DTC P15C4: Auto Idle Stop System Malfunction (CVT model)

NOTE:

Before you troubleshoot, record all freeze data, and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
If the DTC cannot be cleared, do the troubleshooting for DTC U1204.
This DTC is stored when the auto idle stop is prohibited due to failure.

Turn the ignition switch to ON (II).
Clear the DTC with the HDS (see DTC CLEAR ).
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0102 indicated?

YES -Do the troubleshooting for DTC P0102 (see DTC P0102: MAF SENSOR CIRCUIT LOW VOLTAGE ), then reset the PCM with the HDS (see IF THE MIL DID NOT STAY ON ).

NO -Go to step 4.
Check the AUTO IDLE STOP DOES NOT OCCUR (BRAKE) in the PGM-FI SYSTEM with the HDS.
Does the HDS indicate EXIST?

YES -Go to the brake booster pressure monitoring system's general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). When the brake booster pressure monitoring system troubleshooting is completed, clear the DTC (see DTC CLEAR ).

NO -Go to step 5.
Check the AUTO IDLE STOP DOES NOT OCCUR (A/C) in the PGM-FI SYSTEM with the HDS.
Does the HDS indicate EXIST?

YES -Go to the climate control system's general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). When the climate control system troubleshooting is completed, clear the DTC (see DTC CLEAR ).

NO -Go to step 6.
Check the IDLE STOP SW in the PGM-FI DATA LIST with the HDS.
Does it indicate OPEN when the brake pedal is pressed and CLOSE when the brake pedal is released?

YES -The system is OK at this time. Go to step 20.

NO -
- If CLOSE stays on, go to step 7.
- If OPEN stays on, go to step 10.
Turn the ignition switch to LOCK (0).
Disconnect the idle stop switch 2P connector.
Check the IDLE STOP SW in the PGM-FI DATA LIST with the HDS.
Does the HDS indicate OPEN?

YES -Replace the idle stop switch (see IDLE STOP SWITCH REPLACEMENT ), then go to step 19.

NO -Repair a short to power in the wire between the idle stop switch 2P connector and the PCM (A13), then go to step 19.
Turn the ignition switch to LOCK (0).
Disconnect the idle stop switch 2P connector.
Connect idle stop switch 2P connector terminals No. 1 and No. 2 with a jumper wire.

Fig 1: Identifying Jumper Wire Connection With Idle Stop Switch 2P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Check the IDLE STOP SW in the PGM-FI DATA LIST with the HDS.
Does the HDS indicate CLOSE?

YES -Replace the idle stop switch (see IDLE STOP SWITCH REPLACEMENT ), then go to step 19.

NO -Go to step 15.
Turn the ignition switch to LOCK (0).
Disconnect the jumper wire from the idle stop switch 2P connector.
Turn the ignition switch to ON (II).
Measure the voltage between body ground and idle stop switch 2P connector terminal No. 1.

Fig 2: Measuring Voltage Between Body Ground And Idle Stop Switch 2P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Repair an open in the wire between the idle stop switch 2P connector and the PCM (A13), then go to step 19.

NO -Repair an open in the wire between the No. B12 IMA (10 A) fuse and the idle stop switch 2P connector, then go to step 19.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS (see IF THE MIL DID NOT STAY ON ).
NOTE: If the PCM is not reset, DTC P15C4 can return.
Clear the DTC with the HDS (see DTC CLEAR ).
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P15C4 indicated?

YES -Check for poor connections or loose terminals at the PCM and the idle stop switch. Also check for brake system and climate control system DTCs, then go to step 1.

NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC'S TROUBLESHOOTING .