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Message: Re: Here's An Owner's Manual....
Changed By: whall
Change Date: August 15, 2011 01:46PM
Re: Here's An Owner's Manual....
Change Date: August 15, 2011 01:46PM
Re: Here's An Owner's Manual....
Here's how the engine compartment temperature system works....based on a 996. I just can't seem to find the time/temperature values for a 986. However, the system logic is the same.
[i]Engine Compartment Fan
To reduce the temperature of the engine compartment, a fan actuated by the DME control unit is installed under the engine compartment cover. If the fan is active, fresh air is fed into the engine compartment.
Functioning
1- With engine running or ignition on:
If the engine temperature is higher than 102 degrees C combined with the engine compartment temperature being higher than 60 degrees C, the engine compartment fan is switched on for 30 seconds by the DME control unit ventilating the engine compartment. The fan will only operate for 100 seconds with the ignition on.
2- With the engine not running and ignition switched off:
If the engine compartment temperature is higher than 60 degrees C, the DME control remains active for 20 minutes. If the engine compartment temperature increases to about 85 degrees C, the fan will come on for 30 seconds. If the engine compartment temperature falls below 80 degrees C, the DME will turn off the system.
If, at the end of the original operation period (30 seconds), the engine compartment temperature is still higher than 85 degrees C, the engine compartment fan is started and runs for another 30 seconds. If the temperature still doesn't drop below 85 degrees C, a pause lasting 10 seconds occurs. Now the fan will start a third time. If, after 25 seconds the engine compartment still hasn't dropped below 80 degrees C a fault is registered and the cooling level warning light begins to flash and the "failure of engine compartment blower" legend on the ODC display illuminates.
The fan will continue to run until the programmed time has expired (20 min.) or until the next engine start after which the fan can run for 100 more seconds.[/i]
Now, with a P1157 code - engine compartment temperature sensor "short to ground" - it seems plausible to me that the system may be seeing a situation where it thinks that the engine compartment is too hot and eventually illuminates a flashing red light on the coolant temperature gauge and the "Failure of Engine-Compartment Blower".notice on the OBC display. Further, if a person was unduly worried, after reading and/or hearing about catastrophic engine failures, about the health of his or her own engine, perhaps the OBC message could be interpreted as: Engine Failure b-Lower.
In any event, I am going to my dealer later today to pick up some tires for my son's car and will pass this by the technicians for their evaluation of your situation. Also, make sure the technician(s) working on your car don't sell you a cure for a problem that doesn't exist, i.e., "Dealer has no other suggestions, other than an exploratory tear down."
It also seems strange to me that any qualified Porsche technician wouldn't be able to positively confirm or deny the existance of the OBC message you are relating to the Board and be able to point out the resolution to the message in a Porsche maintenance publication.
Bill
[i]Engine Compartment Fan
To reduce the temperature of the engine compartment, a fan actuated by the DME control unit is installed under the engine compartment cover. If the fan is active, fresh air is fed into the engine compartment.
Functioning
1- With engine running or ignition on:
If the engine temperature is higher than 102 degrees C combined with the engine compartment temperature being higher than 60 degrees C, the engine compartment fan is switched on for 30 seconds by the DME control unit ventilating the engine compartment. The fan will only operate for 100 seconds with the ignition on.
2- With the engine not running and ignition switched off:
If the engine compartment temperature is higher than 60 degrees C, the DME control remains active for 20 minutes. If the engine compartment temperature increases to about 85 degrees C, the fan will come on for 30 seconds. If the engine compartment temperature falls below 80 degrees C, the DME will turn off the system.
If, at the end of the original operation period (30 seconds), the engine compartment temperature is still higher than 85 degrees C, the engine compartment fan is started and runs for another 30 seconds. If the temperature still doesn't drop below 85 degrees C, a pause lasting 10 seconds occurs. Now the fan will start a third time. If, after 25 seconds the engine compartment still hasn't dropped below 80 degrees C a fault is registered and the cooling level warning light begins to flash and the "failure of engine compartment blower" legend on the ODC display illuminates.
The fan will continue to run until the programmed time has expired (20 min.) or until the next engine start after which the fan can run for 100 more seconds.[/i]
Now, with a P1157 code - engine compartment temperature sensor "short to ground" - it seems plausible to me that the system may be seeing a situation where it thinks that the engine compartment is too hot and eventually illuminates a flashing red light on the coolant temperature gauge and the "Failure of Engine-Compartment Blower".notice on the OBC display. Further, if a person was unduly worried, after reading and/or hearing about catastrophic engine failures, about the health of his or her own engine, perhaps the OBC message could be interpreted as: Engine Failure b-Lower.
In any event, I am going to my dealer later today to pick up some tires for my son's car and will pass this by the technicians for their evaluation of your situation. Also, make sure the technician(s) working on your car don't sell you a cure for a problem that doesn't exist, i.e., "Dealer has no other suggestions, other than an exploratory tear down."
