P1262

CIRCUIT DESCRIPTION
The Fuel Injector Control Module (FICM) supplies the voltage for each fuel injector. The fuel injector ignition voltage circuit is Pulse Width Modulated (PWM), between 20 volts at idle, to approximately 93 volts in order to compensate for increased engine load and RPM. The fuel injector control module energizes each fuel injector by grounding the command circuit between the fuel injector control module and the fuel injector. The fuel injector control module monitors the status of the ignition voltage circuits and the fuel injector command circuits. When a fuel injector circuit condition is detected by the fuel injector control module, all of the fuel injectors on the affected ignition voltage circuit will be disabled. If a circuit condition is detected on a fuel injector circuit for cylinders 1, 4, 6, or 7, Diagnostic Trouble Codes (DTCs) P0201, P0204, P0206, P0207 will set, along with DTC P1261. If a circuit condition is detected on a fuel injector circuit for cylinders 2, 3, 5, or 8, DTCs P0202, P0203, P0205, P0208 will set, along with DTC P1262. If only DTC P1261 or P1262 is set, an internal FICM problem is at fault.

CONDITIONS FOR RUNNING THE DTC
^ The ignition is ON.
^ DTC U1800, or U2104 are not set.

CONDITIONS FOR SETTING THE DTC
The ECM detects a circuit fault related to the high voltage circuit to cylinders 2, 3, 5, and 8.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

TEST DESCRIPTION

Steps 1-5:

The number below refers to the step number on the diagnostic table.
2. This step determines if a wiring or injector problem caused this DTC to set. If DTC P1262 sets alone, an internal FICM fault is the cause.