DTC Advanced Diagnostics: P2176 (2.0L Engine) (2024 2025)

DTC P2176  : Throttle Actuator Control System Idle Position Not Learned

General Description 

Courtesy of HONDA, U.S.A., INC.

The electronic throttle control system starts a learning routine of throttle valve position to correlate the measured value of the throttle position (TP) sensors to the mechanical throttle valve position. The electronic throttle control system uses default values for the lower mechanical stop initially, and then it learns the actual value each time the throttle body is used. During the learning routine, the throttle valve steps from the maximum possible value of the lower mechanical stop to the measured value at the actual lower mechanical stop position. If the throttle body lower mechanical limit cannot be learned, the powertrain control module (PCM) detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type 

Execution	Once per driving cycle
Sequence	None
Duration	0.5 seconds or more
DTC Type	One drive cycle, MIL on

Enable Conditions 

Condition	Minimum	Maximum
Elapsed time after the vehicle is turned to the OFF (LOCK) mode	5 seconds	-
Engine coolant temperature [ECT Sensor 1]	41.5 deg.F (5.26 deg.C)	212.8 deg.F (100.46 deg.C)
Intake air temperature [IAT Sensor (1)]	41.5 deg.F (5.26 deg.C)	289.8 deg.F (143.26 deg.C)
Engine speed [Engine Speed]	-	250 rpm
Vehicle speed [Vehicle Speed]	-	0.6 mph (1 km/h)
12 volt battery voltage [Battery]	10.5 V	16.5 V

[ ]: HDS Parameter

Malfunction Threshold 

• Initial learning of the closed throttle valve position not possible

  The initial learning is not performed.

• Learning of the closed throttle valve position not possible

  Either of the condition occurs:

• • -

    The difference between the actual learned TP sensor A voltage and the previous read TP sensor A voltage at the mechanical stop is -0.07 V or more.

  • -

    The difference between the actual learned TP sensor B voltage and the previous read TP sensor A voltage at the mechanical stop is -0.07 V or more.

• Closed throttle valve position exceeds the threshold

  Either of the condition occurs:

• • -

    The TP sensor A voltage is more than 0.69 V or less than 0.51 V during sensor offset learning at lower mechanical stop.

  • -

    The TP sensor B voltage is more than 4.49 V or less than 4.31 V during sensor offset learning at lower mechanical stop.

Possible Cause 

Confirmation Procedure 

Operating Condition 

• Turn the vehicle to the OFF (LOCK) mode.
• Turn the vehicle to the ON mode.

Diagnosis Details 

Conditions for setting the DTC 

When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.

Conditions for clearing the DTC 

The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.