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Home >> Mazda >> 2021 >> CX-3 FWD >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine >> No. 14 Poor Fuel Economy >> Diagnostic Procedure

Diagnostic Procedure

NO. 14 POOR FUEL ECONOMY 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.
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 .)
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.
  • Is there any malfunction?
Yes Repair or adjust the malfunctioning location and explain the repair contents to the customer based on the inspection result.
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.