So i had a buddy throw my truck on his brand spankin' new tester today to give me my codes. My abs light is on and my break light and when he plugged her in the reader couldn't even get a signal from the ABS. Besides the point...

When he ran for PCM codes one came up for the Coolant Temp Sensor.

When i got the truck the temp gauge didn't work. So i replaced the sensor. When i was in there i noticed that there were 2 Pigtails for the 1 sensor. So i plugged in the other one and the Gauge worked!

Because it threw a code i decided to maybe try and plug in the other pigtail again, the one where the gauge didn't work. The live feed from the tester said that the PCM thought the truck was running at -40 degrees (maybe why i am getting SH&##Y mileage), on the gauge pigtail, when i switched them the temp gauge stopped working but the reader had the truck running at +90 degrees (pretty much what my thermostat is rated for).

WTF ???????

Can anyone explain this to me? Is there a second sensor for the gauge to read? and why isn't my ABS responding??

 

Depending on the year of your truck there are 2 sensors. One runs the gauge and the other runs the PCM. If you're looking at the motor head on the one on the alternator side runs the gauge and the other the PCM.

 

Isn't one called a sensor and the other a sender?

 

The gauge sensor is behind the alternator, and the PCM's sensor is on the other side of the thermostat.

 

Thankyou so much!! I hate not having a gauge!