Service Points In Inspecting A Blown Fuse; Inspecting The Mfi System; On-Board Diagnostics - Hyundai Tiburon 2003 Workshop Manual

1. Ask the customer about the malfunction.
Ask what it feels like, what it sounds like, etc. Then ask about driving conditions,weather, frequency of occurrence, and
so on.
2. Determine the conditions from the customer's responses.
Typically, almost all intermittent malfunctions occur from conditions likevibration, temperature and/or moisture change,
poor connections. From thecustomer's replies, it should be deduced which condition exists.
3. Use the simulation test
In the cases of vibration or poor connections, use the simulation tests belowto attempt to duplicate the customer's
complaint. Determine the most likelycircuit(s) and perform the simulation tests on the connectors and parts ofthat circuit
(s). Be sure to use the inspection procedures provided for diagnostictrouble codes and trouble symptoms. For
temperature and/or moisture conditionsrelated intermittent malfunctions, using common sense, try to change the
conditionsof the suspected circuit components, then use the simulation tests below.
4. Verify that the intermittent malfunction is eliminated.
Repair the malfunctioning part and try to duplicate the condition(s) againto verify that the intermittent malfunction has
been eliminated.
• Shake the connector up-and-down, right-and-left.
• Shake the wiring harness up-and-down, right-and-left.
• Vibrate the part or sensor.

SERVICE POINTS IN INSPECTING A BLOWN FUSE

• Harness being crushed by the vehicle body.
• Damage to the outer casing of the harness due to wear or heat.
• Water getting into the connector or circuitry.
• Human error (mistakenly shorting a circuit, etc.).

INSPECTING THE MFI SYSTEM

1. Engine is hard to start or does not start at all
2. Unstable idle
3. Poor driveability

ON-BOARD DIAGNOSTICS

• Diagnostic trouble codes are set as follows:
After the PCM first detects a malfunction, a diagnostic trouble code is recorded when the engine is restarted and the
same malfunction is re-detected. (Themalfunction is detected in driving cycle). However, for fuel system rich/lean
misfiring, a diagnostic trouble code is recorded on the first detection of the malfunction.
• Erasing diagnostic trouble codes:
After recording the diagnostic trouble code, if the PCM does not re-detect the malfunction for 40 driving cycles, the
diagnostic trouble code will be erased from the PCM memory. However, for fuel system rich/lean or misfiring,the
diagnostic trouble code will be erased if both of the following conditions are met:
- When driving conditions (engine speed, engine coolant temperature, etc.) are identical to those when the
malfunction was first recorded.
- When the PCM does not re-detect the malfunction for 80 driving cycles.
A "driving cycle" is complete as soon as the vehicle goes into closed-loop operation.
• Catalyst
• Fuel system
• Air flow sensor (MAF sensor)
• Intake Air Temperature Sensor (IAT sensor)
• Engine Coolant Temperature Sensor (ECT sensor)
• Throttle Position Sensor (TPS)
• Front Oxygen Sensor
• Rear Oxygen Sensor Heater
• Rear Oxygen Sensor
• Front Oxygen Sensor Heater
• Injector
• Misfire
• Crankshaft Position Sensor (CKP sensor)
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24.04.2008