B2735

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

DTC B2735 Pass-Key (R) II Programming Mode Active (Part 1 Of 2):

DTC B2735 Pass-Key (R) II Programming Mode Active (Part 2 Of 2):

CIRCUIT DESCRIPTION
The Personal Automotive Security System (PASS-Key(R) II) is a vehicle theft deterrent system. The PASS-Key(R) II is designed to prevent vehicle theft by disabling the engine from starting unless an ignition key with a specific resistor pellet code is used in the ignition lock cylinder.

The ignition lock cylinder contains the resistor sensing contacts. These contacts touch the resistor pellet embedded in the ignition key. When the ignition key is inserted in the ignition lock cylinder, the resistor pellet completes the key detection circuit (circuits 1073 and 1074).

When the ignition switch is turned from the LOCK or OFF to the RUN position, the Body Control Module (BCM) applies a 5V reference voltage to circuit 1073. Then, the BCM reads the resistor pellet code and compares the stored resistor pellet code against the ignition key resistor pellet code for a correct match.

Upon detecting a correct match, the BCM sends a fuel enable password to the Powertrain Control Module (PCM) through the Class II serial data link. As a result, the PCM enables the theft deterrent relay, and allows fuel delivery to the engine.

When replacing the BCM, it must be programmed to accept the resistance value of the existing vehicle keys to allow PASS-Key(R) II operation. A service replacement BCM is programmed to accept the first PASS-Key(R) II resistance value it detects.

CONDITIONS FOR SETTING THE DTC
^ The BCM is unable to detect a valid PASS-Key(R) II resistor pellet code during programming of a service replacement BCM.
^ This condition could be related to other malfunctions present (i.e. an open or short in circuit 1073 or 1074).

ACTION TAKEN WHEN THE DTC SETS
^ The BCM stores DTC B2735 in memory.
^ The BCM sends a message to the Instrument Panel Cluster (IPC) to turn on the SECURITY indicator through the Class II serial data link.
^ The BCM sends a message to the PCM through the 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 II system and to set a DTC B2735.
^ If DTC B2735 is a history DTC, this indicates that the BCM bad previously entered and successfully completed the programming mode. Clear the DTCs in the BCM and recheck the BCM system for DTCs.
^ DTC P1626 will set in the Powertrain Control Module (PCM) when the ignition switch is in the RUN position with the BCM disconnected. When BCM diagnostics and repairs are completed, refer to the Engine Controls for additional information on PCM related DTCs. Powertrain Management

TEST DESCRIPTION
Numbers below refer to the Step numbers on the diagnostic table.
2. Checks if DTC B2735 resets as a current DTC.
3. If BCM DTC B2722 or B2735 are present, perform the diagnostic tables for these DTCs first.