NO.15 EMISSION COMPLIANCE [L8, LF]

id0103a0802100

15

EMISSION COMPLIANCE
DESCRIPTION
•  Fails emissions test.
POSSIBLE CAUSE
•  Disconnected electrical connectors
•  Intake-air system and air cleaner element clogging or restriction
•  Vacuum lines leakage or blockage
•  Cooling system malfunction
•  A/F sensor malfunction
―  Exhaust gas leakage between exhaust manifold and A/F sensor
―  Loose installation of A/F sensor
―  A/F sensor malfunction
•  Spark plug malfunction
•  Inadequate fuel pressure
•  Charcoal canister malfunction
•  Fuel tank ventilation system malfunction
•  Exhaust system clogging
•  TWC malfunction
•  Improper operation of EGR control system
•  PCV valve malfunction
•  PCM malfunction
Warning
The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read following warnings before performing 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 “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual.
Caution
•  Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean 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 the following:
•  Electrical connections
•  Intake-air system and air cleaner element concerns: obstructions, leakage or dirtiness
•  Proper maintenance schedule followed
•  Vacuum lines for leakage or blockage
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 1.
No
Go to the next step.
2
Connect the M-MDS to the DLC-2.
Perform the KOEO/KOER self test and the DTC Reading Procedure.
(See KOEO/KOER SELF TEST [L8, LF].)
(See ON-BOARD DIAGNOSTIC TEST [L8, LF].)
Are any DTCs present?
Yes
Go to the appropriate DTC inspection.
(See DTC TABLE [L8, LF].)
No
Go to the next step.
3
Is any other driveability concern present?
Yes
Go to the appropriate symptom troubleshooting.
(See QUICK DIAGNOSTIC CHART [L8, LF].)
No
Go to the next step.
4
Connect the M-MDS to the DLC-2.
Perform the PID/DATA Monitor and Record Procedure.
(See ON-BOARD DIAGNOSTIC TEST [L8, LF].)
Access and record the ECT PID while warm up the engine from it is cold.
Note
•  ECT PID increase incline speed is slowly while engine coolant temperature approx. 80 °C {176 °F} because of thermostat begins to open. (The ECT PID climb gradient is moderated because the thermostat starts to open when the engine coolant temperature is 80 °C {176 °F} or more.)
Does the ECT PID increase incline become properly?
Yes
Go to the next step.
No
Inspect the coolant leakage, cooling fan and thermostat operation.
Repair or replace the malfunctioning part according to the inspection results.
5
Inspect the A/F sensor.
(See AIR FUEL RATIO (A/F) SENSOR INSPECTION [L8, LF].)
Is there any malfunction?
Yes
Inspect the followings:
•  Exhaust gas leakage between exhaust manifold and A/F sensor
•  Loose installation of A/F sensor
If there is no malfunction:
•  Replace the A/F sensor.
If there is a malfunction:
•  Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
6
Perform the Spark Test.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L8, LF].)
Is the strong blue spark visible at each cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
7
Install fuel pressure gauge between the fuel pipe and the fuel distributor.
Start the engine and idle it.
Measure the fuel line pressure during idle.
(See FUEL LINE PRESSURE INSPECTION [L8, LF].)
Is fuel line pressure correct during idle?
Yes
Go to the next step.
No
Zero or low:
•  Inspect the fuel pump and fuel pump relay related circuit.
•  Inspect for clogged fuel line.
•  If there is no malfunction:
―  Replace the fuel pump unit.
•  If there is a malfunction:
―  Repair or replace the malfunctioning part according to the inspection results.
High:
•  Replace the fuel pump unit.
8
Inspect for fuel saturation inside the charcoal canister.
Is the excess amount of liquid fuel present in canister?
Yes
Replace the charcoal canister.
(See CHARCOAL CANISTER REMOVAL/INSTALLATION [L8, LF].)
No
Inspect the fuel tank vent system.
(See FUEL TANK INSPECTION [L8, LF].)
Repair or replace the malfunctioning part according to the inspection results.
9
Visually inspect the exhaust system part.
Is there any deformed exhaust system part?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
10
Inspect the TWC.
(See EXHAUST SYSTEM INSPECTION [L8, LF].)
Is there any malfunction?
Yes
Replace the TWC.
(See EXHAUST SYSTEM REMOVAL/INSTALLATION [L8, LF].)
No
Go to the next step.
11
Perform the EGR Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L8, LF].)
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Replace the PCV valve.
12
Verify test results.
•  If normal, return to diagnostic index to service any additional symptoms.
•  If malfunction remains, inspect related Service information perform repair or diagnosis.
―  If vehicle repaired, troubleshooting completed.
―  If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF].)