| TIBURON(GK) >2008 > G 2.7 DOHC > Fuel System > General Information>Troubleshooting |

BASIC TROUBLESHOOTING
BASIC TROUBLESHOOTING GUIDE
CUSTOMER PROBLEM ANALYSIS SHEET
1. | VEHICLE INFORMATION
(I) VIN:
(II) Production Date:
(III) Odometer Reading: (km)
2. | SYMPTOMS
□ Unable to start | □ Engine does not turn over □ Incomplete combustion □ Initial combustion does not occur
□ Difficult to start | □ Engine turns over slowly □ Other_________________
□ Poor idling | □ Rough idling □ Incorrect idling □ Unstable idling (High: ______ rpm, Low: ______rpm) □ Other __________________________________
□ Engine stall | □ Soon after starting □ After accelerator pedal depressed □ After accelerator pedal released □ During A/C ON □ Shifting from N to D-range □ Other _______________________________________________
□ Others | □ Poor driving (Surge) □ Knocking □ Poor fuel economy □ Back fire □ After fire □ Other ____________________________
3. | ENVIRONMENT
Problem frequency | □ Constant □ Sometimes (_________________) □ Once only □ Other ___________________________________________
Weather | □ Fine □ Cloudy □ Rainy □ Snowy □ Other __________________
Outdoor temperature | Approx. _____ °C/°F
Place | □ Highway □ Suburbs □ Inner City □ Uphill □ Downhill □ Rough road □ Other ___________________________________
Engine temperature | □ Cold □ Warming up □ After warming up □ Any temperature
Engine operation | □ Starting □ Just after starting (____ min) □ Idling □ Racing □ Driving □ Constant speed □ Acceleration □ Deceleration □ A/C switch ON/OFF □ Other _____________________________
4. | MIL/DTC
MIL (Malfunction Indicator Lamp) | □ Remains ON □ Sometimes lights up □ Does not light
DTC | □ Normal □ DTC (_______________________________________) □ Freeze Frame Data
BASIC INSPECTION PROCEDURE The measured resistance at high temperature after vehicle running may be high or low. So all resistance must be measured at ambient temperature (20°C, 68°F), unless there is any notice.
The measured resistance in except for ambient temperature (20°C, 68°F) is reference value.
Sometimes the most difficult case in troubleshooting is when a problem symptom occurs but does not occur again during testing. An example would be if a problem appears only when the vehicle is cold but has not appeared when warm. In this case, technician should thoroughly make out a "CUSTOMER PROBLEM ANALYSIS SHEET" and recreate (simulate) the environment and condition which occurred when the vehicle was having the issue.
1. | Clear Diagnostic Trouble Code (DTC).
2. | Inspect connector connection, and check terminal for poor connections, loose wires, bent, broken or corroded pins, and then verify that the connectors are always securely fastened.
3. | Slightly shake the connector and wiring harness vertically and horizontally.
4. | Repair or replace the component that has a problem.
5. | Verify that the problem has disappeared with the road test.
● SIMULATING VIBRATION
1) | Sensors and Actuators : Slightly vibrate sensors, actuators or relays with finger.
Strong vibration may break sensors, actuators or relays
2) | Connectors and Harness : Lightly shake the connector and wiring harness vertically and then horizontally.
● SIMULATING HEAT
1) | Heat components suspected of causing the malfunction with a hair dryer or other heat sourre.
• | DO NOT heat components to the point where they may be damaged.
• | DO NOT heat the ECM directly.
● SIMULATING WATER SPRINKLING
1) | Sprinkle water onto vehicle to simulate a rainy day or a high humidity condition.
DO NOT sprinkle water directly into the engine compartment or electronic components.
● SIMULATING ELECTRICAL LOAD
1) | Turn on all electrical systems to simulate excessive electrical loads (Radios, fans, lights, etc.).
