Engine Controls - Tests W/codes: Diagnosis Mitsubishi Galant VIII

SYSTEM DIAGNOSIS

Note. PCM diagnostic memory is retained by direct power supply from battery. Memory is not erased by turning off ignition, but it will be erased if battery or PCM is disconnected.

System diagnosis can be accomplished using a scan tool on all models. See ENTERING ON-BOARD DIAGNOSTICS . Powertrain Control Module (PCM) monitors several different engine control system circuits. If an abnormal input signal occurs, a Diagnostic Trouble Code (DTC) is stored in PCM memory and assigned a DTC number. Each circuit has its own DTC number and message. A specific DTC indicates a particular system failure, but does not indicate that cause of failure is necessarily within system.

A DTC does not condemn any specific component; it simply points out a probable malfunctioning area. If a DTC is set, PCM will turn on MIL. System failures encountered are identified as either hard failures or intermittent failures as determined by PCM.

VISUAL INSPECTION

Most driveability problems in the engine control system result from faulty wiring, poor electrical connections or leaking air and vacuum hose connections. To avoid unnecessary component testing, perform a visual inspection before beginning self-diagnostic tests.

ENTERING ON-BOARD DIAGNOSTICS

Note. DO NOT skip any steps in self-diagnostic tests or incorrect diagnosis may result. Ensure self-diagnostic test applies to vehicle being tested.

DTCs may be retrieved by using a scan tool only. Proceed to appropriate DTC retrieval method.

Note. Although other scan tools are available, Mitsubishi recommends using Multi-Use Tester II (MUT II) scan tool.

Using Scan Tool

1. Refer to manufacturer's operation manual for instructions in use of scan tool. Before entering on-board diagnostics, see SERVICE PRECAUTIONS. Locate Data Link Connector (DLC) under instrument panel, near steering column.
2. Turn ignition switch to OFF position. Connect scan tool to DLC. Turn ignition switch to ON position. Read and record scan tool self-diagnostic output. Proceed to DIAGNOSTIC TROUBLE CODES (DTCS).

TROUBLE CODES

Note. DTCs can only be retrieved by using a scan tool. DTCs listed below are retrieved using a generic scan tool. MUT II scan tool can be used, but it may not read all DTCs. DTCS listed are not used on all vehicles.

DIAGNOSTIC TROUBLE CODE (DTC) INDEX

DIAGNOSTIC TESTS

Note. PCM diagnostic memory is retained by direct power supply from battery. Memory is not erased by turning off ignition, but it will be erased if battery or PCM is disconnected.

Note. Perform all resistance and voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm impedance, unless stated otherwise in test procedures.

Multi-Use Tester II (MUT II) scan tool has 2 modes of operation; generic scan tool mode and MUT II mode. Perform all Diagnostic Trouble Code (DTC) tests using generic scan tool mode, unless stated otherwise in test procedures. All DTC tests are listed using generic scan tool DTCs.

Using scan tool, display and record DTCs. See ENTERING ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS section. If no DTCs are displayed, see TESTS W/O CODES article.

Clear DTCs. See CLEARING DTCS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICSsection. Road test vehicle (if necessary) and attempt to duplicate conditions that caused original complaint. Recheck for DTCs. If no DTCs are displayed, go to INTERMITTENT DTCS. If one or more DTCs are displayed, repair DTCs in order starting with lowest numbered DTC. Clear DTCs after each repair. Recheck for DTCs to confirm repair.

SCAN TOOL WILL NOT COMMUNICATE

Note. For terminal identification, see TERMINAL IDENTIFICATION in SELF-DIAGNOSTICS section. For circuit and wire color identification, see WIRING DIAGRAMS article.