P0230

Circuit Description
The Fuel Pump relay coil is supplied power via the Engine Controls Power Relay (Switched B+). The Engine Control Module (ECM) controls the relay by grounding the control circuit via an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the ECM. When the ECM is commanding a component on, the voltage of the control circuit should be low (near 0 volts). When the ECM is commanding the control circuit to a component off, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, this DTC will set.

When the ECM detects any reference pulses from the crankshaft position sensor, the ECM will enable the fuel pump. The relay is used in order to control the high current flow to the fuel pump. This allows the ECM driver to only have to handle the relatively low current used by the relay.

Conditions for Running the DTC
^ The battery voltage is between 7.5-15 volts.
^ Shorts to ground and open circuits are tested only during the powerdown phase.
^ Shorts to battery voltage are tested continuously. The engine RPM must be more than 40 RPM.

Conditions for Setting the DTC
A short to ground, an open circuit, or a short to battery voltage detected on the control circuit.

Action Taken When the DTC Sets
The ECM illuminates the Malfunction Indicator Lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.

Conditions for Clearing the MIL/DTC
^ The ECM turns off the MIL after three consecutive drive trips that the diagnostic runs and passes.
^ A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic.
^ The ECM battery voltage is interrupted.
^ The scan tool clears the MIL/DTC.

Diagnostic Aids

Notice: Refer to J 35616-A Connector Test Adapter kit Notice in Service Precautions.

Use the J 35616-A connector test adapter kit for any test that requires probing the ECM harness connector or a component harness connector.

Check for the following conditions:
^ Poor connections at the ECM or at the component-Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
^ Inspect all circuits that are spliced to the fuel pump relay B+ circuits for the proper operation.
^ Damaged harness-Inspect the wiring harness for any damage. If the harness appears to be OK, observe the scan tool while moving the related connectors and the wiring harnesses. A change in the display may help in order to locate the fault.

Refer to Symptoms for the Intermittent Condition. Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. Listen for an audible click when the relay operates. Repeat the commands as necessary.
3. This check can detect a partially shorted coil which would cause an excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When warm, the coil may open (amps drop to 0), or short (goes above 0.20 amp).
15. Perform the Idle Learn Procedure when replacing the ECM or the throttle body.