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 PCM, then clean the throttle body (see THROTTLE BODY TEST ).
Turn the ignition switch to LOCK (0).
Disconnect the intake air duct from the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
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 TEST ), 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 PCM connector C (49P).
Connect throttle body 6P connector terminals No. 5 and No. 6 with a jumper wire.

Fig 1: Connecting Throttle Body 6P Connector Terminals No. 5 And No. 6 With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between PCM connector terminals C2 and C3.

Fig 2: Checking Continuity Between PCM Connector Terminals C2 And C3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 27.

NO -Repair an open in the wires between the throttle body and the PCM (C2, C3), 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 PCM with the HDS.
Do the PCM idle learn procedure (see 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 PCM, then clean the throttle body (see THROTTLE BODY TEST ), 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 PCM if it does not have the latest software (see KNOCK SENSOR REPLACEMENT ), or substitute a known-good PCM (see SUBSTITUTING THE 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 PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step 1.

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