Help with engine compartment fan operation

[obthomas]

2003 Boxster S.

The engine compartment fan comes on to cool the engine compartment. It is controlled by a temperature switch located in the intake manifold. Normally the fan just starts and stops by this switch.

If the fan is not effective enough it will cause the LEDs to flash in the cluster temperature gauge. (Same LEDs as low coolant.)

Does anyone know the criteria the computer is looking for to keep the flashing LEDs off?

Thanks

[JFP in PA]

Four functions of the coolant warning light:

1. Engine coolant level too low

— light flashes slowly (0.5 Hz)

2. Engine compartment temperature too high

— light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)

3. Engine coolant temperature too high

— light is lit; pointer on the right

4. Temperature sensor at water outlet faulty

— light flashes rapidly (1 Hz); pointer on the right

Note

The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously

(1Hz = 1 flash per second. 0.5Hz = 2 seconds per flash)

[obthomas]

Thanks Jeff
My question goes beyond the boilerplate. Let me explain, My Porsche ECU is functional but has no engine to control. The car's engine has been replaced with an LS3. All of the Porsche temperature sensors are absent except for ambient air and the coolant temperature sensor which is now in the coolant of the LS3. The flashing LEDs still come on when the coolant is low and turn off when the coolant is full, however sometimes the flashing LEDs appear when the coolant is at operating temperature and the fans are on. They go off when the car is shut off and cools down a bit. I was thinking of the engine compartment fan causing the LEDs but I may have answered my own question here since I now realize that the engine room fan in my car is no longer monitored by the Porsche ECU. I guess I forgot I made the fan independent with its own temperature on/off switch in the coolant of the LS. So it must be that the LS runs a little hotter than Porsche and I am getting flashing LEDs because of that.

[obthomas]

Just to close this thread. Turns out the Porsche ECU/temperature system is sensing the Chevy engine temperature and transmitting that temperature by CAN to the instrument cluster gauge. If you are familiar with the Chevy steam vent system you will know that it is easy to get air around the temperature sensor and run hot if not connected properly. So this is what was happening to me and the flashing LED lights are a result of slight overheating. Everything is working as expected now. Lights had nothing to do with the engine compartment fan.