code 63: the KOEO code 63 indicates the TP signal voltage is low. disconnect the TP sensor harness. place a jumper wire between the VREF wire [usually orange] and the TP signal wire [usually dark green and light green]. repeat the KOEO test. if the code 63 returns, check for 5 volts at the orange VREF wire. if the VREF wire has 5 volts, repair the TP signal wire to the ECA. if the orange wire does not have 5 volts, confirm that the ignition switch was on when the voltage was tested and repair the orange wire.
if the code 53 was generated when the KOEO test was repeated, replace the TP sensor.
if the code 63 was received during the memory codes, perform the continous monitor test[see the "supplemental EEC IV tests" section as the end of this chapter]. repair the wiring, connector, or sensor as required.