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| OBDI | |||
| Poslal: Drak Datum: 25.05.2010 - 21:36:58 Zobrazení: 2143 | |||
| Shrnutí: diagnostika pro vozy s ADLD protokolem | |||
OBD I GENERAL INFORMATION The Powertrain Control Module (PCM) monitors the signals of input and output sensors, some all the time and others at certain times and processes each signal. When the PCM notices that an irregularity has continued for a specified time or longer from when the irregular signal was initially monitored, the PCM judges that a malfunction has occurred and will memorize the malfunction code. The code is then stored in the memory of the PCM and is accessible through the data link (diagnostic connector) with the use of an electronic scan tool or a voltmeter. CHECK ENGINE/MALFUNCTION INDICATOR LIGHT Among the on-board diagnostic items, a check engine/malfunction indicator light comes on to notify the driver of a emission control component irregularity.lf the irregularity detected returns to normal or the PCM judges that the component has returned to normal, the check engine/malfunction indicator light will be turned off. Moreover, if the ignition is turned OFF and then the engine is restarted, the check engine/malfunction indicator light will not be turned on until a malfunction is detected. The check engine/malfunction indicator light will come on immediately after the ignition switch is turned ON. The light should stay lit for 5 seconds and then will go off. This indicates that the check engine/malfunction indicator lamp is operating normally. This does not signify a problem with the system. The check engine/malfunction indicator lamp will come on when the terminal for the ignition timing adjustment is shorted to ground. Therefore, it is not abnormal that the light comes on even when the terminal for ignition timing is shorted at time of ignition timing adjustment. To test the light, perform the following. 1. Turn the ignition switch ON. Inspect the check engine/malfunction indicator lamp for illumination. 2. The light should be lit for 5 seconds and then should go out. 3. If the lamp does not illuminate, check for open circuit in the harness, blown fuse or blown bulb. SERVICE PRECAUTIONS Before attaching or detaching the PCM harness connectors, make sure the ignition switch is OFF and the negative battery cable is disconnected to avoid the possibility of damage to the PCM. - When performing PCM inpuVoutput signal diagnosis, remove the pin terminal retainer from the connectors to make it easier to insert tester probes into the connector. - When attaching or detaching pin connectors from the PCM, take care not to bend or break any pin terminals. Check that there are no bends or breaks on PCM pin terminals before attempting any connections. - Before replacing any PCM, perform the PCM inpuVoutput signal diagnosis to make sure the PCM is functioning properly. - When measuring supply voltage of PCM-controlled components with a circuit tester, separate 1 tester probe from another. If the 2 tester probes accidentally make contact with each other during measurement, a short circuit will result and damage the PCM. READING CODES Remember that the diagnostic trouble code identification refers only to the circuit, not necessarily to a specific component. For example, fault code 14 may indicate an error in the throttle Position sensor circuit it does not necessarily mean the TPS sensor has failed. Testing of all related wiring, connectors and the sensor itself may be required to locate the problem, The PCM memory is capable of storing multiple codes. During diagnosis the codes will be transmitted in numerical order from lowest to highest, regardless of the order of occurrence. If multiple codes are stored, always begin diagnostic work with the lowest numbered code. Make a note of the following: 1. When battery voltage is low, no detection of failure is possible. Be sure to check the battery voltage and other conditions before starting the test. 2. Diagnostic items are erased if the battery or the engine controller connection is detached. Do not disconnect either of these components until the diagnostic material present in the PCM has been read completely. 3. Be sure to attach and detach the scan toolto the data link connector with the ignition key OFF. If the scan tool in connected or disconnected with the ignition key ON, diagnostic trouble codes may be falsely stored and the engine warning light may be illuminated. WITH A SCAN TOOL The procedure listed below is to be used only as a guide, when using Mitsubishi's MUT-II, or equivalent scan tool. For specific operating instructions, follow the directions supplied with the particular scan tool being used. 1. Remove the underdash cover, if equipped. Attach the scan tool to the data link connector, located on the left underside of the instrument panel. 2. Using the scan tool, read and record the on-board diagnostic output. 3. Diagnose and repair the faulty components as required. 4. Turn the ignition switch OFF and then turn it ON. 5. Erase the diagnostic trouble code. 6. Recheck the diagnostic trouble code and make sure that the normal code is output. WITHOUT A SCAN TOOL 1. Remove the under dash cover, if equipped. 2. Attach an analog voltmeter between the on-board diagnostic output terminal of the data link connector and the ground terminal. 3. Turn the ignition switch ON. 4. Read the on-board diagnostic output pattern from the voltmeter and record. 5. Diagnose and repair the faulty components as required. 6. Erase the trouble code. 7. Turn the ignition switch ON, and read the diagnostic trouble codes, checking that a normal code is output. TROUBLE CODES
 
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