Note On Intermittents

If intermittent Code EO20 is stored, unplug oil pressure switch. Start engine, allow it to idle, and manipulate affected wiring. Ensure ECM connectors are properly latched and relay is properly installed in relay center socket. If fault is induced, the engine will stall and Code EO20 will set. If Code EO20 sets without stall, cause is an intermittent open in circuit No. 120 between ECM terminal E13 and splice to fuel pump relay.

Fig 1: ECM Code EO20 Circuit Diagram

Fig 2: ECM Code EO20 Flow Chart (1 of 2)

Fig 3: ECM Code EO20 Flow Chart (2 of 2)