Page 2073 of 6000
6E–180
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Surges and/or Chuggles Symptom
StepNo Ye s Va l u e ( s ) Action
101. Check the exhaust system for possible restriction:
Inspect the exhaust system for damaged or
collapsed pipes.
Inspect the muffler for heat distress or possible
internal failure.
Check for a possible plugged catalytic
converter by checking the exhaust system
back pressure. Refer to
Restricted Exhaust
System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11
111. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance
Page 2074 of 6000

6E–181 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Engine delivers less than expected power. Little or no
increase in speed when accelerator pedal is pushed
down part-way.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to Visual/
Physical
Check
41. Remove and check the air filter element for dirt or
restrictions. Refer to
Air Intake System in
On-Vehicle Service.
2. Replace the air filter element if necessary.
Was a repair required?
—Verify repairGo to Step 5
51. Check AP sensor system. Refer to AP sensor
diagnostic
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 6
61. Check for water-or alcohol-contaminated fuel.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
71. Using a Tech 2, Injector test.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
81. Check the ECM grounds for the cleanliness,
tightness and proper locations. Refer to the ECM
wiring diagrams in
Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Check the exhaust system for possible restriction:
Inspect the exhaust system for damaged or
collapsed pipes.
Inspect the muffler for heat distress or possible
internal failure.
Check for a possible plugged catalytic
converter by checking the exhaust system
back pressure. Refer to
Restricted Exhaust
System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10
101. Check the torque converter clutch (TCC) for proper
operation. Refer to
Transmission Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11
Page 2075 of 6000
6E–182
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom
StepNo Ye s Va l u e ( s ) Action
111. Check for an engine mechanical problem. Check
for low compression, incorrect or worn camshaft,
loose timing belt, etc. Refer to
Engine Mechanical.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance
Page 2076 of 6000

6E–183 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Engine runs unevenly at idle. If severe, the engine or
vehicle may shake. Engine idle speed may vary in
RPM. Either condition may be severe enough to stall
the engine.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Go to Step 6Go to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to Visual/
Physical
Check
41. Check the ECM grounds for cleanliness, tightness
and proper routing. Refer to the ECM wiring
diagrams in
Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 5
51. Check for incorrect idle speed. Ensure that the
following conditions are present:
The engine is fully warm.
The accessories are “OFF.”
2. Using a Tech 2, monitor the AP position.
Is the AP position within the specified values?
0%Go to Step 10Go to Step 9
61. Visually/physically inspect for the following
conditions:
Restricted air intake system. Check for a
possible collapsed air intake duct, restricted
air filter element, or foreign objects blocking
the air intake system.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
71. Injector Test
Operate the each injector by Tech 2 with the
ignition “ON” and check if the working noise
confirm.
2. If a problem is found, check the harness or replace
the injector.
Is the action complete?
—Verify repairGo to Step 8
81. Check the transmission range switch circuit. Use a
Tech 2 and be sure the Tech 2 indicates that the
vehicle is in drive with the gear selector in drive or
overdrive.
2. If a problem is found, diagnose and repair the
transmission range switch as necessary (Refer to
Automatic Transmission Diagnosis).
Was a problem found?
—Verify repairGo to Step 9
Page 2077 of 6000

6E–184
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom
StepNo Ye s Va l u e ( s ) Action
91. Check for the following engine mechanical items.
Refer to
Engine Mechanical for diagnosis
procedures:
Low compression
Sticking or leaking valves
Worn camshaft lobe(s)
Camshaft drive belt slipped or stripped
Incorrect valve timing
Valves clearance
Broken valve springs
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10
101. Check for faulty engine mounts. Refer to Engine
Mechanical
for inspection of mounts.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11
111. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance
Page 2078 of 6000

6E–185 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Fuel economy, as measured by an actual road test, is
noticeably lower than expected. Also, economy is
noticeably lower than it was on this vehicle at one time,
as previously shown by an actual road test. (Larger than
standard tires will cause odometer readings to be
incorrect, and that may cause fuel economy to appear
poor when it is actually normal.)
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to Visual/
Physical
Check
4Check owner’s driving habits.
Is the A/C “ON” full time (defroster mode “ON”)?
Are tires at the correct pressure?
Are excessively heavy loads being carried?
Is acceleration too much, too often?
Is engine oil correct?
Was a problem found?
—Go to Step 5Go to Step 6
5Review the items in Step 4 with the customer and
advise as necessary.
Is the action complete?
—System OK—
61. Visually/physically check: Vacuum hoses for splits,
kinks, and improper connections and routing as
shown on the “Vehicle Emission Control
Information” label.
2. If a problem is found, repair as necessary.
Was a repair required?
—Verify repairGo to Step 7
71. Remove and check the air filter element for dirt or for
restrictions. Refer to
Air Intake System.
2. Replace the air filter element if necessary.
Was a repair required?
—Verify repairGo to Step 8
81. Check for low engine coolant level. Refer to Engine
Cooling
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Check for an incorrect or faulty engine thermostat.
Refer to
Engine Cooling.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10
101. Check for low engine compression. Refer to Engine
Mechanical
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11
Page 2079 of 6000

6E–186
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom
StepNo Ye s Va l u e ( s ) Action
111. Check the TCC operation. Refer to Transmission
Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Check the exhaust system for possible restriction:
Inspect the exhaust system for damaged or
collapsed pipes.
Inspect the muffler for heat distress or possible
internal failure.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
13Check for proper calibration of the speedometer.
Does the speed indicated on the speedometer closely
match the vehicle speed displayed on the Tech 2?
—Go to Step 15Go to Step 14
14Diagnose and repair an inaccurate speedometer
condition as necessary. Refer to
Vehicle Speed
Sensor
in Electrical Diagnosis.
Was a problem found?
—Verify repair—
151. Check the air intake system and the crankcase for
air leaks. Refer to
Air Intake System and
Crankcase Ventilation System.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 16
161. Review all diagnostic procedures within this table.
2. When all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All connections within a suspected circuit
and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 17
17Perform the procedure in Injector Test.
Was the fuel pressure normal?
—
Contact
Te c h n i c a l
Assistance
Verify repair
Page 2080 of 6000

6E–187 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Excessive Exhaust Emissions or Odors Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Vehicle fails an emission test. Vehicle has excessive
“rotten egg” smell. (Excessive odors do not necessarily
indicate excessive emissions.)
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a thorough visual/physical check performed?
—Go to Step 4
Go to Visual/
Physical
Check
41. Check for vacuum leaks. Check vacuum lines,
intake manifold, throttle body, etc.
2. If a problem is found, repair as necessary.
Were any vacuum leaks located?
—Verify repairGo to Step 5
51. Check the fuel cap for proper installation.
2. Secure the fuel cap if necessary.
Was the fuel cap installed properly?
—Go to Step 6Verify repair
61. Injector Test
Operate the each injector by Tech 2 with the
ignition “ON” and check if the working noise
confirm.
2. If a problem is found, check the harness or replace
the injector.
Is the action complete?
—Verify repairGo to Step 7
71. Refer to Engine Cooling for cooling system
diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
81. Check for an engine mechanical problem.
Perform a cylinder compression check (Refer to
Engine Mechanical).
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records butter
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repair
Contact
Te c h n i c a l
Assistance