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97 Explorer 5.0 with P0125 Code
97 Explorer 5.0 with P0125 Code
This shows a generic code for "Insufficient Coolant Temperature for
Closed Loop Fuel Control". Does anyone have an idea which sensor
would cause this code? Is it the engine temperature sensor C159 on
the radiator? Maybe the engine coolant temperature sensor on the
engine C163? Could this be a computer problem? Any help would be
appreciated, I have been chasing this for a couple months. I reset
the CEL and it's fine for a week or two then it comes back.
This shows a generic code for "Insufficient Coolant Temperature for
Closed Loop Fuel Control". Does anyone have an idea which sensor
would cause this code? Is it the engine temperature sensor C159 on
the radiator? Maybe the engine coolant temperature sensor on the
engine C163? Could this be a computer problem? Any help would be
appreciated, I have been chasing this for a couple months. I reset
the CEL and it's fine for a week or two then it comes back.
Re: 97 Explorer 5.0 with P0125 Code
Is the engine coming up to operating temp? Perhaps it needs a new
thermostat...
"kc10" <kc10@kc10,net > wrote in message
news:bq1bo2tl3ierhre7l2cvf7mj6gut6mqou7@4ax,com ...
> This shows a generic code for "Insufficient Coolant Temperature for
> Closed Loop Fuel Control". Does anyone have an idea which sensor
> would cause this code? Is it the engine temperature sensor C159 on
> the radiator? Maybe the engine coolant temperature sensor on the
> engine C163? Could this be a computer problem? Any help would be
> appreciated, I have been chasing this for a couple months. I reset
> the CEL and it's fine for a week or two then it comes back.
Is the engine coming up to operating temp? Perhaps it needs a new
thermostat...
"kc10" <kc10@kc10,net > wrote in message
news:bq1bo2tl3ierhre7l2cvf7mj6gut6mqou7@4ax,com ...
> This shows a generic code for "Insufficient Coolant Temperature for
> Closed Loop Fuel Control". Does anyone have an idea which sensor
> would cause this code? Is it the engine temperature sensor C159 on
> the radiator? Maybe the engine coolant temperature sensor on the
> engine C163? Could this be a computer problem? Any help would be
> appreciated, I have been chasing this for a couple months. I reset
> the CEL and it's fine for a week or two then it comes back.
Re: 97 Explorer 5.0 with P0125 Code
The engine seems to be warming to a normal operating temperature
On Sun, 17 Dec 2006 19:29:22 GMT, "Jim Warman"
<mechanic@telusplanet,net > wrote:
>Is the engine coming up to operating temp? Perhaps it needs a new
>thermostat...
>
>
>"kc10" <kc10@kc10,net > wrote in message
>news:bq1bo2tl3ierhre7l2cvf7mj6gut6mqou7@4ax,com ...
>> This shows a generic code for "Insufficient Coolant Temperature for
>> Closed Loop Fuel Control". Does anyone have an idea which sensor
>> would cause this code? Is it the engine temperature sensor C159 on
>> the radiator? Maybe the engine coolant temperature sensor on the
>> engine C163? Could this be a computer problem? Any help would be
>> appreciated, I have been chasing this for a couple months. I reset
>> the CEL and it's fine for a week or two then it comes back.
>
The engine seems to be warming to a normal operating temperature
On Sun, 17 Dec 2006 19:29:22 GMT, "Jim Warman"
<mechanic@telusplanet,net > wrote:
>Is the engine coming up to operating temp? Perhaps it needs a new
>thermostat...
>
>
>"kc10" <kc10@kc10,net > wrote in message
>news:bq1bo2tl3ierhre7l2cvf7mj6gut6mqou7@4ax,com ...
>> This shows a generic code for "Insufficient Coolant Temperature for
>> Closed Loop Fuel Control". Does anyone have an idea which sensor
>> would cause this code? Is it the engine temperature sensor C159 on
>> the radiator? Maybe the engine coolant temperature sensor on the
>> engine C163? Could this be a computer problem? Any help would be
>> appreciated, I have been chasing this for a couple months. I reset
>> the CEL and it's fine for a week or two then it comes back.
>
Re: 97 Explorer 5.0 with P0125 Code
To be honest, you really need to be a little more sure than "seems"....
While it is possible that the ECT is faulty, it is rare that these sensors
require replacement. These sensors are a simple thermistor and there's not
much that can go wrong with them.
To be honest, you really need to be a little more sure than "seems"....
While it is possible that the ECT is faulty, it is rare that these sensors
require replacement. These sensors are a simple thermistor and there's not
much that can go wrong with them.
Re: 97 Explorer 5.0 with P0125 Code
I'll probably replace it just to be sure that it is not the problem .
The needle on the instrument panel shows middle of the gauge. The
radiator shows 200 F on a IR thermometer. Could it be a bad ground or
a broken wire to one of the sensors?
On Mon, 18 Dec 2006 01:32:40 GMT, "Jim Warman"
<mechanic@telusplanet,net > wrote:
>To be honest, you really need to be a little more sure than "seems"....
>While it is possible that the ECT is faulty, it is rare that these sensors
>require replacement. These sensors are a simple thermistor and there's not
>much that can go wrong with them.
>
I'll probably replace it just to be sure that it is not the problem .
The needle on the instrument panel shows middle of the gauge. The
radiator shows 200 F on a IR thermometer. Could it be a bad ground or
a broken wire to one of the sensors?
On Mon, 18 Dec 2006 01:32:40 GMT, "Jim Warman"
<mechanic@telusplanet,net > wrote:
>To be honest, you really need to be a little more sure than "seems"....
>While it is possible that the ECT is faulty, it is rare that these sensors
>require replacement. These sensors are a simple thermistor and there's not
>much that can go wrong with them.
>
Re: 97 Explorer 5.0 with P0125 Code
OK.... info is our friend... The ECT and the (IIRC) IAT both share the same
line for VREF.... about 4.5 or 5 volts. Since these thermistors react
inversely, cooler = higher resistance..... If your IR thermometer shows
200F when you point it at the thermostat housing, you can unplug the ECT and
measure the resistance across the two pins.... Expect in the neighbourhood
of 2.5K ohms - give or take. If this is good, suspect corroded or spead
terminals in the wiring connectors.... <aybe wiring concerns if someone has
been in there poking and prodding... I would expect there to be (at least)
three connectors in the circuit.... one at the PCM, one at the sensor and
another where the engine harness and the chassis harness meet.
You couls also use your DMM to back probe the sensor terminals while the
connector is connected and the engine is running. Measure between the VREF
terminal and the battery ground should give the 4.5 to 5 volt indication....
sig return will depend on engine temp.... operating range is about 0.3 volt
to about 3.5 volt - at 200ish degrees, expect something around a half
volt....
FWIW, this type of circuit is a "voltage divider" type circuit... If you are
unfamiliar (this is not intended as an insult), you can Google the term and
should find some pretty good explanations of the concept...
OK.... info is our friend... The ECT and the (IIRC) IAT both share the same
line for VREF.... about 4.5 or 5 volts. Since these thermistors react
inversely, cooler = higher resistance..... If your IR thermometer shows
200F when you point it at the thermostat housing, you can unplug the ECT and
measure the resistance across the two pins.... Expect in the neighbourhood
of 2.5K ohms - give or take. If this is good, suspect corroded or spead
terminals in the wiring connectors.... <aybe wiring concerns if someone has
been in there poking and prodding... I would expect there to be (at least)
three connectors in the circuit.... one at the PCM, one at the sensor and
another where the engine harness and the chassis harness meet.
You couls also use your DMM to back probe the sensor terminals while the
connector is connected and the engine is running. Measure between the VREF
terminal and the battery ground should give the 4.5 to 5 volt indication....
sig return will depend on engine temp.... operating range is about 0.3 volt
to about 3.5 volt - at 200ish degrees, expect something around a half
volt....
FWIW, this type of circuit is a "voltage divider" type circuit... If you are
unfamiliar (this is not intended as an insult), you can Google the term and
should find some pretty good explanations of the concept...
Re: 97 Explorer 5.0 with P0125 Code
Thanks...you have given me something to work with. I will have to
Google the "voltage divider as I am not familar. I'll let you know
what turns out to be the problem.
On Mon, 18 Dec 2006 08:18:44 GMT, "Jim Warman"
<mechanic@telusplanet,net > wrote:
>OK.... info is our friend... The ECT and the (IIRC) IAT both share the same
>line for VREF.... about 4.5 or 5 volts. Since these thermistors react
>inversely, cooler = higher resistance..... If your IR thermometer shows
>200F when you point it at the thermostat housing, you can unplug the ECT and
>measure the resistance across the two pins.... Expect in the neighbourhood
>of 2.5K ohms - give or take. If this is good, suspect corroded or spead
>terminals in the wiring connectors.... <aybe wiring concerns if someone has
>been in there poking and prodding... I would expect there to be (at least)
>three connectors in the circuit.... one at the PCM, one at the sensor and
>another where the engine harness and the chassis harness meet.
>
>You couls also use your DMM to back probe the sensor terminals while the
>connector is connected and the engine is running. Measure between the VREF
>terminal and the battery ground should give the 4.5 to 5 volt indication....
>sig return will depend on engine temp.... operating range is about 0.3 volt
>to about 3.5 volt - at 200ish degrees, expect something around a half
>volt....
>
>FWIW, this type of circuit is a "voltage divider" type circuit... If you are
>unfamiliar (this is not intended as an insult), you can Google the term and
>should find some pretty good explanations of the concept...
>
>
Thanks...you have given me something to work with. I will have to
Google the "voltage divider as I am not familar. I'll let you know
what turns out to be the problem.
On Mon, 18 Dec 2006 08:18:44 GMT, "Jim Warman"
<mechanic@telusplanet,net > wrote:
>OK.... info is our friend... The ECT and the (IIRC) IAT both share the same
>line for VREF.... about 4.5 or 5 volts. Since these thermistors react
>inversely, cooler = higher resistance..... If your IR thermometer shows
>200F when you point it at the thermostat housing, you can unplug the ECT and
>measure the resistance across the two pins.... Expect in the neighbourhood
>of 2.5K ohms - give or take. If this is good, suspect corroded or spead
>terminals in the wiring connectors.... <aybe wiring concerns if someone has
>been in there poking and prodding... I would expect there to be (at least)
>three connectors in the circuit.... one at the PCM, one at the sensor and
>another where the engine harness and the chassis harness meet.
>
>You couls also use your DMM to back probe the sensor terminals while the
>connector is connected and the engine is running. Measure between the VREF
>terminal and the battery ground should give the 4.5 to 5 volt indication....
>sig return will depend on engine temp.... operating range is about 0.3 volt
>to about 3.5 volt - at 200ish degrees, expect something around a half
>volt....
>
>FWIW, this type of circuit is a "voltage divider" type circuit... If you are
>unfamiliar (this is not intended as an insult), you can Google the term and
>should find some pretty good explanations of the concept...
>
>
Re: 97 Explorer 5.0 with P0125 Code
Jim...your original diagnosis of the bad themostat was correct. When
I got it out, it would not close completely and didn't allowed the
antifreeze to warmup. I live in Phoenix and until a couple weeks ago
we had warm weather, so the stuck themostat wasn't apparent. Great
Job!
On Mon, 18 Dec 2006 18:17:33 -0700, kc10 <kc10@kc10,net > wrote:
>Thanks...you have given me something to work with. I will have to
>Google the "voltage divider as I am not familar. I'll let you know
>what turns out to be the problem.
>
>On Mon, 18 Dec 2006 08:18:44 GMT, "Jim Warman"
><mechanic@telusplanet,net > wrote:
>
>>OK.... info is our friend... The ECT and the (IIRC) IAT both share the same
>>line for VREF.... about 4.5 or 5 volts. Since these thermistors react
>>inversely, cooler = higher resistance..... If your IR thermometer shows
>>200F when you point it at the thermostat housing, you can unplug the ECT and
>>measure the resistance across the two pins.... Expect in the neighbourhood
>>of 2.5K ohms - give or take. If this is good, suspect corroded or spead
>>terminals in the wiring connectors.... <aybe wiring concerns if someone has
>>been in there poking and prodding... I would expect there to be (at least)
>>three connectors in the circuit.... one at the PCM, one at the sensor and
>>another where the engine harness and the chassis harness meet.
>>
>>You couls also use your DMM to back probe the sensor terminals while the
>>connector is connected and the engine is running. Measure between the VREF
>>terminal and the battery ground should give the 4.5 to 5 volt indication....
>>sig return will depend on engine temp.... operating range is about 0.3 volt
>>to about 3.5 volt - at 200ish degrees, expect something around a half
>>volt....
>>
>>FWIW, this type of circuit is a "voltage divider" type circuit... If you are
>>unfamiliar (this is not intended as an insult), you can Google the term and
>>should find some pretty good explanations of the concept...
>>
>>
Jim...your original diagnosis of the bad themostat was correct. When
I got it out, it would not close completely and didn't allowed the
antifreeze to warmup. I live in Phoenix and until a couple weeks ago
we had warm weather, so the stuck themostat wasn't apparent. Great
Job!
On Mon, 18 Dec 2006 18:17:33 -0700, kc10 <kc10@kc10,net > wrote:
>Thanks...you have given me something to work with. I will have to
>Google the "voltage divider as I am not familar. I'll let you know
>what turns out to be the problem.
>
>On Mon, 18 Dec 2006 08:18:44 GMT, "Jim Warman"
><mechanic@telusplanet,net > wrote:
>
>>OK.... info is our friend... The ECT and the (IIRC) IAT both share the same
>>line for VREF.... about 4.5 or 5 volts. Since these thermistors react
>>inversely, cooler = higher resistance..... If your IR thermometer shows
>>200F when you point it at the thermostat housing, you can unplug the ECT and
>>measure the resistance across the two pins.... Expect in the neighbourhood
>>of 2.5K ohms - give or take. If this is good, suspect corroded or spead
>>terminals in the wiring connectors.... <aybe wiring concerns if someone has
>>been in there poking and prodding... I would expect there to be (at least)
>>three connectors in the circuit.... one at the PCM, one at the sensor and
>>another where the engine harness and the chassis harness meet.
>>
>>You couls also use your DMM to back probe the sensor terminals while the
>>connector is connected and the engine is running. Measure between the VREF
>>terminal and the battery ground should give the 4.5 to 5 volt indication....
>>sig return will depend on engine temp.... operating range is about 0.3 volt
>>to about 3.5 volt - at 200ish degrees, expect something around a half
>>volt....
>>
>>FWIW, this type of circuit is a "voltage divider" type circuit... If you are
>>unfamiliar (this is not intended as an insult), you can Google the term and
>>should find some pretty good explanations of the concept...
>>
>>
