My car has been throwing code 11 which is the Hondata code for overheating protection. The CEL comes on after the car has been running for a while (sometimes over an hour) and usually goes away if I turn off the engine and restart it. I am not sure if my car is actually overheating (because the temperature gauge never gets past half way), or if the ECU just thinks that it is. The overheating protection is set at 220 degrees in sManager. What sensor does the Hondata software get the temperature reading from? Is it the thermostat? Does anyone have any ideas of what I should check first? By the way, I have a p72 ECU with Hondata s300 if that matters. Thanks a lot!

 

The Engine Coolant Temperature sensor. 220 is pretty hot. Obviously you'd want to check that your fan is coming on like it should be and the rest of your cooling system for any possible issues.

 

I have my fan on a switch and manualy turn it on, so I know that it is working. Does the temperature gauge in the cluster also run off of the coolant temperature sensor? Maybe I should replace that sensor. Thanks for your help.

 

A b-series engine has 2 temp sensors in the head, a 2 wire and a single wire. The single wire sensor is for the cluster and the 2 wire sensor is for the ECU. The fans should be controlled by a thermo switch either in the radiator itself, or on the thermostat housing. Depending on the chassis the sensor for the cluster may need to be swapped from the original engine the car had in order for the cluster to read correctly. If the ECU is seeing over 220 you will get the over heating code....this is telling you there is a problem and need to correct it ASAP.

 

pm'd u i have the same problem

 

i have seen cars get hotter than 220 before the dash gauge even starts to move, so when it does move you know you have serious problems. as spunkster said, the ecu gets temp data from the 2-pin sesnor under the dizzy, in my experience its pretty accurate so i would look into the issue asap

 

i have the same exact problem as the op... the temp gauge on the cluster doesnt move up at all but after driving for like 20 mins the cel turns on... i have a 2000 civic si with a obd1 ecu... how do i know what to replace if it only comes on after driving for a while and if i shut off the car and turn it right back on it goes away...

 

Fan switch is handy...but do you know if your thermostat is opening? Cooling stagnant water/coolant does not do much in preventing your car from overheating...

 

if its anything like mine its got mud in the water jacket all i can say is keep flushing ur radiator and water jacket till u stop getting dirt in ur over flow