NO.37 VEHICLE MOVES WHEN ACCELERATING FROM STANDSTILL ON SLOPE [MZR 2.0 DISI i-stop]

37	VEHICLE MOVES WHEN ACCELERATING FROM STANDSTILL ON SLOPE
DESCRIPTION	• Vehicle slips backwards on inclined road surface when accelerating after i-stop operates.
POSSIBLE CAUSE	Note • i-stop (engine-stop control) continues operating when shifting the selector lever from D range to N or P position while i-stop (engine-stop control) is operating, however, if the slope of the road surface is within ±4 %, the Hill Launch Assist (HLA) function is canceled. Hill launch assist function system (DSC) malfunction • False detection of inclination angle (cannot calculate correct road slope) ― Low-G (XY) sensor (built-in SAS control module) malfunction ― Low-G (XY) sensor (built-in SAS control module) initialization malfunction • False detection of brake fluid pressure ― Brake fluid pressure sensor (built-in DSC HU/CM) malfunction • Cannot maintain brake fluid pressure ― DSC HU/CM malfunction ATX system malfunction • Electric AT oil pump malfunction (operation malfunction, insufficient pressure) • ATX malfunction

VEHICLE MOVES WHEN ACCELERATING FROM STANDSTILL ON SLOPE

DESCRIPTION

• Vehicle slips backwards on inclined road surface when accelerating after i-stop operates.

POSSIBLE CAUSE

Note

• i-stop (engine-stop control) continues operating when shifting the selector lever from D range to N or P position while i-stop (engine-stop control) is operating, however, if the slope of the road surface is within ±4 %, the Hill Launch Assist (HLA) function is canceled.

Hill launch assist function system (DSC) malfunction

• False detection of inclination angle (cannot calculate correct road slope)

― Low-G (XY) sensor (built-in SAS control module) malfunction

― Low-G (XY) sensor (built-in SAS control module) initialization malfunction

• False detection of brake fluid pressure

― Brake fluid pressure sensor (built-in DSC HU/CM) malfunction

• Cannot maintain brake fluid pressure

― DSC HU/CM malfunction

ATX system malfunction

• Electric AT oil pump malfunction (operation malfunction, insufficient pressure)

• ATX malfunction

STEP	INSPECTION	RESULTS	ACTION
1	Retrieve the PCM, TCM, DSC HU/CM, SAS control module DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].) (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FS5A-EL].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) (See DTC INSPECTION [TYPE B].) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR 2.0 DISI i-stop].) (See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [FS5A-EL].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) (See DTC TABLE [TYPE B].)
No	Go to the next step.
2	Perform the initialization of the low-G (XY) sensor. (See DSC SENSOR INITIALIZATION PROCEDURE.) Has the malfunction symptom been eliminated?	Yes	Malfunction caused by the low-G (XY) sensor initialization malfunction. • Symptom troubleshooting is completed.
No	Go to the next step.
3	Verify the malfunction symptom on a flat road surface. Does the acceleration lag when accelerating?	Yes	Perform the symptom troubleshooting “NO.36 ACCELERATION MALFUNCTION”. (See NO.36 ACCELERATION MALFUNCTION [MZR 2.0 DISI i-stop].)
No	Brake fluid pressure sensor (built-in DSC HU/CM) or DSC HU brake pressure hold function malfunction. • Replace the DSC HU/CM. (See DSC HU/CM REMOVAL/INSTALLATION.)
4	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI i-stop].) • If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis. ― If the vehicle is repaired, troubleshooting is completed. ― If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)

STEP

INSPECTION

RESULTS

ACTION

Retrieve the PCM, TCM, DSC HU/CM, SAS control module DTCs using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)

(See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FS5A-EL].)

(See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)

(See DTC INSPECTION [TYPE B].)

Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [MZR 2.0 DISI i-stop].)

(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [FS5A-EL].)

(See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].)

(See DTC TABLE [TYPE B].)

Go to the next step.

Perform the initialization of the low-G (XY) sensor.

(See DSC SENSOR INITIALIZATION PROCEDURE.)

Has the malfunction symptom been eliminated?

Yes

Malfunction caused by the low-G (XY) sensor initialization malfunction.

• Symptom troubleshooting is completed.

Go to the next step.

Verify the malfunction symptom on a flat road surface.

Does the acceleration lag when accelerating?

Yes

Perform the symptom troubleshooting “NO.36 ACCELERATION MALFUNCTION”.

(See NO.36 ACCELERATION MALFUNCTION [MZR 2.0 DISI i-stop].)

Brake fluid pressure sensor (built-in DSC HU/CM) or DSC HU brake pressure hold function malfunction.

• Replace the DSC HU/CM.

(See DSC HU/CM REMOVAL/INSTALLATION.)

Verify the test results.

• If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI i-stop].)

• If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis.

― If the vehicle is repaired, troubleshooting is completed.

― If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)