Auto idle stop system does not operate (With Auto Idle Stop System) (2018 2019 2020)

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) .
• 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

   -1. 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
   P154A Battery Sensor Internal Failure
   P154B Battery Sensor Characteristic Abnormal
   P154D PCM Low Voltage at Engine Auto Restart
   P16E3 PGM-FI-Battery Sensor LIN Communication Error

   Is DTC P154A, P154B, P154D, 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 .

   NO 

   Go to step 3.

3. DTC check 2

   -1. Check for Pending or Confirmed DTCs with the HDS.

   NOTE:  The low atmospheric pressure caused by the high altitudes can inhibit the auto idle stop.

   DTC Description	Confirmed DTC	Pending DTC
   P2226 BARO Sensor Circuit Malfunction
   P2227 BARO Sensor Circuit Out of Range High

   DTC Description	Confirmed DTC	Pending DTC
   P2228 BARO Sensor Circuit Low Voltage
   P2229 BARO Sensor Circuit High Voltage

   Is DTC P2226, P2227, P2228, and/or P2229 indicated?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   Go to step 4.

4. Problem verification:

   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 , 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)

   Signal	Current conditions
   	Values	Unit
   Idle Stop Inhibit (Inclined State)
   Idle Stop Inhibit (Operating Condition)
   Idle Stop Inhibit (Barometric Air Pressure)

   Is auto idle stop working?

   YES 

   The system is OK at this time.

   NO 

   Go to step 5.

5. Starter, Brake, Charging, A/T, EPS, VSA, SRS, electric parking brake system, 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, shift position indicator, EPS indicator, VSA indicator, SRS indicator, electric parking brake indicator, and MIL indicator stay on or are any DTCs set?

   YES 

   Do the troubleshooting for the system that indicator stays on.

   • PGM-FI system
   • Starter system
   • A/T system
   • Brake system
   • SRS
   • VSA system
   • Charging system
   • EPS system
   • Electric parking brake system

   NO 

   Go to step 6.

6. Shift position indicator check

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

   Does shift position indicator come on?

   YES 

   Go to step 7.

   NO 

   Do the following procedures:

   • Do the gauge control module self-diagnostic function .
   • Do the A/T system symptom troubleshooting .
7. SRS 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 SRS with the HDS.

   DTC Description	Confirmed DTC

   Are any DTCs indicated?

   YES 

   Go to the indicated DTC's troubleshooting .

   NO 

   Go to step 8.

8. Electric parking brake system check

   -1. Select the VSA system with the HDS.

   -2. Check for DTCs with the HDS.

   DTC Description	DTC

   Are any DTCs related to the electric parking brake system indicated?

   YES 

   Go to the indicated DTC's troubleshooting .

   NO 

   Go to step 9.

9. Brake booster check

   -1. Do the 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 

    Test the brake pedal position switch .

11. Body electrical system DTC check

    -1. Check for body electrical system DTCs with the HDS.

    DTC Description	Confirmed DTC

    Are any DTCs related to the power distribution module indicated?

    YES 

    Go to the troubleshooting for the body electrical system DTC(s) .

    NO 

    Go to step 12.

12. Climate control 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

    Are any DTCs indicated?

    YES 

    Go to the indicated DTC's troubleshooting .

    NO 

    Go to step 13.

13. Climate control unit check

    -1. Turn the vehicle to the ON mode.

    -2. Check the outside air temperature displayed in the gauge control module.

    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 , then recheck. If the auto idle stop system is OK, replace the original climate control unit .
    • If the outside air temperature reading is not accurate, check the outside air temperature sensor .