ACCELERATION MALFUNCTION [SKYACTIV-D]


id1103sc002600

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.
A/C system malfunction
•  Improper A/C system operation
―  A/C compressor malfunction
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 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)
―  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
•  Lack of ATF
Brake system malfunction
•  Brake dragging
Engine system malfunction
•  Drive belt shear, deviation, or wear
•  Fuel injection system malfunction
―  Fuel leakage from fuel system
―  Common rail malfunction
―  Supply pump malfunction
―  Suction control valve malfunction
―  Fuel injector malfunction
―  Fuel pressure relief valve malfunction
―  Fuel filter clogging
―  Fuel check valve or fuel feed valve malfunction
•  Poor fuel quality
•  Mechanical (engine) malfunction
―  Large mechanical resistance
―  Low engine compression
―  Improper valve timing
―  Engine oil malfunction (oil working up or down)

Diagnostic procedure

Step

Inspection

Results

Action

1
DETERMINE IF MALFUNCTION CAUSED BY A/C SYSTEM OPERATION
•  Verify the A/C system operation.
•  Is the A/C system operation normal?
Yes
Go to the next step.
No
Perform the symptom troubleshooting “A/C DOES NOT WORK SUFFICIENTLY” and “A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY”.
2
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.
No
Go to the next step.
3
VERIFY DTC
•  Perform the DTC inspection for the following modules.
―  PCM
―  TCM
―  DSC HU/CM
―  SAS control module
•  Are any DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
No
Go to the next step.
4
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.
•  If the CAN communication is normal, repeat the inspection from Step 1.
―  If the malfunction recurs, perform the following procedure.
•  Replace the DSC HU/CM. (Brake fluid pressure sensor (built-into DSC HU/CM) or DSC HU/CM brake pressure hold function malfunction.)
―  Perform the repair completion verification 1.
No
Go to the next step.
5
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.
6
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.
7
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.
8
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.
9
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.
10
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.
11
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.
12
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.
13
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.
•  If the CAN communication is normal, perform the diagnosis from Step 1.
―  If the malfunction recurs, replace the electric AT oil pump and perform the repair completion verification 1.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
14
INSPECT RELATED PART CONDITION
•  Inspect the following:
―  Lack of ATF
―  Brake dragging
•  Are all items normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
15
INSPECT DRIVE BELT 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.
16
INSPECT FOR FUEL LEAKAGE FROM FUEL SYSTEM
•  Visually inspect the following:
―  Fuel leakage from the fuel tank, fuel pump, hose, pipe, fuel injector, supply pump, common rail
―  Cracking and damage in fuel hose and pipe
―  Clamp installation condition for each hose and pipe
―  Fuel pipe securing condition due to deterioration such as rubber of clamp
•  Are all items normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
17
INSPECT FUEL INJECTION SYSTEM RELATED PARTS
•  Inspect the following parts:
―  Common rail
―  Supply pump
―  Suction control valve
―  Fuel injector
―  Fuel pressure relief valve
―  Fuel filter
•  Are all items normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning location and perform the repair completion verification 1.
18
INSPECT FOR MALFUNCTION DUE TO POOR FUEL
•  Replace the fuel.
•  Does the symptom disappear?
Yes
Advise the customer as to the change in the fuel used.
No
Remove the accumulated matter in the cylinder head using the following procedure, then go to the next step.
•  Carbon remover
•  Overhauling
19
DETERMINE IF MALFUNCTION IS DUE TO EXCESSIVE ENGINE SPEED RESISTANCE
•  Rotate the crankshaft pulley lock bolt clockwise using a wrench.
•  Can the bolt be rotated?
Yes
Go to Step 21.
No
Go to the next step.
20
INSPECT FOR MALFUNCTION DUE TO EXCESSIVE MECHANICAL RESISTANCE OF ENGINE ACCESSORIES
•  Remove all drive belts from engine accessories.
Caution
•  Do not run the engine with the drive belts of engine accessories removed. Otherwise the engine could be damaged from overheating.
•  Start the engine.
•  Is cranking possible? (Does engine start?)
Yes
Mechanical resistance in engine accessories.
•  Repair or replace the malfunctioning location and perform the repair completion verification 1.
No
Go to the next step.
21
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression.
•  Are compression pressures within specification?
Yes
Perform the repair completion verification 1.
No
Go to the next step.
22
INSPECT FOR MALFUNCTION DUE TO DEVIATED VALVE TIMING
•  Inspect the valve timing (timing chain installation condition).
•  Is the valve timing normal?
Yes
Go to the next step.
No
Adjust the valve timing to the correct timing and perform the repair completion verification 1.
23
INSPECT FOR MALFUNCTION DUE TO INTERNAL ENGINE WEAR, DAMAGE
•  Inspect for the following engine internal parts:
―  Cylinder
―  Piston ring
―  Intake valve
―  Exhaust valve
―  Such as cylinder head gasket
•  Are all items normal?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
•  If the CAN communication is normal, perform the diagnosis from Step 1.
―  If the malfunction recurs, replace the lower case, then perform the repair completion verification 1. (Fuel may not inject normally.)
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.
•  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.