B2739

Diagnostic Trouble Code (DTC) Chart (Part 1 Of 2):

Diagnostic Trouble Code (DTC) Chart (Part 2 Of 2):

Wiring Schematic:

CIRCUIT DESCRIPTION
The BCM interfaces with the key in ignition switch. The key in ignition switch grounds circuit 80 when the key is fully inserted in the ignition switch. The key in ignition switch opens when key is removed from the ignition switch. The BCM uses this input for the operation of the key in the ignition reminder, exit illumination, and lockout prevention. The key in ignition switch receives ground through circuit 1550.

CONDITIONS FOR SETTING THE DTC
1. The BCM does not detect a ground signal in circuit 80 when the BCM is detecting voltage in circuit 1500.
2. All conditions must be present for more than 0.3 seconds.

ACTIONS TAKEN WHEN THE DTC SETS
The BCM stores DTC B2739 in memory.

CONDITIONS FOR CLEARING THE DTC
^ The BCM receives a key in ground signal (circuit 80) when the ignition switch is not off, then the BCM changes the DTC status from current to history.
^ A history DTC will clear after 100 consecutive ignition cycles if the condition for the fault 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 ground in circuit 80.
^ An intermittent open in circuit 1550.
^ Poor connections at the BCM or the key in ignition switch.
^ An intermittent open in G203.
^ Faulty ignition switch.
^ The BCM is open internally.
^ DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is on with the Body Control Module (BCM) disconnected. When BCM diagnostics and repairs are completed, refer to A Powertrain On Board Diagnostic (OBD) System Check for additional information on PCM related DTCs in Computers and Control Systems Testing.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step determines whether circuit 80 or 1550 is open, or the ignition key alarm switch is faulty (contacts always open).
4. This step checks for either short to ground in circuit 80 or a faulty ignition key alarm switch (contacts always closed).
5. This step determines whether the malfunction is intermittent or the BCM is faulty.
6. This step checks for an open in circuit 1550.
7. This step checks for either an open in circuit 80 or a faulty ignition key alarm switch.
8. This step checks for either a short to ground in circuit 80 or a faulty ignition key alarm switch.