P0656
Fuel Level Output Circuit
- Severity
- Low
- Driving
- Drivable — book it in
A fault in the fuel level output circuit. The module cannot pass the fuel level on to whatever uses it - the gauge, the range calculation, or the misfire detection logic that needs to know the tank is not nearly empty. A very low tank causes misfires that are not faults, which is why the module wants this reading.
Possible causes
- CommonWiring or connector fault on the output circuit
- CommonCorroded connector at either end
- PossibleFault in the module receiving the signal, loading the circuit
- PossibleChafed harness shorting against the body or engine
- PossibleAftermarket equipment spliced into the circuit
- RareFailed control module output driver
- CommonFaulty fuel level sender in the tank
What you might notice
- Fuel gauge wrong or dead
- Range calculation implausible
- Misfire codes appearing when the tank is nearly empty
- Check engine light on
What to check, in order
- Check whether the fuel gauge reads correctly. A wrong gauge points at the sender in the tank rather than at this output circuit.
- Inspect the connectors and wiring.
- Note that running consistently on a very low tank causes genuine misfires as the pump draws air, and can shorten the fuel pump's life.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Computer output circuits and control module
P0600P0601P0602P0603P0604P0605P0606P0607P0608P0609P0610P0611P0612P0613P0614P0615P0616P0617P0618P0619P0620P0621P0622P0623P0624P0625P0626P0627P0628P0629P0630P0631P0632P0633P0634P0635P0636P0637P0638P0639P0640P0641P0642P0643P0644P0645P0646P0647P0648P0649P0650P0651P0652P0653P0654P0655P0656P0657P0658P0659P0660P0661P0662P0663P0664P0665P0666P0667P0668P0669P0670P0671P0672P0673P0674P0675P0676P0677P0678P0679P0680P0681P0682P0683P0684P0685P0686P0687P0688P0689P0690P0691P0692P0693P0694P0695P0696P0697P0698P0699