Diagnostic Procedure

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POOR FUEL ECONOMY (VIN Y) DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	VERIFY ALL SYSTEM DTCs Perform the quick check using the M-MDS. (See DTC INSPECTION .) Are any DTCs displayed?	Yes	Repair or replace the malfunctioning location according to the applicable DTC troubleshooting.
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 [POOR FUEL ECONOMY] be verified? (See SYMPTOM TROUBLESHOOTING (VIN Y) .)	Yes	Perform symptom troubleshooting following the applicable symptom troubleshooting procedure. (See SYMPTOM TROUBLESHOOTING (VIN Y) .)
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. Engine oil level (Refer to ENGINE OIL LEVEL INSPECTION (VIN Y) .) Engine oil contamination Engine coolant level (Refer to ENGINE COOLANT LEVEL INSPECTION (VIN Y) .) Engine compression pressure inspection (Refer to COMPRESSION INSPECTION (VIN Y) .) Spark Test (Refer to SPARK INSPECTION (VIN Y) .) Tire air pressure Improper ATF level (Refer to AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION [EV6AX-EL] and/or AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION [GW6AX-EL] .) Brake dragging EGR system (Refer to EGR VALVE INSPECTION (VIN Y) .) 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 the use conditions for the following items. Installation of tire, wheel other than specified size (oversized) 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) Use of unrecommended engine oil (leads to inappropriate oil viscosity) Are there any applicable items?	Yes	Provide pertinent advice for the applicable items.
4		No	Complete the symptom troubleshooting. (Explain contents of repair to customer)