It also seems strange to me that any qualified Porsche technician wouldn't be able to positively confirm or deny the existance of the OBC message you are relating to the Board and be able to point out the resolution to the message in a Porsche maintenance publication.
Bill
Original Message
Author: whallDate: August 15, 2011 01:31PM
Re: Here's An Owner's Manual....
Here's how the engine compartment temperature system works....based on a 996. I just can't seem to find the time/temperature values for a 986. However, the system logic is the same.
[i]Engine Compartment Fan
To reduce the temperature of the engine compartment, a fan actuated by the DME control unit is installed under the engine compartment cover. If the fan is active, fresh air is fed into the engine compartment.
Functioning
1- With engine running or ignition on:
If the engine temperature is higher than 102 degrees C combined with the engine compartment temperature being higher than 60 degrees C, the engine compartment fan is switched on for 30 seconds by the DME control unit ventilating the engine compartment. The fan will only operate for 100 seconds with the ignition on.
2- With the engine not running and ignition switched off:
If the engine compartment temperature is higher than 60 degrees C, the DME control remains active for 20 minutes. If the engine compartment temperature increases to about 85 degrees C, the fan will come on for 30 seconds. If the engine compartment temperature falls below 80 degrees C, the DME will turn off the system.
If, at the end of the original operation period (30 seconds), the engine compartment temperature is still higher than 85 degrees C, the engine compartment fan is started and runs for another 30 seconds. If the temperature still doesn't drop below 85 degrees C, a pause lasting 10 seconds occurs. Now the fan will start a third time. If, after 25 seconds the engine compartment still hasn't dropped below 80 degrees C a fault is registered and the cooling level warning light begins to flash and the "failure of engine compartment blower" legend on the ODC display illuminates.
The fan will continue to run until the programmed time has expired (20 min.) or until the next engine start after which the fan can run for 100 more seconds.[/i]
Now, with a P1157 code - engine compartment temperature sensor "short to ground" - it seems plausible to me that the system may be seeing a situation where it thinks that the engine compartment is too hot and eventually illuminates a flashing red light on the coolant temperature gauge and the "Failure of Engine-Compartment Blower".notice on the OBC display. Further, if a person was unduly worried, after reading and/or hearing about catastrophic engine failures, about the health of his or her own engine, perhaps the OBC message could be interpreted as: Engine Failure b-Lower.
In any event, I am going to my dealer later today to pick up some tires for my son's car and will pass this by the technicians for their evaluation of your situation. Also, make sure the technician(s) working on your car don't sell you a cure for a problem that doesn't exist, i.e., "Dealer has no other suggestions, other than an exploratory tear down."
Bill
[i]Engine Compartment Fan
To reduce the temperature of the engine compartment, a fan actuated by the DME control unit is installed under the engine compartment cover. If the fan is active, fresh air is fed into the engine compartment.
Functioning
1- With engine running or ignition on:
If the engine temperature is higher than 102 degrees C combined with the engine compartment temperature being higher than 60 degrees C, the engine compartment fan is switched on for 30 seconds by the DME control unit ventilating the engine compartment. The fan will only operate for 100 seconds with the ignition on.
2- With the engine not running and ignition switched off:
If the engine compartment temperature is higher than 60 degrees C, the DME control remains active for 20 minutes. If the engine compartment temperature increases to about 85 degrees C, the fan will come on for 30 seconds. If the engine compartment temperature falls below 80 degrees C, the DME will turn off the system.
If, at the end of the original operation period (30 seconds), the engine compartment temperature is still higher than 85 degrees C, the engine compartment fan is started and runs for another 30 seconds. If the temperature still doesn't drop below 85 degrees C, a pause lasting 10 seconds occurs. Now the fan will start a third time. If, after 25 seconds the engine compartment still hasn't dropped below 80 degrees C a fault is registered and the cooling level warning light begins to flash and the "failure of engine compartment blower" legend on the ODC display illuminates.
The fan will continue to run until the programmed time has expired (20 min.) or until the next engine start after which the fan can run for 100 more seconds.[/i]
Now, with a P1157 code - engine compartment temperature sensor "short to ground" - it seems plausible to me that the system may be seeing a situation where it thinks that the engine compartment is too hot and eventually illuminates a flashing red light on the coolant temperature gauge and the "Failure of Engine-Compartment Blower".notice on the OBC display. Further, if a person was unduly worried, after reading and/or hearing about catastrophic engine failures, about the health of his or her own engine, perhaps the OBC message could be interpreted as: Engine Failure b-Lower.
In any event, I am going to my dealer later today to pick up some tires for my son's car and will pass this by the technicians for their evaluation of your situation. Also, make sure the technician(s) working on your car don't sell you a cure for a problem that doesn't exist, i.e., "Dealer has no other suggestions, other than an exploratory tear down."
Bill