DTC P2071

DTC P2071: Intake Manifold Tuning (IMT) Valve Stuck in Low RPM Position

General Description

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

The intake manifold tuning (IMT) system aids engine output by selecting either long or short intake runner lengths. The system consists of the IMT valve, the IMT actuator, and the powertrain control module (PCM). The IMT actuator is attached to the intake manifold and it includes the motor and the Hall-effect-IC position sensing unit. The PCM actuates the motor, which operates the IMT valve. When the IMT valve is closed, the long runner is selected, increasing torque at low engine speed. When the IMT valve is open, the short runner is selected, increasing torque at high engine speed. A Hall-effect-IC position sensing unit is integrated with the motor to provide precise open/close feedback to the PCM. The IMT actuator sends a long runner return signal to the PCM when the IMT valve is closed, and it sends a short runner return signal when the IMT valve is open. If the PCM receives no closed return signal when it sends a close command, or if it receives no open return signal when sending an open command to the IMT actuator, for a specified time, it detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status

Execution	Once per driving cycle
Sequence	None
Duration	3.0 seconds or more
DTC Type*1	Two drive cycles, MIL on
DTC Type*2	Two drive cycles, MIL off
OBD Status	PASSED/FAILED/NOT COMPLETED (STILL TESTING)

*1: USA and Canada models

*2: Mexico models

Enable Conditions

Condition	Minimum	Maximum
Engine speed [ENGINE SPEED]	3, 900 RPM	-
No active DTCs set (prevents monitor from running)	P0112, P0113
Other	Not when the engine is stopped

[ ]: HDS Parameter

Malfunction Threshold

When the PCM sends an open (short runner) command, no short runner return signal is received for at least 3.0 seconds.

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes

Motor poor operation
Gear lock
Gear slip
Shaft lock
Shaft interference
IMT valve stuck
IMT actuator SVSP line open
IMT actuator SVSP line short to ground
IMT actuator SVSM line open
IMT actuator SVSM line short to ground
IMT actuator SVM line short to ground

Confirmation Procedure

With the HDS

Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS.

With the Driving Pattern

Start the engine. Hold the engine speed [ENGINE SPEED] at 3, 000 RPM without load (in P or N) until the radiator fan comes on.
Hold the engine speed [ENGINE SPEED] at 3, 900 RPM or more for at least 3.0 seconds.

Diagnosis Details*1

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

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, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.

Diagnosis Details*2

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC and the freeze data are stored. The MIL does not come on.

Conditions for clearing the DTC

The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.