Diagnostic Aid

Continuous Memory Code 512 may be displayed when power between PCM and KAPWR is interrupted. This code may be set when a breakout box is installed or battery is disconnected.

1) Continuous Memory Code 512: Check KAPWR Circuit Voltage  Code 512 indicates PCM power interruption in Keep-Alive Memory (KAM). Clear codes and repeat QUICK TEST. If Code 512 is repeated, turn ignition off. Disconnect 60-pin PCM connector. Inspect terminals and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure voltage between test pin No. 1 and test pins No. 40 or 60 at breakout box. Observe voltage reading while wiggling small sections of EEC wiring harness from PCM to dash. If reading is less than 10.5 volts, repair open circuit and repeat QUICK TEST. If reading is 10.5 volts or more, go to next step.

2) Inspect Wiring Harness Routing  Ensure EEC wiring is not routed close to ignition components and secondary ignition wires. If necessary, reroute EEC wiring. Clear codes and wait 5 minutes. Repeat KOEO SELF-TEST. If Continuous Memory Code 512 is not repeated, testing is complete. If Continuous Memory Code 512 is still present, replace PCM and repeat QUICK TEST.