NO.9 ACCELERATION MALFUNCTION [SKYACTIV-G 2.5T]

id1103b2001400

9	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 MAIN 200 A fuse and electric AT oil pump relay terminal D • MAIN 200 A fuse and/or AT PUMP 15 A fuse malfunction • Open circuit in wiring harness between battery positive terminal and electric AT oil pump relay terminal D ? Short to ground or open circuit in electric AT oil pump relay power supply circuit • Short to ground in wiring harness between ENGINE3 15 A fuse and electric AT oil pump relay terminal A • ENGINE3 15 A fuse malfunction • Open circuit in wiring harness between main relay terminal C and electric AT oil pump relay terminal A ? Electric AT oil pump connector or terminals malfunction ? Open circuit in wiring harness between electric AT oil pump terminal A and body ground ? Short to ground in wiring harness between electric AT oil pump relay terminal C and electric AT oil pump terminal D ? Open circuit in wiring harness between electric AT oil pump relay terminal C 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 E—TCM terminal K • Electric AT oil pump terminal C—TCM terminal L • Electric AT oil pump terminal B—TCM terminal N ? Open circuit in wiring harness between the following terminals: • Electric AT oil pump relay terminal E—TCM terminal K • Electric AT oil pump terminal C—TCM terminal L • Electric AT oil pump terminal B—TCM terminal N ? 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 C0061:29 and C0062:29.) ? Low-G (XY) sensor (built-into SAS control module) initialization malfunction (In this case, the SAS control module records DTC U2100:00.) • 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

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 MAIN 200 A fuse and electric AT oil pump relay terminal D

• MAIN 200 A fuse and/or AT PUMP 15 A fuse malfunction

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

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

• Short to ground in wiring harness between ENGINE3 15 A fuse and electric AT oil pump relay terminal A

• ENGINE3 15 A fuse malfunction

• Open circuit in wiring harness between main relay terminal C and electric AT oil pump relay terminal A

? Electric AT oil pump connector or terminals malfunction

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

? Short to ground in wiring harness between electric AT oil pump relay terminal C and electric AT oil pump terminal D

? Open circuit in wiring harness between electric AT oil pump relay terminal C 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 E—TCM terminal K

• Electric AT oil pump terminal C—TCM terminal L

• Electric AT oil pump terminal B—TCM terminal N

? Open circuit in wiring harness between the following terminals:

• Electric AT oil pump relay terminal E—TCM terminal K

• Electric AT oil pump terminal C—TCM terminal L

• Electric AT oil pump terminal B—TCM terminal N

? 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 C0061:29 and C0062:29.)

? Low-G (XY) sensor (built-into SAS control module) initialization malfunction (In this case, the SAS control module records DTC U2100:00.)

• 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 [GW6A-EL, GW6AX-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 [PCM (SKYACTIV-G 2.5T)].) (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (GW6A-EL, GW6AX-EL)].) (See DTC INSPECTION [DSC HU/CM].) (See DTC INSPECTION [SAS CONTROL MODULE].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.5T)].) (See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [TCM (GW6A-EL, GW6AX-EL)].) (See DTC TABLE [DSC HU/CM].) (See DTC TABLE [SAS CONTROL MODULE].)
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 PID/DATA MONITOR INSPECTION (i-stop) [SKYACTIV-G 2.5T].) • 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, then go to step 14. (See DSC HU/CM REMOVAL/INSTALLATION.)
3		No	Go to the next step.
4	INSPECT ELECTRIC AT OIL PUMP RELAY • Switch the ignition off. • Remove the electric AT oil pump relay. (See RELAY LOCATION.) • Inspect the electric AT oil pump relay. (See RELAY INSPECTION.) • Is there any malfunction?	Yes	Replace the electric AT oil pump relay, then go to step 14.
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 electric AT oil pump relay terminal D (wiring harness-side). • Is the voltage B+?	Yes	Go to the next step.
5		No	Inspect the MAIN 200 A fuse and AT PUMP 15 A fuse. • If the fuse is blown: ? Refer to the wiring diagram and verify whether or not there is a common connector between MAIN 200 A fuse and electric AT oil pump relay terminal D. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to ground. • Replace the malfunctioning fuse. • If the fuse is damaged: ? Replace the malfunctioning fuse. • If all fuses are normal: ? Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and electric AT oil pump relay terminal D. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to step 14.
6	INSPECT ELECTRIC AT OIL PUMP RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT • Electric AT oil pump relay is removed. • Switch the ignition ON (engine off). • Measure the voltage at the electric AT oil pump relay terminal A (wiring harness-side). • Is the voltage B+?	Yes	Go to the next step.
6		No	Inspect the ENGINE3 15 A fuse. • If the fuse is blown: ? Refer to the wiring diagram and verify whether or not there is a common connector between ENGINE3 15 A fuse and electric AT oil pump relay terminal A. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to ground. • Replace the fuse. • If the fuse is damaged: ? Replace the fuse. • If the fuse is normal: ? Refer to the wiring diagram and verify whether or not there is a common connector between main relay terminal C and electric AT oil pump relay terminal A. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to step 14.
7	INSPECT ELECTRIC AT OIL PUMP CONNECTOR CONDITION • Switch the ignition off. • 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, then go to step 14.
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	Refer to the wiring diagram and verify whether or not there is a common connector between electric AT oil pump terminal A and body ground. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Inspect for the following: ? Open circuit between electric AT oil pump and body ground ? Loose or lifting ground point • Repair or replace the malfunctioning part. Go to step 14.
9	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 C (wiring harness-side) and body ground. • Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between electric AT oil pump relay terminal C and electric AT oil pump terminal D. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to ground. Go to step 14.
9		No	Go to the next step.
10	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 C (wiring harness-side) and electric AT oil pump terminal D (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
10		No	Refer to the wiring diagram and verify whether or not there is a common connector between electric AT oil pump relay terminal C and electric AT oil pump terminal D. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to step 14.
11	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, then go to step 14.
11		No	Go to the next step.
12	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 E ? Electric AT oil pump terminal C ? Electric AT oil pump terminal B • Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Electric AT oil pump relay terminal E—TCM terminal K • Electric AT oil pump terminal C—TCM terminal L • Electric AT oil pump terminal B—TCM terminal N If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to ground. Go to step 14.
12		No	Go to the next step.
13	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 E—TCM terminal K ? Electric AT oil pump terminal C—TCM terminal L ? Electric AT oil pump terminal B—TCM terminal N • Is there continuity?	Yes	Replace the electric AT oil pump, then go to the next step. (See ELECTRIC AT OIL PUMP REMOVAL/INSTALLATION [GW6A-EL, GW6AX-EL].)
13		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Electric AT oil pump relay terminal E—TCM terminal K • Electric AT oil pump terminal C—TCM terminal L • Electric AT oil pump terminal B—TCM terminal N If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to the next step.
14	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5T].) • 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 2.5T].)