B2735

DTC B2735 Pass-Key (R) II Programming Mode Active:

CIRCUIT DESCRIPTION
The PASS-Key (R) II detection circuit is completed by the PASS-Key (R) II (with embedded resistor pellet) in the ignition lock cylinder. Contacts in the ignition lock cylinder mate with those on the pellet, and the Body Control Module (BCM) compares the resistance value of the key pellet to the valid resistance programmed into the BCM.
If the proper resistance value is read, the BCM sends a password via the Class II serial data link to the Powertrain Control Module (PCM). As a result, the PCM energizes the theft deterrent relay, and allows fuel deliver to the engine.
When a BCM is replaced, it must be programmed to accept the resistance value of the existing vehicle keys to allow PASS-Key (R) II operation. When the BCM is replaced, the service replacement BCM is programmed to accept the first PASS-Key (R) II resistance value it detects. If the BCM is unable to detect a valid PASS-Key (R) II resistance value, the BCM will never end the programming sequence and a DTC B2735 will set.

CONDITIONS FOR SETTING THE DTC
^ The BCM is unable to detect a valid PASS-Key (R) II code during programming of a service replacement BCM, due to other malfunctions present (i.e. an open or short in the PASS-Key (R) II circuit).

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC 132735 in the BCM memory.
^ Sends a message to the instrument Panel Cluster (IPC) to turn on the SECURITY indicator.
^ The BCM sends a message to the PCM via Class II serial data link to:
- Enable the theft deterrent relay.
- Deliver fuel to the engine.
- The engine will start.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC B2735 clears when the BCM is able to detects a valid PASS-Key (R) II resistance value.
^ 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
^ If there is an open or short on circuit 1073 or circuit 1074, the BCM will be unable to accept a valid PASS-Key (R) II code when the program mode is activated.
^ Always diagnose a DTC B2722 or B2723 before attempting to diagnose a DTC B2735, as this will affect the BCM's ability to properly read a PASS-Key (R) II resistance value.
^ Make sure the key resistor contacts are clean and free of any grease. oil, etc. These substances could interfere with the key detection circuit, causing the BCM to be unable to program the PASS-Key (R) II system and to set a DTC B2735.
^ If DTC B2735 is a history DTC, this indicates that the BCM had previously entered and successfully completed the programming mode. Clear the DTCs in the BCM and recheck the system.
^ DTC P1626 will set in the 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 B2735.
2. Checks if the BCM was programmed to the PASS-Key (R) II system.
3. Checks if DTC B2722 or B2735 are stored in the BCM's memory.
4. Checks if a DTC B2735 will set as current.