Operation CHARM: Car repair manuals for everyone.

Code .7.9 Reset Circuit

Fig. 33 Fuel data wiring circuit:





The ``reset'' line, circuit 464, is grounded by depressing the ``reset'' button on the fuel data panel. Code .7.9 indicates that the ECM is not receiving a zero voltage signal when the ``reset'' button is depressed.
1. Turn ignition on, then remove fuel data panel electrical connector.
2. Connect jumper wire between pin E of harness and ground.
3. If code .7.9 passes after removing jumper wire, check circuit 990 (1985, 155) for open and repair as necessary. If circuit is satisfactory, check for faulty connector or fuel data panel.
4. If code .7.9 remains after removing jumper wire, check circuit 464 for an open or short circuit and repair as necessary. If circuit is satisfactory, check for faulty ECM or ECM connector.