Scan master #s

[mr84ss]

Hey guys im having an wierd issue. Ok i just changed my water pump, thermostat(drill hole in it) and changed the coolant temp sensor. When i start the car from cold, scan master reads 60 degree. Ok when it reads 110, the fans kick on snd the SM teml starts reading 80,20,and then -29. The #s keep bouncing around,then the car idles up high and the fans stay on until i cut it off. It did this before i changed the water pump(was leaking), thermo and coolant sensor. What causes these issues?

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[Ernie GN]

I’m not the best person for this but I’ll help you with my own experience.

There is two sensors.
One is the coolant temp sensor.
other one is basically a switch for your fans but it also reads temperature.

Which one did you change ?

There is one intake on the top.
and the other one is down lower sideways pointing towards the radiator

 

[mr84ss]

I changed the one with the blk and yellow wires to the right of the thermostat(if you standing in front of the car)

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[Ernie GN]

The fan is controlled by the settings in your chip. But the computer gets information from the sensors.

 

[Ernie GN]

 

[Ernie GN]

You should start by checking in the voltage. At the connectors.

 

[mr84ss]

I changed the ecm sensor.
Ok, thanks for the info

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[Ernie GN]

I was getting low voltage on my yellow wire .
Ended up having to change the wire.
Two minutes after my car would start the fan will stay on and never Idled correctly.

My turbo tweak chip is set at 166 degrees for the fan switch.

 

[mr84ss]

I'll check 2morrow. Does it need to read 12v?

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[TurboBob]

check the ground wires at the back of the engine.

does any other data go strange on the scanmaster?

what MAF and air filter is on the engine?

try plugging the old sensor into the harness (without the sensor installed in the engine). measuring voltage is a good idea

Bob

 

[Ernie GN]

I'll check 2morrow. Does it need to read 12v?

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5v

 

[Ernie GN]

Black wire is your negative
yellow is your positive

Basically what happens if it’s raining less voltage there your car thinks it’s hot and makes the fan come on.

Voltage is not correct .
Trace the wire back by the firewall.if you could get it by the computer.
Cut it and check the voltage again.
If you get good voltage wire is bad.
If not there’s a possibility your computer is bad .

 

[TurboBob]

less than 5v with the sensor plugged in. 5v with it unplugged

 

[Ernie GN]

Turbo bob knows a lot more then me.

Listen to what he says as well

 

[mr84ss]

Ok thanks again. I'll check it 2morrow [emoji22]

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