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)

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.