Auto Idle Stop System - Auto Idle Stop System Does Not Operate

NOTE: 

• If the auto idle stop system indicator (amber) blinks, go to the auto idle stop system symptom troubleshooting (Auto idle stop system indicator blinks) - Go to the: Auto Idle Stop System Symptom Troubleshooting - Auto idle stop system indicator (AMBER) blinks .
• When the 12 volt battery terminals are loose or corroded or an aftermarket electronic device is directly connected to the 12 volt battery negative terminal, the vehicle may wrongly detect the battery deterioration and this symptom may appear. Check for these conditions of the 12 volt battery terminals listed above before you troubleshoot and fix them as needed, then make sure that the indicator goes off when you start up the engine.

1. DTC check

   -1. Connect the HDS Connect The HDS  to the DLC, then select the PGM-FI system with the HDS.

   - 2. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   P154A Battery Sensor Internal Failure
   P16E3 PGM-FI-Battery Sensor LIN Communication Error
   P16E7 Battery Blower LIN Communication Error

   Is DTC P154A and/or P16E3 indicated?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   Go to step 2.

2. 12 volt battery check

   -1. Start the engine.

   - 2. Check the parameter(s) below with the HDS.

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   IDLE STOP INHIBIT (BATTERY DETERIORATION)	INHIBITED

   Do the current condition(s) match the threshold?

   YES 

   Replace the 12 Volt Battery - Removal and Installation .

   NO 

   Go to step 3.

3. Problem verification

   -1. Do the Auto Idle Stop System  inspection.

   NOTE: 

   • Some prohibited condition of the auto idle stop system can be checked by the parameter of the HDS. Check the following parameters while a vehicle stops. If the parameter is indicated INHIBITED, the auto idle stop is prohibited by its item.
   • If the IDLE STOP INHIBIT (BATTERY DETERIORATION) is INHIBITED, do the 12 Volt Battery Internal Resistance Reset procedure, then recheck. If INHIBITED is still displayed after reset procedure, replace the 12 Volt Battery - Removal and Installation , then do the 12 Volt Battery Internal Resistance Reset procedure, and recheck.
   • There is a parameter that is not supported by the application. Parameters that are not supported will not be displayed.

   Signal	Current conditions
   	Values	Unit
   IDLE STOP INHIBIT (EPS UNIT)
   IDLE STOP INHIBIT (ABS/VSA UNIT)
   IDLE STOP INHIBIT (HVAC)
   IDLE STOP INHIBIT (BATTERY MANAGEMENT SYSTEM)
   IDLE STOP INHIBIT (BRAKE SYSTEM)
   IDLE STOP INHIBIT (DC-DC CONVERTER)
   IDLE STOP INHIBIT (IDLE STOP CANCEL SWITCH)
   IDLE STOP INHIBIT (HOOD OPEN)
   IDLE STOP INHIBIT (SEAT BELT UNFASTENED)
   IDLE STOP INHIBIT (PCU)
   IDLE STOP INHIBIT (BATTERY DETERIORATION)
   IDLE STOP INHIBIT (AT/CVT: PRECONDITION)
   IDLE STOP INHIBIT (AT/CVT: TRANSITION CONDITION)
   IDLE STOP INHIBIT (LOW BATTERY VOLTAGE)
   IDLE STOP INHIBIT (HOOD OPEN HISTORY)
   IDLE STOP INHIBIT (DRIVING HISTORY)
   IDLE STOP INHIBIT (PRECONDITION)
   IDLE STOP INHIBIT (INCLINED STATE)
   IDLE STOP INHIBIT (OPERATING CONDITION)

   Is auto idle stop working?

   YES 

   The system is OK at this time.

   NO 

   Go to step 4.

4. Starter, Brake, Charging, A/T, EPS, VSA, PGM-FI system check

   -1. Start the engine, and check the indicator on the gauge, and check for any DTC with the HDS.

