TROUBLESHOOTING ITEM

Low maximum speed and poor acceleration

DESCRIPTION

• Vehicle acceleration is poor at start.

• Delayed acceleration when accelerator pedal is depressed while driving.

POSSIBLE CAUSE

• Engine control system malfunction

• Signal malfunction

• APP sensor malfunction

• CKP sensor malfunction

• MAF sensor malfunction

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

APP

%

Accelerator pedal position

• Accelerator pedal released: Approx. 0%

• Accelerator pedal depressed: Approx. 100%

MAF

g/Sec

Mass air flow

• Displays MAF

V

• Switch ignition ON (engine off) (MAF: 0.59 g/s {0.078 lb/min}): Approx. 0.72 V

• Idle (after warm up) (MAF: 2.17 g/s {0.287 lb/min}): Approx. 0.86 V

• Racing (engine speed is 2,000 rpm) (MAF: 4.73 g/s {0.626 lb/min}): Approx. 1.07 V

RPM

RPM

Engine speed

• Displays engine speed

STEP

INSPECTION

ACTION

1

• Perform the symptom troubleshooting “NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE”.

  (See NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [SKYACTIV-G 2.5].)

• Is there any malfunction?

Yes

Repair or replace any malfunctioning parts according to the inspection result.

No

Go to the next step.

2

• Inspect the value at the following PCM PIDs using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• APP (APP sensor)

• MAF (MAF sensor)

• RPM (CKP sensor)

• Is there any malfunction?

Yes

Repair or replace any malfunctioning parts according to the inspection result.

No

Explain to the customer that the vehicle is not malfunctioning and they should keep an eye on it.