P0231

DTC P0231 Fuel Lift Pump Secondary Circuit Low Voltage






Circuit Description

The status of the lift pump is monitored by the PCM. This signal is also used to store a DTC if the fuel pump relay is defective or fuel pump voltage is lost while the engine is running. There should be about 12 volts on circuit 12O during glow plug cycle. This is a Type B DTC.

Conditions for Setting the DTC

^ Fuel lift pump commanded "ON".
^ Ignition voltage minus 4 volts.
^ Fuel lift pump voltage less than ignition voltage value.
^ Conditions met for 2 seconds.

Action Taken When the DTC Sets

No action taken.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL off after three consecutive trips without a fault condition.
^ A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (16O°F) that same ignition cycle).
^ Use of a Scan Tool

Diagnostic Aids

This DTC will not check the fuel pump operation.

Test Description

Number(s) below refer to the number(s) on the diagnostic table.

3. This step will check the fuel pump circuit.