Question

this test will cover all the material you have learned in the last two weeks including engine technology, cooling and lubrication systems as well as induction and fuel injection.
1
multiple choice 1 point
all the following may cause the pcm to run the electric cooling fan on high except?
vehicle is moving over 60mph
ect reaches 110 degrees c
a/c refrigerant pressure exceeds 240psi
certain dtcs are set
2
multiple choice 1 point
a radiator has been replaced and now the customer complains of a poor idle. the technician notices erratic temperature readings from the ect while monitoring current data. what is the most likely cause?
collapsed upper radiator hose
radiator cap installed incorrectly
wrong coolant used
air in the cooling system

Explanation:

Question 1

Step1: Analyze each option

• When vehicle is moving over 60 mph, there is enough air flow for cooling, so PCM doesn't need to run fan on high.
• ECT (Engine Coolant Temperature) reaching 110 degrees C indicates high temp, fan runs on high.
• A/C refrigerant pressure exceeding 240 PSI (high pressure) may need fan for condenser cooling, fan runs on high.
• Certain DTCs (Diagnostic Trouble Codes) related to cooling may trigger fan high - speed.

Step1: Analyze each option

• Collapsed upper radiator hose would cause flow issues but not directly erratic ECT readings.
• Radiator cap installed incorrectly may cause pressure issues but not main cause of erratic ECT.
• Wrong coolant used may affect cooling efficiency but not as likely as air in system.
• Air in the cooling system can cause erratic coolant flow, leading to erratic ECT (Engine Coolant Temperature) readings.

Answer:

Vehicle is moving over 60 mph

Question 2