LS460 Readiness Code- P0125 insufficient Coolant Temp for Closed Loop Fuel Control L
03-02-19, 04:46 AM
#1
Driver School Candidate
Thread Starter
LS460 Readiness Code- P0125 insufficient Coolant Temp for Closed Loop Fuel Control L
this code is not showing up as a check engine light. It is only showing up under the enhanced scan with my scan tool under “Readyness test”
i noticed I have a lot of excessive exhaust from the tail pipes than all the other cars this time of year even after letting warm up. It only went away for a few min. After driving on 90 and parked but came back again after it sat and idled for about 10 min.
code says the temp is not getting hot enough to close fuel loop so I think I’m getting extra fuel vapor.
Had it at the dealer yesterday for a complete inspection for first time since I just purchased 2 days ago and they never pulled or said anything about that code.
I found it could be Low on Coolant (nope) - bad or dirty sensor- bad connection- stuck open thermostat or bad Ecm... (I don’t think it’s the latter)
i did have an air pocket in the radiator as I could hear water gargling in the glove box. The dealer put an air remover on during the inspection so that’s done. But code is still there...
can someone tell me has this happened to you?
Where is the Thermostat Located?
Where is the Ect Sensor located?
(Diagrams work best for me)
getting terrible fuel fuel economy and I am sure it’s because of this,
LS460 2010
i noticed I have a lot of excessive exhaust from the tail pipes than all the other cars this time of year even after letting warm up. It only went away for a few min. After driving on 90 and parked but came back again after it sat and idled for about 10 min.
code says the temp is not getting hot enough to close fuel loop so I think I’m getting extra fuel vapor.
Had it at the dealer yesterday for a complete inspection for first time since I just purchased 2 days ago and they never pulled or said anything about that code.
I found it could be Low on Coolant (nope) - bad or dirty sensor- bad connection- stuck open thermostat or bad Ecm... (I don’t think it’s the latter)
i did have an air pocket in the radiator as I could hear water gargling in the glove box. The dealer put an air remover on during the inspection so that’s done. But code is still there...
can someone tell me has this happened to you?
Where is the Thermostat Located?
Where is the Ect Sensor located?
(Diagrams work best for me)
getting terrible fuel fuel economy and I am sure it’s because of this,
LS460 2010
Last edited by LS460Lex; 03-02-19 at 04:51 AM. Reason: gramer correction
03-04-19, 01:16 AM
#3
Driver School Candidate
Thread Starter
No, no head gasket test. There may have been a radiator flush performed causing the air pocket.
im sure it’s this sensor not communication the proper temp to the car to close fuel loop and it’s causing a rich fuel burn. Or I should say I hope.
after I got off I90 to vapor went away for 10 min so that tells me it’s not head gasket because it would smoke more with higher rpms and vacuum and the smell would be sweet smelling.as well.
i think I’m going to replace thermostat and ect sensor. Do you know where they are located.? I read somewhere that the engine coolant temperature sensor can give bad reading to ECM and still send normal temp to the dash board reading.
im sure it’s this sensor not communication the proper temp to the car to close fuel loop and it’s causing a rich fuel burn. Or I should say I hope.
after I got off I90 to vapor went away for 10 min so that tells me it’s not head gasket because it would smoke more with higher rpms and vacuum and the smell would be sweet smelling.as well.
i think I’m going to replace thermostat and ect sensor. Do you know where they are located.? I read somewhere that the engine coolant temperature sensor can give bad reading to ECM and still send normal temp to the dash board reading.
05-02-19, 07:40 PM
#5
Driver School Candidate
Thread Starter
I have an 2010 LS460 that has me scratching my head. I get a little extra exhaust fumes when it’s cold compared to other peoples car even after the car is warmed up...
i DO NOT have a check engine light and there are NO codes in my current or historyMIL but what I do have and it does not seem to go away is A “Rediness Code” of P0300 & P0125.
I checked the thermostat and that was fine. I checked the EcT and that was fine as well but it seems I burn a lot of gas.
my fuel pressure from my scanner is 560 - 590 psi at idle and will go up to 1800 psi when I step on the gas.
i have a loud clicking noise coming from my Fuel Rail Pulsation Dampener.(FRPD)
could you tell me what my problem might be?
is it a bad (FRPD)
is it a bad (Fuel Pressure Regulator in the fuel pump)
is it a bad or lazy O2 sensor also called an Air Fuel Ratio Sensor
I heard P0125 is also a possible O2 sensor code.
