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

id0103d3103000

36

ACCELERATION MALFUNCTION

DESCRIPTION

•  Acceleration from i-stop is not smooth.

•  Suppresses (shock) when accelerating vehicle from i-stop.

•  Engine vibration increases when engine is restarted.

POSSIBLE CAUSE

ATX system malfunction

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

―  Electric AT oil pump driver malfunction

―  Electric AT oil pump malfunction

―  Electric AT oil pump relay malfunction (stuck open)

―  Open circuit in wiring harness between electric AT oil pump relay terminal D and body ground

―  Open circuit in wiring harness between electric AT oil pump driver terminal 1C and body ground

―  Short or open circuit in wiring harness between electric AT oil pump driver and electric AT oil pump

―  Short or open circuit in wiring harness between main battery positive terminal and electric AT oil pump relay terminal A

―  Short or open circuit in wiring harness between electric AT oil pump relay terminal B and PCM terminal 1F

―  Short or open circuit in wiring harness between electric AT oil pump relay terminal C and electric AT oil pump driver terminal 1A

―  Short or open circuit in wiring harness between electric AT oil pump driver terminal 1B and PCM terminal 1AF

•  ATX malfunction

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

36	ACCELERATION MALFUNCTION
DESCRIPTION	• Acceleration from i-stop is not smooth. • Suppresses (shock) when accelerating vehicle from i-stop. • Engine vibration increases when engine is restarted.
POSSIBLE CAUSE	ATX system malfunction • Electric AT oil pump malfunction (operation malfunction, insufficient pressure) ― Electric AT oil pump driver malfunction ― Electric AT oil pump malfunction ― Electric AT oil pump relay malfunction (stuck open) ― Open circuit in wiring harness between electric AT oil pump relay terminal D and body ground ― Open circuit in wiring harness between electric AT oil pump driver terminal 1C and body ground ― Short or open circuit in wiring harness between electric AT oil pump driver and electric AT oil pump ― Short or open circuit in wiring harness between main battery positive terminal and electric AT oil pump relay terminal A ― Short or open circuit in wiring harness between electric AT oil pump relay terminal B and PCM terminal 1F ― Short or open circuit in wiring harness between electric AT oil pump relay terminal C and electric AT oil pump driver terminal 1A ― Short or open circuit in wiring harness between electric AT oil pump driver terminal 1B and PCM terminal 1AF • ATX malfunction 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

Diagnostic procedure

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].)
1		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.
2		No	Go to the next step.
3	Compare the malfunction symptom with the i-stop system stop condition. Does any shock or slippage occur when accelerating and when the i-stop system is stopped?	Yes	Perform the applicable symptom troubleshooting procedure. (See SYMPTOM TROUBLESHOOTING ITEM TABLE [FS5A-EL].)
3		No	Go to the next step.
4	Inspect the electric AT oil pump relay. (See RELAY INSPECTION.) Is there any malfunction?	Yes	Replace the electric AT oil pump relay.
4		No	Go to the next step.
5	Inspect the following wiring harness. • Between PCM terminal 1F and electric AT oil pump relay terminal B • Between electric AT oil pump relay terminal D and body ground Is there any malfunction?	Yes	Repair or replace the wiring harness.
5		No	Go to the next step.
6	Start the engine and it at idle. Access the TCM PID OP_SW_B using the M-MDS. (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [FS5A-EL].) Is the PID value normal?	Yes	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.)
6		No	Go to the next step.
7	Inspect the oil pressure switch. (See OIL PRESSURE SWITCH INSPECTION [FS5A-EL].) Is there any malfunction?	Yes	Replace the oil pressure switch. (See OIL PRESSURE SWITCH REMOVAL/INSTALLATION [FS5A-EL].)
7		No	Go to the next step.
8	Inspect the wiring harness between oil pressure switch and TCM terminal S for a short or open circuit. Is there any malfunction?	Yes	Repair or replace the wiring harness.
8		No	Go to the next step.
9	Inspect the ENG BAR AT PUMP 25 A fuse. Is there any malfunction?	Yes	If the fuse is melt: • Repair or replace the wiring harness between main battery positive terminal and electric AT oil pump driver terminal 1A for a possible short to ground. • Replace the fuse. If the fuse is deterioration: • Replace the fuse.
9		No	Go to the next step.
10	Inspect the wiring harness between main battery positive terminal and electric AT oil pump driver terminal 1A (wiring harness-side) for a short or open circuit. Is there any malfunction?	Yes	Repair or replace the wiring harness.
10		No	Go to the next step.
11	Disconnect the electric AT oil pump driver connector. Inspect for continuity between electric AT oil pump driver terminal 1C (wiring harness-side) and body ground. Is there continuity?	Yes	Go to the next step.
11		No	Repair or replace the wiring harness for a possible open circuit and/or poor contact ground point.
12	Electric AT oil pump driver connector is disconnected. Disconnect the PCM connector. Inspect the wiring harness between electric AT oil pump relay terminal 1B (wiring harness-side) and PCM terminal 1AF (wiring harness-side) for a short or open circuit. Is there any malfunction?	Yes	Repair or replace the wiring harness.
12		No	Go to the next step.
13	Inspect the electric AT oil pump. (See ELECTRIC AT OIL PUMP INSPECTION [FS5A-EL].) Is there any malfunction?	Yes	Replace the electric AT oil pump. (See ELECTRIC AT OIL PUMP REMOVAL/INSTALLATION [FS5A-EL].)
13		No	Repair or replace malfunctioning part according to inspection result.
14	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].)