Measure voltage between ECM/PCM connector terminals A24 and E16. ECM/PCM CONNECTORS Wire side of female terminals Is there battery voltage? YES - Replace the PSP switch. NO - Go to step 15. Turn the ignition switch OFF. Disconnect ECM/PCM connector E (31P). Check for continuity between body ground and ECM/PCM connector terminal E16. ECM/PCM CONNECTOR E (31P) Wire side of female terminals Is there continuity? YES - Repair short in the wire between ECM/PCM (E16) and the PSP switch. NO - Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.