab Tester (ISAT) and select "READ FAULT CODES" on the menu.
2. To start the radiator fan, select "ACTIVATE RELAY" on the menu followed by "RADIATOR FAN, LOW".
- If the car is equipped with a 2-speed radiator fan, select "ACTIVATE RELAY" followed by "RADIATOR FAN, LOW".
- If the radiator fan does not work, check that there is 12 V on connection 30 on the relay holder for each radiator fan relay.
3. Strap between connections 30 and 87 in the relay holder.
- If the radiator fan works, the fault is in the relay. Install a new relay.
- If the radiator fan does not work, continue with point 4.





4. Disconnect the radiator fans connector and check that there is:
- 12 V between pin 1 and a safe grounding point.
- A resistance which is less than 1 Ohm between pin 2 and a safe grounding point
5. If that is not the case, check the wiring for short/open circuits between connection 87 on the relay holder and connector 1 on the radiator fan.
6. If the fan does not work in spite of these checks, replace the radiator fan.

PRESSURE SWITCH A/C
1. Connect the ISAT and select "OBTAIN READOUTS" followed by "PRESS SWITCH 1 A/C". for certain markets the car is equipped with an extra pressure switch, in which case select "PRESS SWITCH 2 A/C".

OPEN: The fan should not be activated.
CLOSED: The fan should be activated.

2. If this is not correct, disconnect the pressure switch and clamp between the connectors pins and repeat point 1.
3. If this does not work, connect a Break Out Box (BOB) and check the wiring for any open/short circuits as follows:





Pressure Switch 1
- Between connection 22 on the ICE and connection 3 on the pressure switch.
- Between connection 4 on the pressure switch and a safe grounding point.
Pressure switch 2
- Between connection 69 on the ICE and connection 1 of the pressure switch.
- Between connection 2 on the pressure switch and a safe grounding point.





THE TEMPERATURE IN THE COOLING SYSTEM
1. Connect ISAT and select "READ FAULT CODES" on the menu.
2. Check the temperature gauge in the main instrument by first selecting "ACT INSTR FUNGT" followed by "SIM.COOL.TEMP. 2" or "SIM.COOL.TEMP. 1".
- The ICE will now simulate a temperature in the cooling system between -30 and +130°C (-22 and +266°F) for 40 seconds.
- Read the temperature gauge in the car.
3. Connect a BOB and connect a voltmeter between connections 70 and 61 for main instrument 1 or between connections 70 and 14 for main instrument 2.
- Then select "ACT INSTR FUNCT" followed by "TEMP.GAUGE.OUT. 1 " or "TEMP.GAUGE.OUT. 2".
- The measured voltage should be:
- about 0 V at "ON"
- about 12 V at "OFF"





4. If the voltage is not correct, check the wiring for any open circuits/short circuits as follows:
- between connection 61 on the ICE and connection 4 on the main instrument (main instrument 1).
- between connection 14 on the ICE and connection 7 on the main instrument (main instrument 2).





5. If the cables are intact, the fault is probably in one of the control modules.
- Connect the ICE control module and repeat points 2 and 3 at the same tine as connection 4 (main instrument 1) or 7 (main instrument 2) is grounded.
- Measured voltage should be 0 V at "ON" and 12 v at "OFF".
- If the voltage is correct, the fault is probably in the main instrument, refer to Instrument Panel, Gauges and Warning Indicators.
- If the signal is faulty, refer to test values for ICE control module connections in Powertrain Management.





CHECKING THE IDLE SPEED INCREASE
1. Connect the ISAT and select "READ FAULT CODES" on the menu. If there are any diagnostic trouble codes refer to the diagnostic trouble code tables. Cooling System
2. Connect a BOB and measure with a voltmeter between connectors 10 and 70.
- Check the idling speed increase function by selecting "ACT OTHER FUNCT" on the menu followed by "IDLING INCREASE".





3. If it does not work, check the wiring between the ICE control module and the engine control system's control module (both control modules disconnected) for any open circuits/short circuits.
4. Connect the engine control system's control module and repeat point 2.
- The voltage should be 0 V at "ON" and 12 V at "OFF".
- If the voltage is correct, the fault is in the engine control system


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