Flag 54: 5-Volt Reference Ground

Flag will set if MAP sensor signal, linear EGR sensor signal and TPS signal are all zero volts. With ignition switch in OFF position, disconnect PCM harness connector. Check resistance to ground on harness terminals J2B05, J2B06 and J2A06. If resistance is less than 2 ohms, repair short to ground in faulty circuit. If resistance is not less than 2 ohms, check PCM harness connector terminal tightness. If harness connector terminals are okay and scan indicates low voltage on all 3 circuits, replace PCM.