Code .7.4 Reverse Circuit

Fig. 31 Reverse switch wiring circuit:

1. Trouble code .7.4 indicates that the ECM is not receiving the signal from the back-up light switch that indicates transmission in reverse. Signal is produced by operating the back-up light switch, Fig. 31. Check operation of back-up lights.
2. If back-up lights operate, fuse is not blown, and circuit No. 75 is satisfactory. An open circuit No. 24 could cause code No. 74. To check circuit No. 24, connect a jumper wire to ground and the back-up light switch terminal with two light green wires. Disconnect the orange ECM connector and probe circuit 24 harness pin with ohmmeter connected to ground. An infinite reading indicates an open circuit in circuit 24. A zero reading indicates that continuity exists. ECM or ECM connector is at fault.