Question on DTC

[Dogsofjune]

The truck threw two codes last week. P0106, P0128.

I Googled to discover that P0106, hopefully correctly, that it's related to "MAP system performance"? That right?

The P0128 is due to a 180* t-stat and the exceptionally cool weather we've been having lately.

It kicked up when I was on a long drive. Not sure what to look for for a fix. I don't suppose the two are related?

MAP? Manifold Absolute Pressure?
I've been running the 2114 MPFI setup since October and under boost since mid to late November. No problems prior to this. I wonder what's up.

[fastSdime]

**** Dan that sucks.. I will do some reserch on this for you tho..

[Sparky2263]

The P0106 is a performance code for the MAP sensor. The expected values are not met (nor will they be, because of the supercharger). It is a very hard code to set because the conditions are so stringent (see below). It will only happen on a long drive or a big change in altitude on a single key cycle. Clear it and don't sweat it.

The P0128, I would get a NAPA Super-stat to solve that issue. Ck. my recent post on that issue.

CIRCUIT DESCRIPTION
The manifold absolute pressure (MAP) sensor (http://www.motoralldata.com/alldata/MOTOR~V28474354~C37456~R0~OD~N/0/89012112/94695002/94695157/94695159/34853741/34857029/34857030/34857526) responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:



5-volt reference circuit
Low reference circuit
MAP sensor signal circuit
The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP (http://www.motoralldata.com/alldata/MOTOR~V28474354~C37456~R0~OD~N/0/89012112/94695002/94695157/94695159/34853741/34857029/34857030/34857526), such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used in order to determine the barometric pressure (BARO). This occurs when the ignition switch (http://www.motoralldata.com/alldata/MOTOR~V28474354~C37456~R0~OD~N/0/89012112/94695002/94695157/94695159/34853741/34857029/34859584/101367270) is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.

The PCM calculates a predicted value for the MAP sensor based on the throttle position (TP) and the engine speed. The PCM then compares the predicted value to the actual MAP sensor signal. If the PCM detects that the MAP sensor signal is not within the predicted range, DTC P0106 sets.

CONDITIONS FOR RUNNING THE DTC



DTCs P0101, P0102, P0103, P0107, P0108, P0121, P0122, P0123, P0442, P0443, P0446 are not set.
The engine is running.
The engine speed is between 400-5,000 RPM .
Any change in the engine speed is less than 125 RPM .
The traction control is not active.
Any change in the idle air is less than 10 g/s .
The A/C compressor clutch state does not change.
The power steering load is stable.
The brake switch state does not change.
The above conditions are met for 1 second .
CONDITIONS FOR SETTING THE DTC
The PCM detects that the actual MAP sensor signal is not within the predicted range for 1.5 seconds .

[Dogsofjune]

Excellent, thanks for the response.

I cleared it and will look at the NAPA super-stat.

[Dogsofjune]

Ok, revisiting this issue. P0128 is exactly what on an '03?

T-Stat issue or faulty O2 sensor (bank 1)?

Getting mixed opinions on this. MPG has changed, not horrible, but that could be due to cool weather, addition of S/C, not keeping my foot out of it due to S/C.

Google searches on DTC's has provided inconsistant results.

[Sparky2263]

Computer expects to see 178 degs coolant temp within a certain time frame from a cold start. If it doesn't, it sets a code P0128.

Has nothing to do with the O2 sensor.

[Dogsofjune]

I understand that.

The reason for the question was due to picking the truck up from the shop, after a comp tune and new injectors, they stated that according to the info they had, P0128 was O2 problem, not a t-stat issue.

I'm lookin' for absolute clarification, before proceding on a solution.

[Sparky2263]

CIRCUIT DESCRIPTION
The engine coolant temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the powertrain control module (PCM) for engine control, and as an enabling criteria for some diagnostics.

The air flow coming into the engine is accumulated and used to determine if the vehicle has been driven within the conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not increase normally or does not reach the regulating temperature of the thermostat, diagnostics that use ECT as enabling criteria, may not run when expected.

This DTC will only run once per ignition cycle within the enabling condition. If the PCM detects the calibrated amount of air flow and engine run time have been met and the ECT has not met the minimum thermostat regulating temperature, DTC P0128 sets.

CONDITIONS FOR RUNNING THE DTC



DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0125, P0500, P0502, P0503 are not set.
The start-up engine coolant temperature is less than 76°C (169°F).
The intake air temperature (IAT) is between -7 and +55°C (19-131°F).
The engine has been running between 120-2,100 seconds.
The vehicle speed is more than 8 km/h (5 mph) for more than 2.5 km (1.5 miles).
The mass air flow (MAF) is between 15-75 g/s , with the average more than 12 g/s.
CONDITIONS FOR SETTING THE DTC
The PCM detects that:



The calibrated amount of engine run time has been met.
The calibrated amount of engine air flow has been met.
The calibrated minimum engine coolant temperature of 81°C (178°F) has not been met.
ACTION TAKEN WHEN THE DTC SETS



The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC



The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.

(Courtesy General Motors)

[Dogsofjune]

I was pretty confident that is was indeed a t-stat issue.
I appreciate the clarification. Now it's time for a run to NAPA.

[Dogsofjune]

Threw the P0106 again almost a year later, lol. Only seems to happen when I go out of town to visit towns an hour+ drive away:

Salina KS. Elevation: 1225 feet
Garnett KS. Elevation: 1,063 feet
Manhattan KS. Elevation: 1020 feet

Lawrence KS. Elevation: 850 feet.
Man I need my HPTuner software delivered and get the 2bar set up.