A few questions on inputs and control.

[Ken Potter]

Hi,
I have a series of questions if there is someone who can answer them for me please.
1 If the water temp sensor is uhooked with the PCM use a default temp reading, if so what is this default temp? The motor still runs so it must default to somthing true?
2 What is the value of the resistors placed across the water temp sensor if I choose to bypass it and fake out the PCM. Restistors are rated in ohms, watts, ect true?
3. Same question as number 2 but in reguards to the air temp sensor?
4. I read where the PCM learns of bypassed sensors if we dont also include the switch. How fast does this PCm learn, in hrs of run time, min of run time, miles? Just how fast are we talking about here in a learning PCM?
5. If a water temp sensor is unplugged or even the air temp sensor, does the PCM use a default value when the inputs are unrealible? If so what are those defaults values?

Thanks in advance for answers on these questions. Maybe the specific questioins have never been looked into like the default values and such I dont know but hope so.

[gunman_sr5]

Look for Pots IAT/ECT Installation in the knowledge base section under D.I.Y. performance. Those 2 threads should explain what you are wanting to do.

[Ken Potter]

Hi Gunman,
No the posts do not get this specific especially with the question being asked of the default values. Im woundering if this has ever been researched.

[mechtech]

It will throw a code with them disconnected.
There are no default values. If there were, why would you want them???
The coolant and air sensors have related values - they read the same resistance at various temps.file:///C:/back%20up+drivers/Ford%20tech/Ford%20Fuel%20Injection%20%C2%BB%20Engine%20Coolan t%20Temperature%20Sensor%20(ECT).htm
Ford Fuel Injection » Engine Coolant Temperature Sensor (ECT)
This link will show you what's up.

[ZX2Fast]

Yeah, there is no preset value. The value changes with engine conditions. If you have the same reading all the time then it'll throw a PCM code. If you pick a value too high, the cooling fan won't come on and your engine will overheat.