CONNECTOR INSPECTION PROCEDURE
1. | Handling of Connector
A. | Never pull on the wiring harness when disconnecting connectors.
B. | When removing the connector with a lock, press or pull locking lever.
C. | Listen for a click when locking connectors. This sound indicates that they are securely locked.
D. | When a tester is used to check for continuity, or to measure voltage, always insert tester probe from wire harness side.
E. | Check waterproof connector terminals from the connector side. Waterproof connectors cannot be accessed from harness side.
• | Use a fine wire to prevent damage to the terminal.
• | Do not damage the terminal when inserting the tester lead.
2. | Checking Point for Connector
A. | While the connector is connected: Hold the connector, check connecting condition and locking efficiency.
B. | When the connector is disconnected: Check missed terminal, crimped terminal or broken core wire by slightly pulling the wire harness. Visually check for rust, contamination, deformation and bend.
C. | Check terminal tightening condition: Insert a spare male terminal into a female terminal, and then check terminal tightening conditions.
D. | Pull lightly on individual wires to ensure that each wire is secured in the terminal.
3. | Repair Method of Connector Terminal
A. | Clean the contact points using air gun and/or shop rag.
Never use sand paper when polishing the contact points, otherwise the contact point may be damaged.
B. | In case of abnormal contact pressure, replace the female terminal.
WIRE HARNESS INSPECTION PROCEDURE
1. | Before removing the wire harness, check the wire harness position and crimping in order to restore it correctly.
2. | Check whether the wire harness is twisted, pulled or loosened.
3. | Check whether the temperature of the wire harness is abnormally high.
4. | Check whether the wire harness is rotating, moving or vibrating against the sharp edge of a part.
5. | Check the connection between the wire harness and any installed part.
6. | If the covering of wire harness is damaged; secure, repair or replace the harness.
ELECTRICAL CIRCUIT INSPECTION PROCEDURE
1. | Procedures for Open Circuit
A. | Continuity Check
B. | Voltage Check
If an open circuit occurs (as seen in [FIG. 1]), it can be found by performing Step 2 (Continuity Check Method) or Step 3 (Voltage Check Method) as shown below.
2. | Continuity Check Method
When measuring for resistance, lightly shake the wire harness above and below or from side to side.
Specification (Resistance) 1Ω or less → Normal Circuit 1MΩ or Higher → Open Circuit
A. | Disconnect connectors (A), (C) and measure resistance between connector (A) and (C) as shown in [FIG. 2]. In [FIG.2.] the measured resistance of line 1 and 2 is higher than 1MΩ and below 1 Ω respectively. Specifically the open circuit is line 1 (Line 2 is normal). To find exact break point, check sub line of line 1 as described in next step.
B. | Disconnect connector (B), and measure for resistance between connector (C) and (B1) and between (B2) and (A) as shown in [FIG. 3]. In this case the measured resistance between connector (C) and (B1) is higher than 1MΩ and the open circuit is between terminal 1 of connector (C) and terminal 1 of connector (B1).
3. | Voltage Check Method
A. | With each connector still connected, measure the voltage between the chassis ground and terminal 1 of each connectors (A), (B) and (C) as shown in [FIG. 4]. The measured voltage of each connector is 5V, 5V and 0V respectively. So the open circuit is between connector (C) and (B).
4. | Test Method for Short to Ground Circuit
A. | Continuity Check with Chassis Ground
If short to ground circuit occurs as shown in [FIG. 5], the broken point can be found by performing below Step 2 (Continuity Check Method with Chassis Ground) as shown below.
5. | Continuity Check Method (with Chassis Ground)
Lightly shake the wire harness above and below, or from side to side when measuring the resistance.
Specification (Resistance) 1Ω or less → Short to Ground Circuit 1MΩ or Higher → Normal Circuit
A. | Disconnect connectors (A), (C) and measure for resistance between connector (A) and Chassis Ground as shown in [FIG. 6]. The measured resistance of line 1 and 2 in this example is below 1 Ω and higher than 1MΩ respectively. Specifically the short to ground circuit is line 1 (Line 2 is normal). To find exact broken point, check the sub line of line 1 as described in the folowing step.