Thanks so much
i DO NOT have a check engine light and there are NO codes in my current or historyMIL but what I do have and it does not seem to go away is A “Rediness Code” of P0300 & P0125.
I checked the thermostat and that was fine. I checked the EcT and that was fine as well but it seems I burn a lot of gas.
my fuel pressure from my scanner is 560 - 590 psi at idle and will go up to 1800 psi when I step on the gas.
i have a loud clicking noise coming from my Fuel Rail Pulsation Dampener.(FRPD)
could you tell me what my problem might be?
is it a bad (FRPD)
is it a bad (Fuel Pressure Regulator in the fuel pump)
is it a bad or lazy O2 sensor also called an Air Fuel Ratio Sensor
I heard P0125 is also a possible O2 sensor code.
Thanks so much
06-15-19, 12:03 PM
#6
Instructor
Just saw your PM from last month.
P0300 (Random / Multiple Cylinder Misfire): Simultaneous misfiring of several cylinders detected. Trouble areas: open/short in engine wire harness, vacuum hose connections, ignition system, injectors, fuel pressure, MAF, engine coolant temperature sensor, compression, valve clearance/timing, ventiliation hoses/valve, air intake system, ECM/ECU.
To troubleshoot this properly, look at the freeze-frame data, you may need Techstream to do this. When the misfire happens, the computer will store freeze-frame data, showing what every sensor is reading at that exact moment. The important things to look at are coolant temp, misfire rpm, misfire load, Short Term Fuel Trim, Long Term Fuel Trim (neither will be accurate if you recently reset the codes), fuel pump duty, STFT1+LTFT1, STFT2+LTFT2. Check all your ventilation hose connections. There are further tests you can do in Techstream to test the misfiring of port injection and direct injection. Your low-side fuel pressure rail should measure 196-588 kPa (28-85 psi). Fuel pressure sensor reading in Techstream should be 2000-5000kPa at idle, with A/C and all accessories off and engine fully warmed up. Fuel pressure pulsation damper could be faulty, 23270-38010 ~$110, or fuel pressure regulator 23280-38020 ~$155, or fuel pressure sensor 90980-11451. I think it's unlikely that it's the O2 sensor.
P0125 (Insufficient Coolant Temp for Closed Loop Fuel Control): Related to DTC P0115. Resistance of ECT (Engine Coolant Temp) sensor varies in proportion to actual ECT. After engine is started, ECT is monitored through ECT sensor. If ECT sensor indicated engine isn't warm enough for closed-loop fuel control, despite a specified period of time having elapsed since engine start, ECM interprets this as malfunction in ECT sensor or cooling system. The specified period of time depends on the starting engine coolant temperature (60 seconds at -14C or above, 113 seconds between -25 and -14C, 1200 seconds in any case above -25C).
You need to check your water inlet with thermostat, make sure the thermostat opens at 176-183F and closes fully when below 176F. Otherwise the water inlet with thermostat needs replacement, part # 16031-0S010, ~$48. Also be sure to bleed air out of the coolant system. Ensure the radiator fans don't turn on before the system is up to temperature. Also, it is easy to replace the engine coolant temperature sensor, should be part # 89422-33030, ~$66. There should also be a metal gasket, I don't have the part # on hand though. It is also easy to replace your MAF sensor, part 22204-38020, ~$216.
The diagram of your cooling system can be found at https://jimhudsonaugustaparts.com/pa...agramCallOut=4
Worst case, the ECM is faulty, 89661-50F90 $1100.
P0300 (Random / Multiple Cylinder Misfire): Simultaneous misfiring of several cylinders detected. Trouble areas: open/short in engine wire harness, vacuum hose connections, ignition system, injectors, fuel pressure, MAF, engine coolant temperature sensor, compression, valve clearance/timing, ventiliation hoses/valve, air intake system, ECM/ECU.
