Sonata V6-3.0L (1991)
ECU System
NOTE: Before replacing a ECU that is found to be faulty, insure that no other condition exists that will damage the new unit. This can be best done
by testing the inputs and outputs to the ECU for over voltage/inappropriate power readings or grounds. Use the ECU Terminal Identification image
and the individual component testing procedures to Identify the correct readings for each pin. Check all pins (at the harness with the ECU removed)
that supply a signal to the ECU, for their correct readings and check all other pins to insure that there are no uncalled for voltage readings or
grounds present.
3.
Compare all the remaining codes to the following list and perform the required inspections called for in each of the categories that are affected by a
code.
Check power supply for:
1. Faulty battery.
2. Faulty fusible link.
3. Faulty fuse.
4. Check for faulty body ground.
Check Fuel supply for:
1. Damaged fuel line.
2. Clogged or damaged fuel filter.
3. Faulty fuel pump.
Check ignition system for:
