Leganza SX L4-2.2L DOHC D-TEC MFI (1999)
Steps 12 - 22
Test Description
Number(s) below refer to the step number(s) on the diagnostic table.
1. The On-Board Diagnostic (OBD II) System Check prompts the technician to complete some basic checks and store the freeze frame and failure
records data on then scan tool, if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is
stored in the scan tool for later reference.
3. Connections that are suspected of being faulty should be thoroughly checked as described in the diagnostic aids.
4. If the engine fails to start and the MIL is inoperative, then the fault can be isolated to either the ECM ignition feed, the battery feed, or a poor
ground at the engine block or the ECM.
6. Probing the MIL circuit with a test light to ground stimulates the ECM's control of the MIL. If the MIL illuminates, then the malfunction can be
isolated to the control of the MIL or a poor connection at the MIL terminal to the ECM. Connections that are suspected of being faulty should be
thoroughly checked as described in the diagnostic aids.
8. It takes very little resistance for the battery and ignition feed circuits to cause an intermittent condition and should also be checked for a poor
connection as described in diagnostic aids.
11. Before replacing the ECM, check for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor
terminal-to-wiring harness. Replacement ECMs must be reprogrammed. Refer to Powertrain Control Module / Service and Repair.
20. ECM grounds will only cause a problem if all of the grounds are not making a good connection. If an ECM ground problem is suspected, the most
probable place to check is where all the grounds meet, at the engine block.
22. If not faults have been found at this point and no DTCs were set, refer to the diagnostic aids for additional checks and information.
