Dtc Check

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MAKE A NOTE OF DTCS DISPLAYED AND THEN CLEAR MEMORY

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SYMPTOM CONFIRMATION

Result

Result

Proceed to

No symptoms exist

A

Symptoms exist

4

SIMULATION TEST USING SYMPTOM SIMULATION METHODS

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5

Go to step 5

Result

Proceed to

DTC is not output

A

DTC is output

B

TROUBLESHOOTING OF PROBLEM INDICATED BY DTC

SYMPTOM CONFIRMATION

Result

Result

Proceed to

Symptoms exist

A

No symptoms exist

B

If a DTC was displayed in the initial DTC check, the problem may have occurred in a wire harness or connector in that circuit in the past. Check the wire harness and connectors.

SYSTEM NORMAL

TROUBLESHOOTING OF EACH PROBLEM SYMPTOM

The problem is still occurring in a place other than the diagnostic circuit (the DTC displayed first is either for a past problem or a secondary problem). 4. SYMPTOM SIMULATION HINT:

The most difficult case in troubleshooting is when no problem symptoms occur. In such a case, a thorough problem analysis must be carried out. A simulation of the same or similar conditions and environment in which the problem occurred in the customer's vehicle should be carried out. No matter how much skill or experience a technician has, troubleshooting without confirming the problem symptoms will lead to important repairs being overlooked and mistakes or delays. For example: With a problem that only occurs when the engine is cold or as a result of vibration caused by the road during driving, the problem can never be determined if the symptoms are being checked on a stationary vehicle or on a vehicle with a warmed-up engine. Vibration, heat or water penetration (moisture) is difficult to reproduce. The symptom simulation tests below are effective substitutes for the conditions and can be applied on a stationary vehicle. Important points in the symptom simulation test:

In the symptom simulation test, the problem symptoms as well as the problem area or parts must be confirmed. First, narrow down the possible problem circuits according to the symptoms. Then, connect the tester and carry out the symptom simulation test, judging whether the circuit being tested is defective or normal. Also, confirm the problem symptoms at the same time. Refer to the problem symptoms table for each system to narrow down the possible causes.

(a) VIBRATION METHOD:

When a malfunction seems to occur as a result of vibration.

(1) PART AND SENSOR

Apply slight vibration with a finger to the part of the sensor suspected to be the cause of the problem, and check whether or not the malfunction occurs. NOTICE:

Applying strong vibration to relays may open them.

(2) CONNECTORS

Slightly shake the connector vertically and horizontally.

(3) WIRE HARNESS

Slightly shake the wire harness vertically and horizontally.

HINT:

The connector joint and fulcrum of the vibration are the major areas that should be checked thoroughly.

When a malfunction seems to occur when the area in question is heated.

(1) Heat the component that is the possible cause of the malfunction with a hair dryer or similar device. Check if the malfunction occurs. NOTICE:

• Do not heat to more than 60°C (140°F). Exceeding this temperature may damage components.

• Do not apply heat directly to the parts in the ECU.

(c) WATER SPRINKLING METHOD:

When a malfunction seems to occur on a rainy day or in high-humidity.

(1) Sprinkle water onto the vehicle and check if the malfunction occurs. NOTICE:

• Never sprinkle water directly into the engine compartment. Indirectly change the temperature and humidity by spraying water onto the front of the radiator.

• Never apply water directly onto the electronic components.

HINT:

If the vehicle has or had a water leakage problem, the leakage may have damaged the ECU or connections. Look for evidence of corrosion or short circuits. Proceed with caution during water tests.

(d) HIGH ELECTRICAL LOAD METHOD:

When a malfunction seems to occur when electrical load is excessive.

(1) Turn on the heater blower, headlight, rear window defogger and all other electrical loads. Check if the malfunction reoccurs. 5. DIAGNOSTIC TROUBLE CODE CHART Look for output Diagnostic Trouble Codes (DTCs) (from the DTC checks) in the appropriate section's Diagnostic Trouble Code Chart. Use the chart to determine the trouble area and the proper inspection procedure. A description of each of the chart's columns are below.

Item

Description

DTC No.

Indicates the diagnostic trouble code

Detection Item

Indicates the system or details of the problem

Trouble Area

Indicates the suspect areas of the problem

See Page

Indicates the page where the inspection procedures for each circuit is to be found, or gives instruction for checking and repairs.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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