Make your own free website on

Lecture outline that covered this topic was based on a handout and the following note in my lecture:

Page 25

A good temperature vs. voltage chart displaying the difference between the

two voltage curves inside the computer (the dual level temp sensor).


17.  Tech A and tech B are monitoring voltage on the coolant sensor of a SMEC equipped Chrysler.  They have checked the voltage cold (60 deg. F) and have found it to be at 3.00volts.  After leaving the vehicle running for a while and grabbing a cup of coffee, they return and recheck the engine temperature with a heat gun and find it at 160 deg (F)

To their amazement, they find the voltage on the coolant sensor now reads 3.2 volts.


Tech A says the coolant sensor must be faulty.  Tech B says the computer must be bad.

Who is correct? (3)

  1. A only  
  2. B only        
  3. both A & B                    
  4. neither A nor B


For two extra points, explain your answer: