'01 Buick Le Sabre SES Light On

OBD2 (from AZ) 1.)Low Coolant, 2.)Thermostat defective, 3.)ECT defective Coolant is up to proper level-could there be an air gap at the ECT?
Temp gauge and heat are working.
If there is no air gap at the ECT, that would seem to be bad.
85K,2nd owner-with moderate knowledge.

Anything to add would be appreciated!

Bob Villa > wrote in
:

> OBD2 (from AZ) 1.)Low Coolant, 2.)Thermostat defective, 3.)ECT
> defective



Please give the actual alphanumeric codes, not the text descriptions.

Codes are a letter followed by four numbers (sometimes also letters as
well). Example: P0301.



--
Tegger

On Wednesday, February 26, 2014 9:18:04 AM UTC-6, Tegger wrote:

> Please give the actual alphanumeric codes, not the text descriptions.

> Codes are a letter followed by four numbers (sometimes also letters as
>
> well). Example: P0301.

P0128

Bob Villa > wrote in news:3e19fda0-bf91-410a-9c6c-
:

> On Wednesday, February 26, 2014 9:18:04 AM UTC-6, Tegger wrote:
>
>> Please give the actual alphanumeric codes, not the text descriptions.
>
>> Codes are a letter followed by four numbers (sometimes also letters as
>>
>> well). Example: P0301.
>
> P0128


You gave three errors originally, but only one code now. How come?

--
Tegger

On Wednesday, February 26, 2014 10:19:08 AM UTC-6, Tegger wrote:
> Bob Villa > wrote in news:3e19fda0-bf91-410a-9c6c-
>
> :
>
>
>
> > On Wednesday, February 26, 2014 9:18:04 AM UTC-6, Tegger wrote:
>
> >
>
> >> Please give the actual alphanumeric codes, not the text descriptions.
>
> >
>
> >> Codes are a letter followed by four numbers (sometimes also letters as
>
> >>
>
> >> well). Example: P0301.
>
> >
>
> > P0128
>
>
>
>
>
> You gave three errors originally, but only one code now. How come?
>
>
>
> --
>
> Tegger

That's all the print-out gives...and then the possibilities of fault.

On 2/26/2014 6:53 AM, Bob Villa wrote:
>
> That's all the print-out gives...and then the possibilities of fault.
>

Thanks to the OBD II, you should be able to solve this problem in 20
minutes or so. :-)

OTOH, are you having any other symptom than the service engine light
being on? If there isn't, I'd reset the light and see if it gets another
error code gets trapped. Sometimes the don't come back.

On Wednesday, February 26, 2014 11:18:34 AM UTC-6, dsi1 wrote:
> On 2/26/2014 6:53 AM, Bob Villa wrote:
>
> >
>
> > That's all the print-out gives...and then the possibilities of fault.
>
> >
>
>
>
> Thanks to the OBD II, you should be able to solve this problem in 20
>
> minutes or so. :-)
>
>
>
> OTOH, are you having any other symptom than the service engine light
>
> being on? If there isn't, I'd reset the light and see if it gets another
>
> error code gets trapped. Sometimes the don't come back.

After taking a trip the MPG is 20% or so worse...and I would need the scanner to reset the fault.
I think I will change the stat ($8.50) and then the sensor ($18.50) if needed.

dsi1 > wrote:
>On 2/26/2014 6:53 AM, Bob Villa wrote:
>>
>> That's all the print-out gives...and then the possibilities of fault.
>
>Thanks to the OBD II, you should be able to solve this problem in 20
>minutes or so. :-)

P0128 means the computer has noticed that the engine is not coming up to
temperature quickly enough.

So, your first question is: is the engine coming up to temperature properly?
If it seems to be (do you have a temperature gauge on the dash?) then check
the temperature sensor that tells the computer what the engine temperature
is. Otherwise swap the thermostat.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

dsi1 wrote:
> On 2/26/2014 6:53 AM, Bob Villa wrote:
>> That's all the print-out gives...and then the possibilities of fault.
>>
>
> Thanks to the OBD II, you should be able to solve this problem in 20
> minutes or so. :-)
>
> OTOH, are you having any other symptom than the service engine light
> being on? If there isn't, I'd reset the light and see if it gets another
> error code gets trapped. Sometimes the don't come back.


Maybe if you learned about real diagnostics using a good scan tool you
would have repaired the problem in less than 30 minutes.

Customers initial complaint -
Check engine light on and decreased fuel mileage. (probably low heat as
well but may have not noticed)

Put scan tool plug into the port turn on key and run a scan.

Code says -
P0128 = Engine not coming up to full operating temp.
No other codes (at least none that the code reader they used show)

Possible causes (as any P0XXX is a generic OBDII code)

Low coolant
Bad thermostat
Bad ECT
Cooling fan relay failure (fans on constantly)

From inside the car -

Pull the freeze frame data and it shows the engine had been running for
138 minutes, at 2,100 rpm, at 53 mph and engine load of 12% with a
coolant temp of 161 degrees when the code was set (there will be more
data but that coolant temp vs run time and load are the ones you need to
see for this code.) Normal coolant temp under those conditions would be
210-220 degrees. Yep it's running cold. WHY?


A bad ECT will set one or more of the following codes -

P1114 - ECT Sensor Circuit Intermittent Low Voltage (sensor/wiring
shorting to ground)

P1115 - ECT Sensor Circuit Intermittent High Voltage (sensor/wiring
shorting to 5 volt reference)

P1116 - ECT Signal Unstable Or Intermittent (sensor/wiring faulty)

P1117 - ECT Signal Out-Of-Range Low (Thermistor failing with increased
resistance)

P1118 - Engine Coolant Temp Signal Out-Of Range High (Thermistor
failing with decreased resistance)

P1119 - ECT Signal Out Of Range With TFT Sensor

These are all available on a good scan tool and point directly to the
problem. Either the wiring or the sensor unless they used a cheap code
reader only and not a scan tool capable of OEM specific codes and didn't
get ALL the codes.

Go into bi directional control and cycle the cooling fans. They cycle
on/off OK

So it isn't the fans or ECT sensor causing the code.

Open hood. Smell for excess gas, pull dipstick to make sure no gas or
water in oil. None noted. (Why, because another possible reason for
poor mileage and a cool running engine could be a leaking injector
causing a rich mix. Usually this would also set a code but it never
hurts to check. Water check because a leaking intake or head gasket
could be dumping water into the engine causing a low coolant condition.)

Nothing found. Check coolant level in overflow - OK,
Check actual coolant level in radiator - OK

Most likely fault - Bad Thermostat - Failed fully open.


Notify customer - outline possibilities for repair.

Drain coolant - replace thermostat - refill

Coolant flush (if system shows signs of low maintenance and low coolant
concentration) - new thermostat and refill.


--
Steve W.

On Wednesday, February 26, 2014 2:52:32 PM UTC-6, Steve W. wrote:

>
> Maybe if you learned about real diagnostics using a good scan tool you
>
> would have repaired the problem in less than 30 minutes.
>

Steve, thanks for being so understanding (as always)...you will note in the original post "85K,2nd owner-with moderate knowledge"!