NO.14 POOR FUEL ECONOMY [MZR 2.3 DISI Turbo]

id0103e2802000

14

POOR FUEL ECONOMY
DESCRIPTION
•  Fuel economy is unsatisfactory.
POSSIBLE CAUSE
•  Contaminated air cleaner element
•  Engine cooling system malfunction
•  Weak spark
•  Spark plug malfunction
•  Poor fuel quality
•  Erratic signal from CKP sensor
•  Erratic or no signal from CMP sensor
•  Fuel pressure sensor (built-in fuel delivery pipe) malfunction
•  ECT sensor or related circuit malfunction
•  MAP sensor (integrated in MAP sensor/boost air temperature sensor) or related circuit malfunction
•  APP sensor or related circuit malfunction
•  MAF sensor (integrated in MAF/IAT sensor) or related circuit malfunction
•  Contaminated MAF sensor
•  IAT sensor (integrated in MAF/IAT sensor) or related circuit malfunction
•  Boost air temperature sensor (integrated in MAP sensor/boost air temperature sensor) or related circuit malfunction
•  VSS or related circuit malfunction
•  CPP switch or related circuit malfunction
•  Neutral switch or related circuit malfunction
•  Variable swirl system malfunction
•  Improper coolant level
•  Inadequate fuel pressure (high-pressure side)
•  Injection timing is incorrect
•  Fuel injector or related circuit malfunction
•  High pressure fuel pump malfunction
•  Fuel leakage
•  Fuel line restriction
•  Fuel filter clogging
•  PCV valve malfunction
•  Brake dragging
•  Clutch slippage
•  Improper operation of A/C system
•  Improper valve timing due to jumping out of timing chain
•  Improper engine compression
•  Turbocharger malfunction
•  Charge air cooler malfunction
•  Exhaust system and/or TWC clogging
•  EGR system malfunction
•  Vacuum leakage
Warning
•  The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
―  Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
―  Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual. (See BEFORE SERVICE PRECAUTION [MZR 2.3 DISI Turbo].) (See AFTER SERVICE PRECAUTION [MZR 2.3 DISI Turbo].)
Caution
•  Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Inspect for the following:
•  Air cleaner element for contamination
•  Intake-air system restriction
•  Fuel quality (proper octane, contamination, winter/summer blend)
•  Coolant level
•  Clutch slippage
•  Brake dragging
•  Charge air cooler condition (restriction or damaged)
•  Vacuum leakage
•  Fuel leakage
•  MAF sensor contaminated
•  Exhaust system and/or TWC restriction
Is there any malfunction?
Yes
Service if necessary.
•  Repeat this step.
No
Go to the next step.
2
Switch the ignition to ON.
Retrieve any DTCs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 2.3 DISI Turbo].)
No
Go to the next step.
3
Perform the Cooling Fan Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Does the cooling fan system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
4
Perform the EGR Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Does the EGR system operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
5
Perform the Variable Swirl System Operation Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Does the variable swirl system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
6
Perform the Wastegate Control System Operation Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Does the wastegate control system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
7
Perform the A/C Cut-off Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Does the A/C cut-off operation work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
8
Perform the Spark Test.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Is a strong blue spark visible at each cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
9
Inspect the CMP sensor and CKP sensor for the following:
•  Installation condition
•  Damaged trigger wheel and camshaft
•  Open or short circuit in the wiring harnesses
Is there any malfunction?
Yes
Repair or replace the malfunctioning parts according to the inspection results.
No
Go to the next step.
10
Access the following PIDs using the M-MDS:
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)
•  APP1
•  APP2
•  BAT
•  ECT
•  MAF
•  CPP
•  CPP/PNP
•  IAT
•  TP REL
•  MAP
•  VSS
Do the PID values indicate the correct values under the trouble condition?
(See PCM INSPECTION [MZR 2.3 DISI Turbo].)
Yes
Go to the next step.
No
Inspect the suspected parts and related wiring harness.
•  If normal:
―  Perform the “INTERMITTENT CONCERN TROUBLESHOOTING.
•  If not:
―  Repair or replace the malfunctioning parts according to the inspection results.
11
Access the FUEL_PRES PID using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)
Is the FUEL_PRES PID value within the specification?
(See PCM INSPECTION [MZR 2.3 DISI Turbo].)
Yes
Go to Step 15.
No
Go to the next step.
12
Is the vehicle accelerate performance normally?
Yes
Go to the next step.
No
Go to Step 14.
13
Inspect the fuel pressure sensor.
(See FUEL PRESSURE SENSOR INSPECTION [MZR 2.3 DISI Turbo].)
Is there any malfunction?
Yes
Replace the fuel delivery pipe.
(See FUEL INJECTOR REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
No
Go to Step 15.
14
Replace the high pressure fuel pump.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
Access the FUEL_PRES PID using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].)
Is the FUEL_PRES PID value within the specified?
(See PCM INSPECTION [MZR 2.3 DISI Turbo].)
Yes
High-pressure fuel pump or spill valve control solenoid valve (built-in high pressure fuel pump) malfunction.
•  Go to Step 19.
No
Relief valve or fuel pressure sensor malfunction.
•  Replace the fuel delivery pipe.
15
Inspect the turbocharger.
(See TURBOCHARGER INSPECTION [MZR 2.3 DISI Turbo].)
Is there any malfunction?
Yes
Replace the turbocharger.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
No
Go to the next step.
16
Perform the Fuel Injector Operation Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.3 DISI Turbo].)
Do the fuel injectors operate normally?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts according to the inspection results.
17
Measure the compression pressure for each cylinder.
(See COMPRESSION INSPECTION [MZR 2.3 DISI Turbo].)
Are compression pressures within the specification?
Yes
Go to the next step.
No
Inspect for the following:
•  Damaged valve seat
•  Worn valve stem and valve guide
•  Worn or stuck piston ring
•  Worn piston, piston ring or cylinder
•  Improper valve timing
Repair or replace the malfunctioning parts according to the inspection results.
18
Inspect the PCV valve.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.3 DISI Turbo].)
Is there any malfunction?
Yes
Replace the PCV valve.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
No
Replace the PCM (injector driver circuit malfunction).
(See PCM REMOVAL/INSTALLATION [MZR 2.3 DISI Turbo].)
•  If a malfunction remains:
―  Repair or replace the malfunctioning part according to the inspection results.
19
Verify test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.