DTC 1111

^ Electronic control unit fault. When this code is present, one of the control units has detected a fault in an internal circuit, and may need to be replaced. If this code was observed during the ignition control unit's fault memory display, then the fault is with that unit. If this code was displayed by the fuel control ECU, then the fault is with that ECU. If this code is present along with other codes, check the circuits indicated by the other codes first, repair as necessary, clear all codes and recheck fault memory. If this code is present alone, check all engine grounds and all ECU ground wires for good connections to ground (not more than 0.2 ohms resistance across any connector). Also check all the fuses and the fuel pump relay. Make any necessary repairs, clear fault memory and re-test the vehicle. You might fix the problem without replacing a control unit.

NOTE: Internal faults can be caused by a number of external conditions, such as improper testing procedures, improper installations of add on accessories or other electrical tampering, shorts to power or ground in wiring harness, or faults in peripheral devices. Before installing a new ECU, be sure that all external circuits and devices are OK or you may risk damaging the new unit.