B. | Disconnect connector (B), and measure the resistance between connector (A) and chassis ground, and between (B1) and chassis ground as shown in [FIG. 7]. The measured resistance between connector (B1) and chassis ground is 1Ω or less. The short to ground circuit is between terminal 1 of connector (C) and terminal 1 of connector (B1).
SYMPTOM TROUBLESHOOTING GUIDE CHART
MAIN SYMPTOM | DIAGNOSTIC PROCEDURE | ALSO CHECK FOR
Unable to start (Engine does not turn over) |
1. | Test the battery
2. | Test the starter
3. | Inhibitor switch (A/T) or clutch start switch (M/T)
Unable to start (Incomplete combustion) |
1. | Test the battery
2. | Check the fuel pressure
3. | Check the ignition circuit
4. | Troubleshooting the immobilizer system (In case of immobilizer lamp ON)
• | DTC
• | Low compression
• | Intake air leaks
• | Slipped or broken timing belt
• | Contaminated fuel
Difficult to start |
1. | Test the battery
2. | Check the fuel pressure
3. | Check the ECT sensor and circuit (Check DTC)
4. | Check the ignition circuit
• | DTC
• | Low compression
• | Intake air leaks
• | Contaminated fuel
• | Weak ignition spark
Poor idling (Rough, unstable or incorrect Idle) |
1. | Check the fuel pressure
2. | Check the Injector
3. | Check the long term fuel trim and short term fuel trim (Refer to CUSTOMER DATASTREAM)
4. | Check the ISCA and ISCA circuit (Check DTC)
5. | Inspect and test the Throttle Body
6. | Check the ECT sensor and circuit (Check DTC)
• | DTC
• | Low compression
• | Intake air leaks
• | Contaminated fuel
• | Weak ignition spark
Engine stall |
1. | Test the Battery
2. | Check the fuel pressure
3. | Check the ISCA and ISCA circuit (Check DTC)
4. | Check the ignition circuit
5. | Check the CKPS Circuit (Check DTC)
• | DTC
• | Intake air leaks
• | Contaminated fuel
• | Weak ignition spark
Poor driving (Surge) |
1. | Check the fuel pressure
2. | Inspect and test Throttle Body
3. | Check the ignition circuit
4. | Check the ECT Sensor and Circuit (Check DTC)
5. | Test the exhaust system for a possible restriction
6. | Check the long term fuel trim and short term fuel trim (Refer to CUSTOMER DATASTREAM)
• | DTC
• | Low compression
• | Intake air leaks
• | Contaminated fuel
• | Weak ignition spark
Knocking |
1. | Check the fuel pressure
2. | Inspect the engine coolant
3. | Inspect the radiator and the electric cooling fan
4. | Check the spark plugs
• | DTC
• | Contaminated fuel
Poor fuel economy |
1. | Check customer's driving habits
• | Is A/C on full time or the defroster mode on?
• | Are tires at correct pressure?
• | Is excessively heavy load being carried?
• | Is acceleration too much, too often?
2. | Check the fuel pressure
3. | Check the injector
4. | Test the exhaust system for a possible restriction
5. | Check the ECT sensor and circuit
• | DTC
• | Low compression
• | Intake air leaks
• | Contaminated fuel
• | Weak ignition spark
Hard to refueling (Overflow during refueling) |
1. | Test the canister close valve
2. | Inspect the fuel filler hose/pipe
• | Pinched, kinked or blocked?
• | Filler hose is torn
3. | Inspect the fuel tank vapor vent hose between the EVAP. canister and air filter
4. | Check the EVAP. canister
• | Malfunctioning gas station filling nozzle (If this problem occurs at a specific gas station during refueling)