To troubleshoot this properly, look at the freeze-frame data, you may need Techstream to do this. When the misfire happens, the computer will store freeze-frame data, showing what every sensor is reading at that exact moment. The important things to look at are coolant temp, misfire rpm, misfire load, Short Term Fuel Trim, Long Term Fuel Trim (neither will be accurate if you recently reset the codes), fuel pump duty, STFT1+LTFT1, STFT2+LTFT2. Check all your ventilation hose connections. There are further tests you can do in Techstream to test the misfiring of port injection and direct injection. Your low-side fuel pressure rail should measure 196-588 kPa (28-85 psi). Fuel pressure sensor reading in Techstream should be 2000-5000kPa at idle, with A/C and all accessories off and engine fully warmed up. Fuel pressure pulsation damper could be faulty, 23270-38010 ~$110, or fuel pressure regulator 23280-38020 ~$155, or fuel pressure sensor 90980-11451. I think it's unlikely that it's the O2 sensor.
P0125 (Insufficient Coolant Temp for Closed Loop Fuel Control): Related to DTC P0115. Resistance of ECT (Engine Coolant Temp) sensor varies in proportion to actual ECT. After engine is started, ECT is monitored through ECT sensor. If ECT sensor indicated engine isn't warm enough for closed-loop fuel control, despite a specified period of time having elapsed since engine start, ECM interprets this as malfunction in ECT sensor or cooling system. The specified period of time depends on the starting engine coolant temperature (60 seconds at -14C or above, 113 seconds between -25 and -14C, 1200 seconds in any case above -25C).
You need to check your water inlet with thermostat, make sure the thermostat opens at 176-183F and closes fully when below 176F. Otherwise the water inlet with thermostat needs replacement, part # 16031-0S010, ~$48. Also be sure to bleed air out of the coolant system. Ensure the radiator fans don't turn on before the system is up to temperature. Also, it is easy to replace the engine coolant temperature sensor, should be part # 89422-33030, ~$66. There should also be a metal gasket, I don't have the part # on hand though. It is also easy to replace your MAF sensor, part 22204-38020, ~$216.
The diagram of your cooling system can be found at https://jimhudsonaugustaparts.com/pa...agramCallOut=4
Worst case, the ECM is faulty, 89661-50F90 $1100.
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FrankT (06-15-19)
11-14-22, 04:56 PM
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Where is my ect sensor located in my ls460 ?
Where is t
this code is not showing up as a check engine light. It is only showing up under the enhanced scan with my scan tool under “Readyness test”
i noticed I have a lot of excessive exhaust from the tail pipes than all the other cars this time of year even after letting warm up. It only went away for a few min. After driving on 90 and parked but came back again after it sat and idled for about 10 min.
code says the temp is not getting hot enough to close fuel loop so I think I’m getting extra fuel vapor.
Had it at the dealer yesterday for a complete inspection for first time since I just purchased 2 days ago and they never pulled or said anything about that code.
I found it could be Low on Coolant (nope) - bad or dirty sensor- bad connection- stuck open thermostat or bad Ecm... (I don’t think it’s the latter)
i did have an air pocket in the radiator as I could hear water gargling in the glove box. The dealer put an air remover on during the inspection so that’s done. But code is still there...
can someone tell me has this happened to you?
Where is the Thermostat Located?
Where is the Ect Sensor located?
(Diagrams work best for me)
getting terrible fuel fuel economy and I am sure it’s because of this,
LS460 2010
i noticed I have a lot of excessive exhaust from the tail pipes than all the other cars this time of year even after letting warm up. It only went away for a few min. After driving on 90 and parked but came back again after it sat and idled for about 10 min.
code says the temp is not getting hot enough to close fuel loop so I think I’m getting extra fuel vapor.
Had it at the dealer yesterday for a complete inspection for first time since I just purchased 2 days ago and they never pulled or said anything about that code.
I found it could be Low on Coolant (nope) - bad or dirty sensor- bad connection- stuck open thermostat or bad Ecm... (I don’t think it’s the latter)
i did have an air pocket in the radiator as I could hear water gargling in the glove box. The dealer put an air remover on during the inspection so that’s done. But code is still there...
can someone tell me has this happened to you?
Where is the Thermostat Located?
Where is the Ect Sensor located?
(Diagrams work best for me)
getting terrible fuel fuel economy and I am sure it’s because of this,
LS460 2010
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