   Do Charging system indicator, A/T gear position indicator, EPS indicator, VSA indicator, and MIL indicator stay on or are any DTCs set?

   1. YES 

      Do the troubleshooting for the system that indicator stays on.

      • PGM-FI system - Go to: How to Troubleshoot the Fuel and Emissions Systems .
      • Starter System
      • A/T system - Go to: How to Troubleshoot the A/T System (6-Speed A/T) .
      • Brake system - Go to: How to Troubleshoot the Brake Booster Pressure Monitoring System
      • VSA System
      • Charging System
      • EPS System

      NO 

      Go to step 5.

5. A/T system check

   -1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Turn the vehicle to the ON mode.

   - 3. Check for Pending or Confirmed DTCs in the A/T system with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame

   DTC (A/T)

   Are any Pending or Confirmed DTCs indicated?

   YES 

   Go to the indicated DTC's troubleshooting - Refer to:

   A/T System DTC Troubleshooting Index (6-Speed A/T) (2016 2017 2018) or

   A/T System DTC Troubleshooting Index (6-Speed A/T) (2019 2020) .

   NO 

   Go to step 6.

6. A/C system check

   -1. Select the BODY ELECTRICAL system with the HDS.

   - 2. Select the HVAC/Climate Control, then check for DTCs with the HDS.

   DTC Description	DTC

   DTC (AC)

   Are any DTCs indicated?

   YES 

   Go to the indicated: Climate Control System DTC Troubleshooting Index .

   NO 

   Go to step 7.

7. A/T gear position indicator check

   -1. Shift the transmission to D position/mode while pressing the brake pedal firmly.

   Does A/T gear position indicator come on?

   YES 

   Go to step 8.

   NO 

   Do the following procedures.

   • Do the gauge control module self-diagnostic function - Refer to: or.

     Gauges Self-Diagnostic Function (2016 2017 2018) .

     Gauges Self-Diagnostic Function (2019 2020 2021)

   • Do the automatic transmission symptom troubleshooting - Refer to:

     A/T System Symptom Troubleshooting Index (6-Speed A/T) (2016 2017 2018 2019 2020) or

     A/T System Symptom Troubleshooting Index (9-Speed A/T) (2016 2017 2018) or

     A/T System Symptom Troubleshooting Index (9-Speed A/T) (2019 2020 2021) .

8. Starter system check

   -1. Check the indicator on the gauge and stored DTC.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame

   DTC (PGM-FI)

   Is the starter system indication indicated, or are any DTCs stored?

   YES 

   Do the troubleshooting for the starter system - Refer to:

   Fuel and Emissions Systems DTC Troubleshooting Index (KA/KC) (2016 2017 2018 2019 2020) or

   Fuel and Emissions Systems DTC Troubleshooting Index (2021) .

   NO 

   Go to step 9.

9. Brake booster check

   -1. Do the brake booster inspection. Brake Booster Test

   Is the brake booster OK?

   YES 

   Go to step 10.

   NO 

   Replace any leaking part(s) as needed.

10. Brake pedal position switch signal check

    -1. Turn the vehicle to the ON mode.

    - 2. Check the parameter(s) below with the HDS.

    Signal	Current conditions
    	Values	Unit
    BRAKE SWITCH

    Does the signal change ON and OFF when the brake pedal is pressed and released?

    YES 

    Go to step 11.

    NO 

    Do the Brake Pedal Position Switch Test .

11. Climate control unit check

    -1. Turn the vehicle to the ON mode.

    - 2. Check the outside air temperature displayed in the MID.

    Is the outside air temperature reading accurate?

    YES 

    The system is OK at this time.

    NO 

    • If the outside air temperature is not indicated, substitute a known-good Climate Control Unit - Removal and Installation , then recheck. If the auto idle stop system is OK, replace the original Climate Control Unit - Removal and Installation .
    • If the outside air temperature reading is not accurate, check the Outside Air Temperature Sensor - Removal and Installation, Test .