Diagnostic Aid

WARNING: This page is about a different car, the 1995 Mazda MX-6 and 1995 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.

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). Turn ignition off. Disconnect PCM 60-pin connector and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (49-UN01-058), leaving PCM disconnected. Measure voltage between test pin No. 1 and test pin No. 40 or 60 at breakout box. Observe DVOM while wiggling small sections of EEC-IV wiring harness from PCM to dash. If voltage is less than 10.5 volts, repair open circuit. Remove breakout box, reconnect all components and repeat QUICK TEST. If reading is 10.5 volts or more, go to next step.

2) Inspect Wiring Harness Routing Ensure EEC-IV wiring is not routed close to ignition components and secondary ignition wires. If necessary, reroute EEC-IV wiring. Clear codes and wait 5 minutes. Repeat KOEO SELF-TEST. If Continuous Memory Code 512 is not repeated, service other codes as necessary. If no other codes are present, testing is complete. If Continuous Memory Code 512 is still present, replace PCM and repeat QUICK TEST.