Hi all had a check engine light come on today, got the code P2181 which is for coolant I checked the reserver tank it shows between min and max at hot temperture, My question is should it be hot or cold for the min and max lines be used?

 

P2181-COOLING SYSTEM PERFORMANCE

When Monitored:
Ignition on, Engine running, and no ECT DTCs present.

Set Condition:
PCM recognizes that the ECT has failed its self coherence test. The coolant temp should only change at a certain rate, if this rate is too slow or too fast this fault will set. Two trip fault. Three good trips to clear MIL. The MIL and ETC light will illuminate.


Possible Causes:

LOW COOLANT LEVEL

ECT SIGNAL CIRCUIT SHORTED TO VOLTAGE

ECT SIGNAL CIRCUIT OPEN

SENSOR GROUND CIRCUIT OPEN

ECT SIGNAL CIRCUIT SHORTED TO GROUND

ECT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

THERMOSTAT

ECT SENSOR

POWERTRAIN CONTROL MODULE (PCM)

 

Thanks for that info.

Bill

 

I actually just posted the same issue. Let me k ow what you find out. I got this code today.

 

His solution may not help you, as you are getting quite a few other codes, some unrelated, at the same time.

 

9 times out of ten a thermostat will fix this problem.

 

Well I cleared out the code and it has not happened again, not sure what caused it.

 

Thermostat codes will usually show back up in a couple days. Hope it stays off for you though.

 

mostlikely a t-stat prob. rarely an ect issue.
If I were in your shoes I would also be makin sure I replace the t-stat with an OEM t-stat. JMO.