Reading true coolant temp in cluster

[EB85]

I was fiddling with my car today because I was tired of not doing anything about it after it overheated about a month back. She ended up taking about a half gallon of coolant between the degas bottle and the crossover and I still wasn't done. I heat cycled it a couple times during the burp process and by the end it was still taking small amounts of AF but not like at first when it gulped it. My question is this: how do you get the cluster to read in diagnostic mode to see true coolant temp? I read you depress the odometer knob with the car in key on, engine off but all I kept getting was the trip meter.

 

[UncleSAm]

http://www.mustangworld.com/ourpics/News/99hec.htm

 

[01cobravortech]

I can tell you that the OBD II gauge cluster has confirmed each time that I was overheating.

People say its not accurate, but I see the temp readings fluctuating all the time. Saw it hit 107C the last time when I sputtered towards my driveway and was splashing coolant everywhere.

So yea its not reliable, but it is.

At least for coolant readings lol

 

[EB85]

I can tell you that the OBD II gauge cluster has confirmed each time that I was overheating.

People say its not accurate, but I see the temp readings fluctuating all the time. Saw it hit 107C the last time when I sputtered towards my driveway and was splashing coolant everywhere.

So yea its not reliable, but it is.

At least for coolant readings lol

That's kinda what I thought, too. I was able to see it fluctuate slightly on cold days when the t-stat would open and close. Obviously any aftermarket gauge is usually more accurate than an OEM reading but they are still there for a reason.