最近发现自己的06 Honda Odyssey(270 K 公里）在等红灯时overheating when AC Not on，车载OBDII蓝牙App showing coolant 温度读数可到96C or even higher , 但是radiator cooling fan and condensor fan 都不启动; put AC on, (AC working properly without issues), both Radiator and condensor fans are on low speed immidiately，cooling down the Coolant termparature to normal 85- 87c, this is how i am doing now to keep my engine from overheating again.
my diagnose logic is: If both Fans are on when AC on, can we say the Fans' raleys/ fuses, Fans motor and wiring are all good? no matter if low speed or high speed are required? if so, should the CTSs(Coolant temparature sensors, 2 of them in upper and lower hoses) be the culpits which not functioning properly to close the loop to send signals to Raley to trigger the high speed fans? as there are two CTSs, one is on Thermostat housing to Upper hose (hot coolant out of engine), another one is close to lower hose back in engine, which one is controling the highspeed fans to kick-in when Coolant is over 90C? or both? if the CTSs are bad, how could the 车载OBDII蓝牙App still have a reading? or the reading is irrelavant to the switch on/off?
One more thing might need to add into consideration, I was adding in a transmission cooler two years ago in front of the radiator to cool down ATF to tow a small trailer, working fine, but not this year, no towing.
forgot to mention, i had cleanning radiator fins two years ago after remove the bumper to add in an aftermarket transmission cooler, coolant is Honda brand, viewed as "high quality".
sorry for confusion, "Overheating" for me is when Temp keep
climbing without stop, and as for the old car, i would think it is not normal without the ECM intervening such as cooling fan start blowing air when Temp keep rising. as monitoring closely, i was able to turn on AC to start the fans to keep it from really overheating causing a engine failure
足版，the coolant changed when i bought it from previous owner
Also checked coolant level, radiator cap and reservior level, all seems in good condition, no obviously coolant loosing. color still in blue clear transparent condition. as i am checking engine coolant temp from daily driving, this is all happend recently, coolant temp keep climbing when in stop without fans kicked in; so try to do a pre-cautious diagnose to prevent any disaster engine overheating
Yes, thanks for the idea--it will narrow down the issue
to either the signal device--CTS， 2of them, not sure which one yet, or the physical circuit to kick on Cooling fan, as Fan motor had been approved working fine as AC on had triggered the Fans on in low speed.
最近发现自己的06 Honda Odyssey(270 K 公里）在等红灯时overheating when AC Not on，车载OBDII蓝牙App showing coolant 温度读数可到96C or even higher , 但是radiator cooling fan and condensor fan 都不启动; put AC on, (AC working properly without issues), both Radiator and condensor fans are on low speed immidiately，cooling down the Coolant termparature to normal 85- 87c, this is how i am doing now to keep my engine from overheating again.
my diagnose logic is: If both Fans are on when AC on, can we say the Fans' raleys/ fuses, Fans motor and wiring are all good? no matter if low speed or high speed are required? if so, should the CTSs(Coolant temparature sensors, 2 of them in upper and lower hoses) be the culpits which not functioning properly to close the loop to send signals to Raley to trigger the high speed fans? as there are two CTSs, one is on Thermostat housing to Upper hose (hot coolant out of engine), another one is close to lower hose back in engine, which one is controling the highspeed fans to kick-in when Coolant is over 90C? or both? if the CTSs are bad, how could the 车载OBDII蓝牙App still have a reading? or the reading is irrelavant to the switch on/off?
One more thing might need to add into consideration, I was adding in a transmission cooler two years ago in front of the radiator to cool down ATF to tow a small trailer, working fine, but not this year, no towing.
thanks!
Most experts agree that your engine should run between 195 F degrees and 220 F degrees.
Check the radiator fan switch to cooant temperature sensor circuit.
forgot to mention, i had cleanning radiator fins two years ago after remove the bumper to add in an aftermarket transmission cooler, coolant is Honda brand, viewed as "high quality".
but as it is old car, i use OBDII app to monitor all parameters.
will check if the circuit is doing the job. thanks for inputs
指针接近H，或亮水温红灯，要停车检查是否漏水少水。每三年更换原厂冷却液能保持整个循环系统内十分干净，无腐蚀无锈蚀无水垢，发动机很Happy。
所谓96C过热没有原厂技术参数的支持，两个ECTs中那个底端管上的温感器是控制散热扇的，节温器上的温感器和散热扇控制无关.
至于加装散热器是否降低散热性能，那也只是和散热效率有关，可控制无关。
顺便说一嘴，我的德车108C以内为引擎正常工作温度范围，仪表盘也没有温度显示，从来也没有用OBD工具实测过，但预置过热预警和报警两重警告提示！
climbing without stop, and as for the old car, i would think it is not normal without the ECM intervening such as cooling fan start blowing air when Temp keep rising. as monitoring closely, i was able to turn on AC to start the fans to keep it from really overheating causing a engine failure
Also checked coolant level, radiator cap and reservior level, all seems in good condition, no obviously coolant loosing. color still in blue clear transparent condition. as i am checking engine coolant temp from daily driving, this is all happend recently, coolant temp keep climbing when in stop without fans kicked in; so try to do a pre-cautious diagnose to prevent any disaster engine overheating
你描述的是正常现象。
可以做个测试，模仿等红灯，正常工作温度下，原地怠速，不开空调，不开热风，加油门，让发动机转速上去，观察车内温度显示，观察风扇何时启动，同时也看着OBD2上的温度。
如果车里温度表显示升到了3/4而风扇一直没有启动，那就有问题了。
温度没有过高。红绿灯前没有流通空气，温度过高。
拨下两个CTS/Thermo fan switch, 把fan一端的插头短路看fan转不转，你甚至连车都不用打着，也甭管车有多热多冷，如果转就是TCS坏了。
那是正常工作温度。
电脑根本没办法验证它开关与否和温度的关系对不对。
https://www.docmotorworks.com/what-temp-should-my-fan-kick-in/
我的Accord有两个temperature sensors。dashboard上看到的是其中一个sensor的结果。另外一个sensor的数据用来控制电扇等等。换一个sensor十块钱，可以试一试。
https://bbs.wenxuecity.com/auto/529736.html
按照引擎的设计，Threashold90多度冷却风扇应该自动介入，而几次观察，风扇未启动，所以开始琢磨是哪的症结，当个乐子，
自从DIY，常来逛一逛，收益颇多，非常同意有的放矢，诊断为主的思路
所以还未将THERMOSTAT纳入考量, 费用和别的更不是考量范围，图的就是确诊症结，明析原理，对症下药
to either the signal device--CTS， 2of them, not sure which one yet, or the physical circuit to kick on Cooling fan, as Fan motor had been approved working fine as AC on had triggered the Fans on in low speed.
and another problemis Fan not on when Engine Threashold TEMP 93-95C is identified.
你的问题的根源就是你非要折腾，接了个OBD2要看看车咋样了。
没有那个OBD2，你看不出车子有任何不正常的现象。
Your problem is now the latter failed.
车里有水温显示，等显示升高了再行动不迟。