Auto Idle Stop System Auto idle stop system does not operate (With Auto Idle Stop System) (2023 2024)

Refer to: Auto Idle Stop System Description (2021 2022 2023) or Auto Idle Stop System Description - Operation Conditions (2021 2022 2023)

Auto idle stop system does not operate

NOTE: 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.

DTC check 1

-1. How to Connect the HDS , 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.

Go to step 2.

Starter system counter check:NOTE: Only if the auto idle stop system indicator (amber) blinks, check the starter system counter. If the indicator goes off, skip this step and go to the next step.
-1. Do the Starter System Counter Inspection - Refer to: Auto Idle Stop System Symptom Troubleshooting .

Is starter counter value below the specified number?

YES

The starter counter system is OK. Go to step 3.

NO

Replacing parts and clearing the starter counter according to the Proper procedure.

12 volt battery check

-1. Start the engine.

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

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
Idle Stop Inhibit (Battery Deterioration)	INHIBITED

Do the current condition(s) match the threshold?

YES

Replace the 12 volt battery - Refer to: 12 VOLT BATTERY REMOVAL, INSTALLATION, AND TEST (WITHOUT ABSORBED GLASS MAT BATTERY TYPE) or 12 VOLT BATTERY REMOVAL, INSTALLATION, AND TEST (WITH ABSORBED GLASS MAT BATTERY TYPE) .

Go to step 4.

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
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.

Go to step 5.

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 12 VOLT BATTERY INTERNAL RESISTANCE RESET , then recheck. If INHIBITED is still displayed after reset procedure, replace the 12 volt battery - Refer to: 12 VOLT BATTERY REMOVAL, INSTALLATION, AND TEST (WITH ABSORBED GLASS MAT BATTERY TYPE) or 12 VOLT BATTERY REMOVAL, INSTALLATION, AND TEST (WITHOUT ABSORBED GLASS MAT BATTERY TYPE) , then do the 12 volt battery internal resistance reset procedure 12 VOLT BATTERY INTERNAL RESISTANCE RESET , 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
Signal	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)

Signal	Current conditions
Signal	Values	Unit
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)
Idle Stop Inhibit (Barometric Air Pressure)

Is auto idle stop working?

YES

The system is OK at this time.

Go to step 6.

Starter, Brake, Charging, A/T, EPS, VSA, EBB, 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, brake system indicator, SRS indicator, electric parking brake 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 - Refer to: HOW TO TROUBLESHOOT THE FUEL AND EMISSIONS SYSTEMS or HOW TO TROUBLESHOOT THE ELECTRIC BRAKE BOOSTER SYSTEM .
  - STARTER SYSTEM CIRCUIT TROUBLESHOOTING
  - A/T system - Refer to: HOW TO TROUBLESHOOT THE A/T SYSTEM (10-SPEED A/T)
  - HOW TO TROUBLESHOOT THE SRS
  - HOW TO TROUBLESHOOT THE VSA SYSTEM
  - CHARGING SYSTEM SYMPTOM TROUBLESHOOTING INDEX
  - HOW TO TROUBLESHOOT THE EPS
  - HOW TO TROUBLESHOOT THE ELECTRIC PARKING BRAKE SYSTEM
  NO
  
  Go to step 7.
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 8.

NO

Do the following procedures:
- Do the gauge control module self-diagnostic function - Refer to: GAUGES SELF-DIAGNOSTIC FUNCTION .
- Do the A/T system symptom troubleshooting - Refer to: A/T SYSTEM SYMPTOM TROUBLESHOOTING INDEX (10-SPEED A/T) (2025) .

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.

Go to step 9.

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.

Go to step 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
Signal	Values	Unit
Brake Switch

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

YES

Go to step 11.

Test the brake pedal position switch BRAKE PEDAL POSITION SWITCH REMOVAL, INSTALLATION, AND TEST .

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) - Refer to: NETWORK COMMUNICATION DTC TROUBLESHOOTING INDEX .

Go to step 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 - Refer to: CLIMATE CONTROL SYSTEM DTC TROUBLESHOOTING INDEX .

Go to step 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 - Refer to: CLIMATE CONTROL UNIT REMOVAL AND INSTALLATION .
- If the outside air temperature reading is not accurate, check the outside air temperature sensor OUTSIDE AIR TEMPERATURE SENSOR REMOVAL, INSTALLATION, AND TEST .