NO.15 EMISSION COMPLIANCE [WITHOUT WU-TWC]

id0103008021c6

15

EMISSION COMPLIANCE

DESCRIPTION

Fails the emissions test.

POSSIBLE CAUSE

• Vacuum lines leakage or blockage
• Cooling system malfunction
• Spark plug malfunction
• Leakage from intake manifold
• Erratic or no signal from CMP sensor
• Inadequate fuel pressure
• PCV valve malfunction or incorrect valve installation
• Exhaust system clogging
• Fuel tank ventilation system malfunction
• Charcoal canister damage
• Air cleaner element clogging or restriction
• Throttle body malfunction
• Spark leakage from high-tension leads
• Improper air/fuel mixture ratio control operation
• Catalytic converter malfunction
• Engine internal parts malfunction
• Excessive carbon is built up in combustion chamber
• Improper engine compression
• Improper valve timing
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 injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual.
(See BEFORE REPAIR PROCEDURE.)
(See AFTER REPAIR PROCEDURE.)
Caution
• If there is foreign material on the connecting area of the quick release connector, it might damage the connector or fuel pipe. To prevent this, disconnect the connector and clean the connecting area before connecting.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Inspect the following:
• Vacuum lines for leakage or blockage
• Electrical connections
• Proper maintenance schedule followed
• Intake-air system and air cleaner element concerns: obstructions, leakage, or dirt
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 1.
2
Connect the WDS or equivalent to the DLC-2.
Retrieve any continuous memory, KOEO and KOER DTCs.
Are there any DTCs displayed?
Yes

DTC is displayed:

Go to the appropriate DTC test.
No

No DTC is displayed:

Go to the next step.
3
Is any other driveability concern present?
Yes
Go to the appropriate symptom troubleshooting.
No
Go to the next step.
4
Connect the WDS or equivalent to the DLC-2.
Access the ECT PID.
Warm up the engine and idle it.
Verify that the ECT PID is correct.
Is the ECT PID correct?
Yes
Go to the next step.
No
Inspect for coolant leakage, cooling fan and condenser fan operation, or thermostat operation.
5
Carry out a spark test.
(See Spark Test.)
Is a strong blue spark visible at each cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to spark test results.
6
Install a fuel pressure gauge between fuel pipe and fuel distributor.
Start the engine and idle it.
Measure the fuel line pressure at idle.
Is the fuel line pressure correct at idle?
Yes
Go to the next step.
No

Zero or low:

Inspect the fuel pump relay and fuel pump related circuits.
Inspect for fuel leakage inside pressure regulator.
Inspect for a clogged main fuel line.

High:

Inspect the pressure regulator cause for high pressure.
Inspect for clogged fuel return line.
Inspect the vacuum hose to the pressure regulator.
7
Remove and shake the PCV valve.
Does the PCV valve rattle?
Yes
Go to the next step.
No
Replace the PCV valve.
8
Inspect for fuel saturation inside the charcoal canister.
Is an excess amount of liquid fuel present in the canister?
Yes
Replace the charcoal canister.
No
Inspect fuel tank vent system.
Then, go to the next step.
9
Are there restrictions in the exhaust system?
Yes
Inspect the exhaust system.
No
Inspect the three way catalytic converter.
10
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If malfunction remains, replace or reprogram the PCM.