B2739

DTC B2739 Key In Ignition Fault:

DTC B2739 Key In Ignition Fault (Part 1 Of 2):

DTC B2739 Key In Ignition Fault (Part 2 Of 2):

CIRCUIT DESCRIPTION
When the ignition key is fully inserted in the ignition switch, the Body Control Module (BCM) receives a ground input in circuit 80 from ignition key alarm switch. If the BCM detects IGN0 active (ignition switch rotated out of the OFF position) without receiving the ground signal in circuit 80, a fault condition is present and the BCM will set DTC B2739.
^ BCM does not detect a ground in circuit 80 when the BCM is detecting battery voltage on IGN0.
^ All conditions must be present for more than 0.3 seconds.

CONDITIONS FOR SETTING THE DTC
^ The BCM does not detect a ground in circuit 80 when the BCM is detecting battery voltage on IGN0.
^ All conditions must be present for more than 0.3 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC B2739 in the BCM memory.
^ No driver warning message will be displayed for this DTC.

CONDITIONS FOR CLEARING THE DTC
^ The BCM receives a key in signal (ground) when the ignition switch is not in the OFF position, then the BCM moves DTC B2739 from current DTC to history DTC.
^ A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Using a scan tool.

DIAGNOSTIC AIDS
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent open or short to voltage in circuit 80.
- An intermittent open in circuit 1550.
- Poor connections at the BCM, or the ignition key alarm switch.
- BCM shorted to voltage internally.
- An intermittent open in G203.
^ If the BCM is open internally.
^ DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is in the RUN position with the BCM disconnected.

TEST DESCRIPTION
Numbers below refer to the step numbers on the diagnostic table.
1. Always perform the BCM Diagnostic System Check before attempting to diagnose a DTC B2739.
2. Checks for a short to B+ in circuit 80.
3. Determines if there is a short to B+ in circuit 80 or the Ignition Key Alarm Switch.
4. Checks for an open in circuit 80.
8. Checks for a short to ground in circuit 80.
10. Checks for an open in the ignition key alarm switch.