Overheating help.. 2008 WJ 3.7L

[brodyhardman]

• 2008 Jeep Grand Cherokee 3.7 A few weeks ago I went to start my Jeep and it wouldn't even crank over so I thought my factory battery was finally bad. Bought a new battery and still the same problem. I tried to check fuses and nothing worked. Set for a few days and then started right up like nothing ever happened and so problem in that area since. But a week ago my Jeep started to overheat and then send a message "trans over temp". Parked it and got a new low coolant temp sensor, thermostat, and coolant. But still overheating and throwing the code P0117. Any info on each problem is appreciated. Thanks
  
  
  
  
  
  
  

 

[TerryMason]

Did you receive both the Trans over temp" message, as well as the engine overheating?
Were you low on coolant?


P0117
Engine Coolant Temperature (ECT) Circuit Low Input
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The ECT (Engine coolant temperature) sensor is a thermistor located in the engine block or other coolant passage. It changes resistance with changes in temperature of the coolant that it's in contact with. It's usually a two wire sensor. One wire is a 5 volt reference from PCM (Powertrain Control Module) and the other is a ground supplied from PCM.
As the temperature of the coolant changes, the resistance of the sensor changes. When the engine is cold, the resistance is high. When the engine is warm, the resistance is low. If the PCM detects a signal voltage lower than the normal operating range of the sensor then P0117 code will set.
[h=2]Symptoms[/h]Potential symptoms include:

• MIL (Malfunction Indicator Lamp) illumination
• Poor fuel economy
• Poor drivability
• Engine may run rough or blow black smoke out the tailpipe
• May not idle
• May start and then die

[h=2]Causes[/h]Potential causes of the P0117 code include:

• Bad ECT sensor
• Short to ground on ECT signal circuit
• Faulty or damaged connectors
• Wiring harness damaged
• Loose terminals at ECT or PCM
• POSSIBLY an overheated engine
• Bad PCM