NO.36 ACCELERATION MALFUNCTION [SKYACTIV-G 2.0]

id0103e6103000

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 relay malfunction (stuck open)

―  Short to ground or open circuit in electric AT oil pump relay power supply circuit

•  Short to ground in wiring harness between AT PUMP 15 A fuse and electric AT oil pump relay terminal D

•  Short to ground in wiring harness between AT PUMP 15 A fuse and electric AT oil pump relay terminal C

•  AT PUMP 15 A fuse malfunction

•  Open circuit in wiring harness between battery positive terminal and electric AT oil pump relay terminal D

•  Open circuit in wiring harness between battery positive terminal and electric AT oil pump relay terminal C

―  Electric AT oil pump connector or terminals malfunction

―  Short to ground in wiring harness between electric AT oil pump relay terminal A and electric AT oil pump terminal D

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

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

―  TCM connector or terminals malfunction

―  Short to ground in wiring harness between the following terminals:

•  Electric AT oil pump relay terminal B—TCM terminal 1K

•  Electric AT oil pump terminal C—TCM terminal 1L

•  Electric AT oil pump terminal B—TCM terminal 1N

―  Open circuit in wiring harness between the following terminals:

•  Electric AT oil pump relay terminal B—TCM terminal 1K

•  Electric AT oil pump terminal C—TCM terminal 1L

•  Electric AT oil pump terminal B—TCM terminal 1N

―  Electric AT oil pump malfunction

―  TCM malfunction

•  ATX malfunction

Hill launch assist function system (DSC) malfunction

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

―  Low-G (XY) sensor (built-into SAS control module) malfunction (In this case, the SAS control module records DTCs C1280, C1282 and C2770.)

―  Low-G (XY) sensor (built-into SAS control module) initialization malfunction (In this case, the SAS control module records DTC B2477.)

•  False detection of brake fluid pressure

―  Brake fluid pressure sensor (built-into 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 relay malfunction (stuck open) ― Short to ground or open circuit in electric AT oil pump relay power supply circuit • Short to ground in wiring harness between AT PUMP 15 A fuse and electric AT oil pump relay terminal D • Short to ground in wiring harness between AT PUMP 15 A fuse and electric AT oil pump relay terminal C • AT PUMP 15 A fuse malfunction • Open circuit in wiring harness between battery positive terminal and electric AT oil pump relay terminal D • Open circuit in wiring harness between battery positive terminal and electric AT oil pump relay terminal C ― Electric AT oil pump connector or terminals malfunction ― Short to ground in wiring harness between electric AT oil pump relay terminal A and electric AT oil pump terminal D ― Open circuit in wiring harness between electric AT oil pump terminal A and body ground ― Open circuit in wiring harness between electric AT oil pump relay terminal A and electric AT oil pump terminal D ― TCM connector or terminals malfunction ― Short to ground in wiring harness between the following terminals: • Electric AT oil pump relay terminal B—TCM terminal 1K • Electric AT oil pump terminal C—TCM terminal 1L • Electric AT oil pump terminal B—TCM terminal 1N ― Open circuit in wiring harness between the following terminals: • Electric AT oil pump relay terminal B—TCM terminal 1K • Electric AT oil pump terminal C—TCM terminal 1L • Electric AT oil pump terminal B—TCM terminal 1N ― Electric AT oil pump malfunction ― TCM malfunction • ATX malfunction Hill launch assist function system (DSC) malfunction • False detection of inclination angle (cannot calculate correct road slope) ― Low-G (XY) sensor (built-into SAS control module) malfunction (In this case, the SAS control module records DTCs C1280, C1282 and C2770.) ― Low-G (XY) sensor (built-into SAS control module) initialization malfunction (In this case, the SAS control module records DTC B2477.) • False detection of brake fluid pressure ― Brake fluid pressure sensor (built-into DSC HU/CM) malfunction • Cannot maintain brake fluid pressure ― DSC HU/CM malfunction

