Help with two codes
P0463 H C Fuel Level Sensor Circuit High Voltage
P0654 H C Engine Speed Output Circuit
Can anyone tell me what may be causing these problems.
P0463: When fuel level is high the fuel sender sends a high voltage to the PCM. If the PCM detects a higher voltage than the correct "full" level voltage you get this code. Either the sender is bad or maybe just using some Techron can correct the condition. Note, this code is only for the Left/Drivers side fuel level sensor.
P0654: The PCM takes the engine speed (rpm) signal and matches it by pulsing a PCM circuit to ground to exactly match the incoming signal. If the PCM output does not match the input you get this code. One of following could be the problem, will try and think if there might be more.
PCM is defective
PCM circuit ground for this is not making good contact.
PCM output connector may be corroded and affecting the ground (check the PCM for possible battery acid damage/leakage)
The Instrument Panel Cluster (IPC) or wiring could be bad affecting the PCM output/ grounding circuit
With that said, does the IPC tachometer seem erratic? I would think you could notice some problem since it seems that the PCM is not providing an output that matches it's input signal. The code is supposed to be thrown if this signal mismatch lasts for more than 5 seconds.
I can post the PCM connector pins for the grounds and any other info you need. Am not at home now so I can't scan my FSM.
Hope this helps, will provide any more help if you need it. Just let me know. We can talk over the phone too, just PM me with your number and I will return with my number also.
Mr. Sam
PS: Also try disconnecting the battery for several minutes and reconnecting. Sometimes a simple reboot of computer modules can fix a problem. At least it is a simple and free fix if it works.
Last edited by dadaroo; May 9, 2013 at 03:26 PM.



