TROUBLESHOOTING
F1–57
F1
ENGINE SYMPTOM TROUBLESHOOTINGA6E398018881201•Confirm trouble symptom using the following diagnostic index, then go to appropriate troubleshooting chart.
Diagnostic Index
End Of Sie
TROUBLESHOOTING
No. TROUBLESHOOTING ITEM DESCRIPTION
1 Melting of main or other fuses—
2 MIL illuminates MIL is illuminated incorrectly.
3 Will not crank Starter does not work.
4Hard to start/long crank/erratic start/erratic
crankStarter cranks engine at normal speed but engine requires excessive
cranking time before starting.
5 Engine stalls. After start/at idle Engine stops unexpectedly at idle and/or after start.
6 Cranks normally but will not start Starter cranks engine at normal speed but engine will not run.
7 Slow return to idle Engine takes more time than normal to return to idle speed.
8 Engine runs rough/rolling idleEngine speed fluctuates between specified idle speed and lower
speed and engine shakes excessively.
9 Fast idle/runs onEngine speed continues at fast idle after warm-up.
Engine runs after ignition switch is turned to off.
10 Low idle/stalls during decelerationEngine stops unexpectedly at beginning of deceleration or recovery
from deceleration.
11Engine stalls/quits. Acceleration/cruiseEngine stops unexpectedly at beginning of acceleration or during
acceleration.
Engine stops unexpectedly while cruising.
Engine runs rough. Acceleration/cruise Engine speed fluctuates during acceleration or cruising.
Misses Acceleration/cruise Engine misses during acceleration or cruising.
Buck/jerkAcceleration/cruise/
decelerationVehicle bucks/jerks during acceleration, cruising, or deceleration.
Hesitation/stumble Acceleration Momentary pause at beginning of acceleration or during acceleration
Surges Acceleration/cruise Momentary minor irregularity in engine output
12 Lack/loss of power Acceleration/cruisePerformance is poor under load.
(e.g., power down when climbing hills)
13 Knocking/pinging Acceleration/cruiseSound is produced when air/fuel mixture is ignited by something other
than spark plug. (e.g., hot spot in combustion chamber)
14 Poor fuel economy Fuel economy is unsatisfactory.
15 Emission compliance Fails emissions test.
16 High oil consumption/leakage Oil consumption is excessive.
17Cooling system
concernsOverheating Engine runs at higher than normal temperature/overheats.
18Cooling system
concernsRuns cold Engine does not reach normal operating temperature.
19 Exhaust smoke Blue, black, or white smoke from exhaust system
20 Fuel odor (in engine compartment) Gasoline fuel smell or visible leakage
21 Engine noise Engine noise from under hood
22 Vibration concerns (engine) Vibration from under hood or driveline
23 A/C does not work sufficiently.A/C compressor magnetic clutch does not engage when A/C is turned
on.
24A/C is always on or A/C compressor runs
continuously.A/C compressor magnetic clutch does not disengage.
25 A/C is not cut off under WOT conditions. A/C compressor magnetic clutch does not disengage under WOT.
26 Exhaust sulphur smell Rotten egg smell (sulphur) from exhaust
27 Constant voltage Incorrect constant voltage
28 Spark plug condition Incorrect spark plug condition
29 ATX concernsUpshift/downshift/
engagementATX concerns not related to engine performance
TROUBLESHOOTING
F1–63
F1
End Of Sie
4 Is strong blue spark visible at each disconnected
high-tension lead while cranking engine?Yes Inspect for following:
•Spark plugs malfunction
•CMP sensor is improperly installed.
•Trigger wheel damage on camshaft
•Open or short circuit on CMP sensor
•Open or short circuit between CMP sensor and
PCM terminal 2J or 2M
Repair or replace malfunctioning parts.
If okay, go to next step.
No Inspect following:
•High-tension leads
•Ignition coil and connector
5 Install fuel pressure gauge between fuel pipe
and fuel distributor.
Start engine and run it at idle.
Measure fuel line pressure at idle.
Is fuel line pressure correct at idle?Yes Go to next step.
NoZero or low:
Inspect for clogged fuel line.
If okay, replace fuel pump unit
High:
Replace fuel pump unit.
6 Inspect for VTCS operation.
Does VTCS work properly?Yes Go to next step.
No Repair or replace malfunctioning parts.
7Note
•The following test should be performed for
vehicles with variable valve timing control
system. Go to next step for vehicles
without variable valve timing control
system.
Inspect for variable valve timing control system
operation.
Does variable valve timing control system work
properly?Yes Go to next step.
No Repair or replace malfunctioning parts.
8Note
•The following test should be performed for
vehicles with VIS. Go to next step for
vehicles without VIS.
Inspect for VIS operation.
Does VIS work properly?Yes Go to next step.
No Repair or replace malfunctioning parts.
9 Remove and shake PCV valve.
Does PCV valve rattle?Yes Go to next step.
No Replace PCV valve.
10 Inspect for restriction in the exhaust system.
Is there any restriction?Yes Inspect exhaust system.
No Go to next step.
11 Inspect for contaminated MAF sensor.
Is there any contamination?Yes Go to next step.
No Inspect for cause.
12 Inspect MAF sensor for contamination.
Is there any contamination?Yes Replace MAF sensor.
No Go to Step 14. (2WD)
Go to next step. (4WD)
13 Inspect electrically controlled 4WD system
operation.
Is operation of electrically controlled 4WD
system okay?Yes Go to next step.
No Repair or replace malfunctioning parts.
14 Is engine compression correct? Yes Inspect valve timing.
No Inspect for cause.
15 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. STEP INSPECTION RESULTS ACTION
