No.1 ESS (EMERGENCY STOP SIGNAL SYSTEM) DOES NOT OPERATE [ESS (EMERGENCY STOP SIGNAL SYSTEM) ]

id0903j7004200

1	ESS (Emergency stop signal system) does not operate
DESCRIPTION	•  Hazard warning lights do not flash even though the vehicle decelerates suddenly. •  Hazard warning lights end flashing before vehicle stops (vehicle speed at approx. 10 km/h {6.2 mph}) while the system operates.
POSSIBLE CAUSE	Hazard warning light flash malfunction •  BCM malfunction (flashing hazard warning light circuit malfunction) ABS CM and DSC CM do not recognize vehicle speed. •  Malfunction in ABS wheel speed sensor related parts ―  ABS wheel-speed sensor malfunction ―  ABS wheel-speed sensor rotor malfunction •  ABS CM or DSC CM malfunction BCM does not recognize sudden deceleration hazard warning mode request signal. •  ABS CM or DSC CM malfunction (signal is not output) •  BCM malfunction •  Communication error between ABS CM, DSC CM and BCM BCM does not recognize emergency stop hazard warning mode request signal. •  Brake switch signal malfunction ―  Brake switch malfunction ―  Open or short circuit between brake switch and PCM 2AO (MZR-CD (2.2)) /1AB (MZR 2.0, MZR 2.5, MZR 2.0 DISI i-stop, MZR 2.3 DISI Turbo) /1G (MZR 1.5, MZR 1.6) /1U (MZ-CD 1.6) /2G (SKYACTIV-G 2.0) •  Vehicle speed signal malfunction ―  Communication error between PCM and ABS CM, DSC CM •  BCM malfunction Road condition may be affected. (emergency stop signal system is normal) •  Grip level of tires is low ―  Driving on a low-traction surface ―  Tire wear (hydroplaning)

Diagnostic Procedure

Step	Inspection		Action
1	VERIFY DTCs •  Retrieve DTCs for the PCM, ABS CM, DSC CM, and BCM. (See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].) (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].) (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].) (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) (See ON-BOARD DIAGNOSTIC TEST [MZR 1.5, MZR 1.6].) (See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6].) (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) (See ON-BOARD DIAGNOSIS [ABS].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) (See DTC INSPECTION [BCM].) •  Are any DTCs output?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR-CD 2.2].) (See DTC TABLE [MZR 2.0, MZR 2.5].) (See DTC TABLE [MZR 2.0 DISI i-stop].) (See DTC TABLE [MZR 2.3 DISI Turbo].) (See DTC TABLE [MZR 1.5, MZR 1.6].) (See DTC TABLE [MZ-CD 1.6].) (See DTC TABLE [SKYACTIV-G 2.0].) (See ON-BOARD DIAGNOSIS [ABS].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) (See DTC TABLE [BCM].)
		No	Go to the next step.
2	VERIFY MALFUNCTION CONDITION •  Do the hazard warning lights flash in the emergency stop hazard warning mode while the vehicle speed is 10 km/h {6.2 mph} or less?	Yes	Go to the next step.
		No	Go to Step 5.
3	DETERMINE IF MALFUNCTION CAUSED BY PCM INPUT SIGNAL ERROR •  Monitor the PCM PID “BOO” using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].) (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].) (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].) (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) (See ON-BOARD DIAGNOSTIC TEST [MZR 1.5, MZR 1.6].) (See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6].) (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) •  Are the monitoring values normal?	Yes	May be affected by driving conditions (emergency stop signal system is normal). If a malfunction occurs, replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [L.H.D.].) (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [R.H.D.].)
		No	Go to the next step.
4*	INSPECT BRAKE SWITCH SIGNAL FOR MALFUNCTION CAUSED BY OPEN OR SHORT CIRCUIT •  Inspect the wiring harness between the brake switch and PCM 2AO (MZR-CD (2.2)) /1AB (MZR 2.0, MZR 2.5, MZR 2.3 DISI Turbo, MZR 2.0 DISI i-stop) /1G (MZR 1.5, MZR 1.6) /1U (MZ-CD 1.6) /2G (SKYACTIV-G 2.0) for an open or short circuit. •  Is there any open or short circuit?	Yes	Repair the malfunctioning part for an open or short circuit.
		No	Replace the brake switch. (See BRAKE PEDAL REMOVAL/INSTALLATION [L.H.D.].) (See BRAKE PEDAL REMOVAL/INSTALLATION [R.H.D.].)
5	INSPECT FLASHING HAZARD WARNING LIGHT CIRCUIT FOR MALFUNCTION •  Flashes the hazard warning lights using the hazard warning switch. •  Do the hazard warning lights flash?	Yes	Go to the next step.
		No	Replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [L.H.D.].) (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [R.H.D.].)
6	DETERMINE IF MALFUNCTION CAUSED BY ABS OPERATION MALFUNCTION •  Inspect the ABS operation at 10—20 km/h {6.2—12.0 mph}. •  Is the ABS operation normal?	Yes	System may be affected by road conditions (emergency stop signal system is normal). If the malfunction recurs, replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [L.H.D.].) (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [R.H.D.].)
		No	•  Inspect the tires for the following: ―  Tire air pressure (are all four tires at recommended pressure?) ―  Tire wear condition (is tire wear uniform on all four tires, or is it different?) ―  Tire size Adjust the malfunctioning tire or replace it.