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	DETERMINE IF MALFUNCTION CAUSED BY ATX BODY • Compare the malfunction symptom with the i-stop system stop condition. • Is there any shock or slippage during acceleration with the i-stop system disabled?	Yes	Perform the applicable symptom troubleshooting procedure. (See SYMPTOM TROUBLESHOOTING ITEM TABLE [FW6A-EL].)
1		No	Go to the next step.
2	VERIFY DTC • Retrieve the PCM, TCM, DSC HU/CM, SAS control module DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [FW6A-EL].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) (See DTC INSPECTION.) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [SKYACTIV-G 2.0].) (See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [FW6A-EL].) (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) (See DTC TABLE.)
2		No	Go to the next step.
3	DETERMINE IF MALFUNCTION CAUSE IS BRAKE FLUID PRESSURE SENSOR SIGNAL OR OTHER • Put the vehicle in an i-stop condition (engine stopped). • Monitor the PCM PID BFP using the M-MDS while the brake is depressed and held with the i-stop function operating. (See ON-BOARD DIAGNOSIS [DYNAMIC STABILITY CONTROL (DSC)].) • Does the monitoring value change?	Yes	Brake fluid pressure sensor (built-into DSC HU/CM) or DSC HU/CM brake pressure hold function malfunction. • Replace the DSC HU/CM. (See DSC HU/CM REMOVAL/INSTALLATION.)
3		No	Go to the next step.
4	INSPECT ELECTRIC AT OIL PUMP RELAY • Switch the ignition to off. • Remove the electric AT oil pump relay. • 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 ELECTRIC AT OIL PUMP RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT • Electric AT oil pump relay is removed. • Measure the voltage at the following terminals (wiring harness-side): ― Electric AT oil pump relay terminal D ― Electric AT oil pump relay terminal C • Is the voltage B+?	Yes	Go to the next step.
5		No	Inspect the AT PUMP 15 A fuse. • If the fuse is blown: ― Repair or replace the wiring harness for a possible short to ground. ― Replace the fuse. • If the fuse is deteriorated: ― Replace the fuse. • If the fuse is normal: ― Repair or replace the wiring harness for a possible open circuit.
6	INSPECT ELECTRIC AT OIL PUMP CONNECTOR CONDITION • Disconnect the electric AT oil pump connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals.
6		No	Go to the next step.
7	INSPECT ELECTRIC AT OIL PUMP POWER SUPPLY CIRCUIT FOR SHORT TO GROUND • Electric AT oil pump relay is removed. • Verify that the electric AT oil pump connector is disconnected. • Inspect for continuity between electric AT oil pump relay terminal A (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground.
7		No	Go to the next step.
8	INSPECT ELECTRIC AT OIL PUMP GROUND CIRCUIT FOR OPEN CIRCUIT • Electric AT oil pump relay is removed. • Verify that the electric AT oil pump connector is disconnected. • Inspect for continuity between electric AT oil pump terminal A (wiring harness-side) and body ground. • Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit.
9	INSPECT ELECTRIC AT OIL PUMP POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT • Electric AT oil pump relay is removed. • Verify that the electric AT oil pump connector is disconnected. • Inspect for continuity between electric AT oil pump relay terminal A (wiring harness-side) and electric AT oil pump terminal D (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
9		No	Repair or replace the wiring harness for a possible open circuit.
10	INSPECT TCM CONNECTOR CONDITION • Disconnect the TCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals.
10		No	Go to the next step.
11	INSPECT TCM CIRCUIT FOR SHORT TO GROUND • Electric AT oil pump relay is removed. • Verify that the electric AT oil pump and TCM connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side) and body ground: ― Electric AT oil pump relay terminal B ― Electric AT oil pump terminal C ― Electric AT oil pump terminal B • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground.
11		No	Go to the next step.
12	INSPECT TCM CIRCUIT FOR OPEN CIRCUIT • Electric AT oil pump relay is removed. • Verify that the electric AT oil pump and TCM connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side): ― Electric AT oil pump relay terminal B—TCM terminal 1K ― Electric AT oil pump terminal C—TCM terminal 1L ― Electric AT oil pump terminal B—TCM terminal 1N • Is there continuity?	Yes	Replace the electric AT oil pump. (See ELECTRIC AT OIL PUMP REMOVAL/INSTALLATION [FW6A-EL].)
12		No	Repair or replace the wiring harness for a possible open circuit.
13	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.0].) • 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 [SKYACTIV-G 2.0].)