DTC P2176: Throttle Actuator Control System Idle Position Not Learned

CAUTION: Do not insert your fingers into the installed throttle body when you turn the ignition switch to ON (II) or while the ignition switch is in ON (II). If you do, you will seriously injure your fingers if the throttle valve is activated.

NOTE:

Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
If DTC P2135 is stored at the same time as DTC P2176, troubleshoot DTC P2135 first, then recheck for DTC P2176.

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and wait 10 seconds.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P2176 indicated?

YES -Go to step 6.

NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body and the ECM/PCM, then clean the throttle body (see THROTTLE BODY CLEANING ).
Turn the ignition switch to LOCK (0).
Remove the air cleaner from the throttle body (see AIR CLEANER ELEMENT INSPECTION/REPLACEMENT ).
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Visually check the throttle valve operation while doing the ETCS TEST in the INSPECTION MENU with the HDS.
Does the throttle valve move to its fully closed position?

YES -Go to step 11.

NO -Go to step 12.
Check for sludge or carbon on the throttle valve.
Is there sludge or carbon on the throttle valve?

YES -Clean the throttle body (see THROTTLE BODY CLEANING ), then go to step 21.

NO -Go to step 18.
Turn the ignition switch to LOCK (0).
Disconnect the throttle body 6P connector.
Jump the SCS line with the HDS.
Disconnect ECM/PCM connector C (44P).
Connect throttle body 6P connector terminals No. 1 and No. 2 with a jumper wire.

Fig 1: Connecting Throttle Body 6P Connector Terminals No. 1 And No. 2 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between ECM/PCM connector terminals C3 and C4.

Fig 2: Checking Continuity Between ECM/PCM Connector Terminals C3 And C4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 27.

NO -Repair an open in the wires between the ECM/PCM (C3, C4) and the throttle body, then go to step 20.
Turn the ignition switch to LOCK (0).
Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the ECM/PCM with the HDS.
Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and wait 10 seconds.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P2176 indicated?

YES -Check for poor connections or loose terminals at the throttle body and the ECM/PCM, then clean the throttle body (see THROTTLE BODY CLEANING ), and go to step 1.

NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC'S TROUBLESHOOTING .
Reconnect all connectors.
Update the ECM/PCM if it does not have the latest software (see ELD REPLACEMENT ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
Turn the ignition switch to LOCK (0).
Turn the ignition switch to ON (II), and wait 10 seconds.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P2176 indicated?

YES -Check for poor connections or loose terminals at the throttle body and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the ECM/PCM was substituted, go to step 1.

NO -If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ). If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC'S TROUBLESHOOTING .