NO.14 POOR FUEL ECONOMY [SKYACTIV-G 2.5T]

id0103q4802000

14

POOR FUEL ECONOMY

DESCRIPTION

•  The fuel consumption is high compared to the customer’s expectations or the previous fuel consumption.

POSSIBLE CAUSE

Note

•  The perceived poor fuel economy condition has two causes; the vehicle conditions and how the driver uses the vehicle. Especially, it relies heavily on how the driver uses the vehicle.

•  Use of inferior fuel

―  Ethanol blended

―  Lower octane

•  Engine oil malfunction

―  Improper engine oil level

―  Engine oil contamination

―  Improper engine oil viscosity

•  Improper engine compression

•  Ignition system malfunction

•  Improper engine coolant level

•  Improper tire air pressure

•  Improper tires, wheels (large size, irregular size)

•  Improper wheel alignment

•  Improper ATF level

•  Brake dragging

•  Engine operation time is longer than traveled distance

―  Vehicle is driven in congested traffic frequently

―  Vehicle left idling for long periods

•  Amount of fuel injection increases

―  Vehicle is carrying excess items (luggage)

―  Frequent acceleration/deceleration

―  Frequently driving uphill

―  Travel distances are short (engine does not warm up)

14	POOR FUEL ECONOMY
DESCRIPTION	• The fuel consumption is high compared to the customer’s expectations or the previous fuel consumption.
POSSIBLE CAUSE	Note • The perceived poor fuel economy condition has two causes; the vehicle conditions and how the driver uses the vehicle. Especially, it relies heavily on how the driver uses the vehicle. • Use of inferior fuel ― Ethanol blended ― Lower octane • Engine oil malfunction ― Improper engine oil level ― Engine oil contamination ― Improper engine oil viscosity • Improper engine compression • Ignition system malfunction • Improper engine coolant level • Improper tire air pressure • Improper tires, wheels (large size, irregular size) • Improper wheel alignment • Improper ATF level • Brake dragging • Engine operation time is longer than traveled distance ― Vehicle is driven in congested traffic frequently ― Vehicle left idling for long periods • Amount of fuel injection increases ― Vehicle is carrying excess items (luggage) ― Frequent acceleration/deceleration ― Frequently driving uphill ― Travel distances are short (engine does not warm up)

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY ALL SYSTEM DTCs Note • Display the DTCs of all the modules using the M-MDS. • Connect the M-MDS to the DLC-2. • After the vehicle is identified, select the following items from the initialization screen of the M-MDS. 1. Select “Self Test”. 2. Select "All CMDTCs". • Verify the DTC according to the directions on the screen. • Are any DTCs present?	Yes	Go to the applicable DTC inspection.
1		No	Go to the next step.
2	VERIFY IF MALFUNCTION SYMPTOM IS CAUSED BY OTHER MALFUNCTION Note • There are few malfunction affecting only the fuel economy, therefore it is necessary to verify that other malfunctions are not appearing as symptoms. • Verify the vehicle engine condition. • Can malfunction symptoms other than “NO.14 POOR FUEL ECONOMY” be verified?	Yes	Go to the applicable symptom troubleshooting. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5T].)
2		No	Go to the next step.
3	INSPECT ENGINE AND VEHICLE CONDITIONS Note • Because the vehicle malfunction cannot be verified, it is necessary to inspect the items which may be adversely affecting fuel consumption. • Perform the following inspections: ― Use of inferior fuel ― Engine oil level (See ENGINE OIL LEVEL INSPECTION [SKYACTIV-G 2.5T].) ― Engine oil contamination ― Engine coolant level (See ENGINE COOLANT LEVEL INSPECTION [SKYACTIV-G 2.5T].) ― Engine compression pressure inspection (See COMPRESSION INSPECTION [SKYACTIV-G 2.5T].) ― Spark Test (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.5T].) ― Tire air pressure ― Wheel alignment (See SUSPENSION TECHNICAL DATA.) ― Improper ATF level (See AUTOMATIC TRANSAXLE FLUID (ATF) ADJUSTMENT [GW6A-EL, GW6AX-EL].) ― Brake dragging • Is there any malfunction?	Yes	Repair or adjust the malfunctioning location and explain the repair contents to the customer based on the inspection result.
3		No	Go to the next step.
4	VERIFY VEHICLE USE CONDITION Note • It is necessary to ask the customer about how they use the vehicle because there is no problem with the inspection items from Step 1 to 3. • Verify how the customer uses the vehicle with regard to the following applicable items, and provide the customer some pertinent advice: ― Tires, wheels (large size) ― Engine operation time is longer than traveled distance • Vehicle is driven in congested traffic frequently • Vehicle left idling for long periods ― Amount of fuel injection increases • Vehicle is carrying excess items (luggage) • Frequent acceleration/deceleration • Frequently driving uphill • Travel distances are short (engine does not warm up) • Driving frequently at high-altitude • Driving frequently during strong winds ― Use of unrecommended engine oil (leads to inappropriate oil viscosity)	—	Symptom troubleshooting is completed.