ACCELERATION MALFUNCTION [SKYACTIV-X]

id1103c0002600

Troubleshooting item

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
Note
•  MTX vehicles are not included because the driver releases the brake pedal and depresses the clutch pedal to accelerate.
Hill launch assist function system (DSC) malfunction
•  False detection of inclination angle (cannot calculate correct road slope)
―  Low-G sensor (built-into SAS control module) malfunction (In this case, the SAS control module records DTCs C0061:29 and C0062:29.)
―  Low-G 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 electronically controlled brake unit) malfunction
•  Cannot maintain brake fluid pressure
―  Electronically controlled brake unit malfunction
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
―  Electric AT oil pump connector or terminals malfunction
―  Open circuit in electric AT oil pump ground circuit
―  Short to ground in electric AT oil pump power supply circuit
―  Open circuit in electric AT oil pump power supply circuit
―  TCM connector or terminals malfunction
―  Short to ground in any of the following circuits.
•  TCM power supply circuit
•  TCM signal circuit
―  Open circuit in any of the following circuits.
•  TCM power supply circuit
•  TCM signal circuit
―  Electric AT oil pump malfunction
―  TCM malfunction
•  ATX 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 [ET6A-EL, ET6AX-EL].)
No
Go to the next step.
2
VERIFY DTC
•  Perform the DTC inspection for the following modules.
―  PCM
―  TCM
―  Electronically controlled brake unit
―  SAS control module
•  Are any DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
(See DTC TABLE [PCM (SKYACTIV-X)].)
(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [TCM (ET6A-EL, ET6AX-EL) (E)].)
(See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
(See DTC TABLE [SAS CONTROL MODULE].)
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 BRK_FLD_PRES using the M-MDS while the brake is depressed and held with the i-stop function operating.
•  Does the monitoring value change?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)
•  If the CAN communication is normal, repeat the inspection from Step 1.
―  If the malfunction recurs, perform the following procedure.
•  Replace the electronically controlled brake unit. (Brake fluid pressure sensor (built-into electronically controlled brake unit) or electronically controlled brake unit brake pressure hold function malfunction.)
―  Perform the repair completion verification 1.
No
Go to the next step.
4
INSPECT ELECTRIC AT OIL PUMP RELAY FOR MALFUNCTION
•  Inspect the applicable part.
•  Is the part normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
(See RELAY LOCATION [(E)].)
5
INSPECT ELECTRIC AT OIL PUMP RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT
•  Inspect the applicable circuit for an open circuit and short to ground.
•  Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
6
INSPECT ELECTRIC AT OIL PUMP CONNECTOR FOR MALFUNCTION
•  Inspect the applicable connector and terminal.
•  Are the connector and terminal normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
7
INSPECT ELECTRIC AT OIL PUMP GROUND CIRCUIT FOR OPEN CIRCUIT
•  Inspect the applicable circuit for an open circuit.
•  Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
8
INSPECT ELECTRIC AT OIL PUMP POWER SUPPLY CIRCUIT FOR SHORT TO GROUND
•  Inspect the applicable circuit for a short to ground.
•  Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
9
INSPECT ELECTRIC AT OIL PUMP POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT
•  Inspect the applicable circuit for an open circuit.
•  Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
10
INSPECT TCM CONNECTOR FOR MALFUNCTION
•  Inspect the applicable connector and terminal.
•  Are the connector and terminal normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
11
INSPECT TCM POWER SUPPLY CIRCUIT AND SIGNAL CIRCUIT FOR SHORT TO GROUND
•  Inspect the applicable circuit for a short to ground.
•  Is the circuit normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
12
INSPECT TCM POWER SUPPLY CIRCUIT AND SIGNAL CIRCUIT FOR OPEN CIRCUIT
•  Inspect the applicable circuit for an open circuit.
•  Is the circuit normal?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)
•  If the CAN communication is normal, perform the diagnosis from Step 1.
―  If the malfunction recurs, replace the electric AT oil pump, then perform the repair completion verification 1.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
Repair completion verification 1
VERIFY THAT VEHICLE IS REPAIRED
•  Install/connect the part removed/disconnected during the troubleshooting procedure.
•  Has the malfunction symptom been eliminated?
Yes
Complete the symptom troubleshooting. (Explain contents of repair to customer)
No
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)
•  If the CAN communication is normal, perform the diagnosis from Step 1.
―  If the malfunction recurs, go to the next step.
Repair completion verification 2
VERIFY IF MALFUNCTION IS CAUSED BY NOT PERFORMING PCM REPROGRAMMING
•  Verify repair information and verify that there is a new calibration in the PCM.
•  Is there a new calibration in the PCM?
Yes
Perform the PCM reprogramming and verify if the malfunction symptom was corrected.
•  If the malfunction recurs, replace the PCM.
No
Replace the PCM.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)