P1222

DTC P1222 Fuel Pump Voltage Low:

Fuel Pump Circuit:

CIRCUIT DESCRIPTION
The status of the fuel pump CKT 120 is monitored by the Vehicle Control Module (VCM) at terminal "GR20" and is used to compensate fuel delivery based on system voltage. 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 CKT 120 for at least 2 seconds after the ignition is turned "ON," or when reference pulses are being received by the VCM.

The DTC will help the diagnosis of an engine that "Cranks But Will Not Run."

DTC P1222 WILL SET WHEN
DTC P1222 will set when voltage at "GR20" is less than 2 volts for 1.5 seconds since the last reference pulse.

ACTION TAKEN (VCM WILL DEFAULT TO)
No action taken. The oil pressure switch will provide voltage to the fuel pump when it closes. This could result in an extended crank time, especially when cold.

DTC P1222 WILL CLEAR WHEN
Conditions for fault are no longer present and Tech 1 clear DTCs function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and Fuse #9 is removed for 10 seconds.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Check to see if DTC P1222 was set as result of a hard failure or intermittent condition.
2. Checks pump relay.
3. Checks CKT's 440 and 151.
4. Checks CKT 465 connections at relay and VCM.
5. Checks oil pressure switch and connections.

DIAGNOSTIC AIDS
Fuel pump should run for 2 seconds and then turn "OFF" if the VCM senses no reference pulses. The fuel pump relay is located in the convenience center.