Bypass temp sensor

code p 0030 refers to heated oxygen sensor (HO2S) 1 bank 1 -heater control-circuit malfunction
code p 0039 refers to turbo/super charger bypass valve , control circuit --range /performance problem===causes --wiring--- bypass valve
code p 74 refers to outside air temperature sensor--circuit intermittent===causes ---wiring---poor connection---out side air temp sensor---ECM
code p 0098 refers to intake air temp (IAT) sensor 2 --circuit high input===causes --wiring short to positive ---IAT sensor---ECM

Om most vehicles, you can't. The coolant temperature sensor sends a variable signal to the ECM based on coolant temp, and that value is used by the ECM in the computation of the fuel mix (rich/lean) to the injectors. Without it, the vehicle will run poorly, if at all, and will set the Check Engine Light. There MAY be a separate coolant sensor that simple controls the radiator fan. This one could be bypassed, but that comes with great risk of engine overheating and damage. Most newer cars use the coolant temp sensor for both the fuel mix and the radiator fan with the fan on/off signal controlled by the ECM.

if you replaced the temp sensor and it still does that check to see if you didnt short the wires if all ok sounds like pcb board

wow intermittants are tough to find , the only way ive ever been sucessfull at it is to temp bypass each sensor (lie to controller) to see if it continues to run ,I do not recomend leaving any thing bypassed and not physicaly monitoring it ,
this temp bypassing is for only the most experienced techs that know normal state of sensors and can simultate them with off machine items

Bad temp sensor

Does it shut off heater with lights and fan on or power off? Did you bypass the temp sensor or thermostat? If temp sensor that mounts above filter, see http://www.fixya.com/support/t15119324-comfort_zone_cz2011_heater_shuts_off .

Hi there,

The temperature gauge relies on readings from the Engine Coolant Temp (ECT) Sensor.

The ECT sensor is usually located on (or near) the thermostat/coolant housing.

Refer to component No. 8 (2.0L Engine):




Refer to component No. 9 (2.5L Engine) locate under bypass tube:



Hope this helps.


Cheers,

ON your car the temp sensor is located in the bypass tube.

Hello and welcome to FixYa!

If that's the case, I strongly suggest that you replace the coolant temp sensor. Looks like it's faulty and grounding the circuit. The car's computer can detect it that's why it won't start but once you disconnect it, it will for the coolant sensor is bypassed.

Hope this helps and thank you for using FixYa! Have a good one!

Bypassing the temp sensor may cause a FIRE!!! I don't recommend this.