Before using this section, perform the ’’On-Board Diagnostic (OBD) System Check’’ and verify all of the following items:
• The ECM and CHECK ENGINE Lamp (MIL) are operating correctly.
• There are no DTCs stored.
• Tech 2 data is within normal operating range. • Verify the customer complaint and locate the
correct symptom in the table of contents. Perform the procedure included in the symptom diagnosis chart.
• Ask the customer if the specified engine oil and fuel are used.
Visual/Physical Check
Several of the symptom procedures call for a careful visual/physical check. This can lead to correcting a problem without further checks and can save valuable time.
This check should include the following items: • Check the engine oil for level.
• Check the oil filter for loose installation. • Check the oil pan for loose installation.
• Check the oil pipe for crack or loose connection. • Check the PCV hose for crack or loose connection.
Intermittents IMPORTANT:
An intermittent problem may or may not turn on the CHECK ENGINE Lamp (MIL) or store a DTC. Do not use the Diagnostic Trouble Code (DTC) charts for intermittent problems. The fault must be present to locate the problems.
Most intermittent problems are caused by faulty electrical connections or wiring. Perform a careful visual/physical check for the following conditions:
• Poor mating of the connector halves of a pin not fully seated in the connector (backed out). • Improperly formed or damaged pin.
• All connector pin in the problem circuit should be carefully checked for proper contact tension.
• Poor pin-to-wire connection. This requires removing the pin from the connector body to check.
Road test the vehicle with a Digital Multimeter (5- 8840-0366-0) connected to a suspected circuit. In case of a malfunction, abnormal voltage indicates the presence of a fault in the circuit being checked. Use a scan tool to help detect intermittent Use a scan tool to help detect intermittent conditions. The scan tools have several features that can be used to locate an intermittent condition. Use the following feature for find intermittent faults:
The check for loss of DTC memory, disconnect the intake air pressure sensor and idle the engine until the CHECK ENGINE Lamp (MIL) comes on. DTC32 should be stored and kept in memory when the starter switch is turned “OFF”. If not, the ECM is faulty. When this test is completed, make sure that you clear the DTC32 from memory.
A CHECK ENGINE Lamp (MIL) with no stored DTC may be caused by the following:
• CHECK ENGINE Lamp (MIL) wire to ECM shorted to ground.
• Poor ECM grounds.
Check for improper installation of electrical options such as lights, cellular phones, etc.
If DTC is not confirmed, snap-shot the Tech 2 data list, so that approximate faulty location can be estimated according to the follow-up performance or validity of numeric values, or identification of fixed values.
1. If a systematic error is recognized in numeric values, fundamental accuracy of instruments such as sensors will be faulty (for example, variations in sensor resistance value).
2. If a random error is recognized in numeric values, in general it will be caused by electrical (applied voltage) or mechanical troubles or noise.
3. If numeric values are fixed to high or low (fixed value error), the open wiring or short will occur in the circuits of instruments such as sensors.
Step Action Value(s) Yes No
1
DEFINITION:
The engine oil consumption measured in actual road test is excessively larger than expectation.
Was the "On-Board diagnostic(OBD) System Check" performed?
—
Go to Step 2
Go to “OBD System Check”
2 Was a visual/physical check performed? —
Go to Step 3
Go to Visual/ Physical Check
3
1. Observe if proper engine oil is used.
2. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair Go to Step 4
4
1. Observe if the engine oil level is too high. 2. If high, lower the level.
Is the oil level proper?
—
Go to Step 5 Verify repair
5
1. Check the oil leak for oil pipe connection portions.
2. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair Go to Step 6
6
1. Check if oil leaks from oil seals or
gaskets.
2. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair Go to Step 7
7
1. Check the PCV (Positive Crankcase
Ventilation) valve for any problem, restriction, or improper installation. Also, check the PCV system for restriction.
2. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair Go to Step 8
8
1. Check the valve stem and valve guide for wear.
2. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair Go to Step 9
9
1. Check the piston rings for wear, stick,
chipping, and also check the ring grooves for wear.
2. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair Go to Step 10
10
1. 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 check • Tech 2 data.
• All electrical connections within a suspected circuit and/or system.
3. If a problem is detected, repair as
necessary.
Was a problem detected?
—
Verify repair —