DTC P1510 - Pcm Back-Up Power Supply Malfunction

Using a voltmeter, measure voltage (backprobe) between ground and PCM harness connector "A", terminal No. 14 with ignition off, then engine running. Reading should be 10-14 volts for each condition. If reading is as specified, check for poor connection at PCM. Repair as necessary. If connections are okay, replace PCM. If reading is not as specified, repair open White wire between relay/fuse box and PCM. Retest system.