Circuit Description
Inserting the PASS-Key® (with resistor pellet) in the ignition lock cylinder completes the PASS-Key® circuit. Contacts in the ignition lock cylinder mate with the pellet contacts. The 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 allows the following functions to occur:
| • | The theft deterrent relay to energize. |
| • | The steering column to unlock. |
| • | The BCM sends a message through the serial data line to the PCM to allow fuel enable processing to occur. |
If the resistance value is incorrect, a malfunction is present and a DTC will set.
Conditions for Setting the DTC
| • | The voltage level sampled at the BCMs PASS-Key® input circuit is low, signaling that an invalid PASS-Key® resistance was detected, and a short to ground is present. |
| • | This condition must be present for 1 second. |
Action Taken When the DTC Sets
| • | Stores a DTC B2722 in the BCM memory. |
| • | Sends a message to the IPC to display the SECURITY indicator. |
| • | The BCM will disable the theft deterrent relay. |
| • | The PCM will not allow fuel enable processing to occur. |
| • | Disables sampling of the PASS-Key® resistance for a time-out period of 3 minutes. |
| • | Does not disarm an armed UTD system. |
| • | The steering column remains in the locked position. |
Conditions for Clearing the DTC
| • | This DTC requires an ignition cycle in order to change from current to history. |
| • | The BCM detects a valid PASS-Key® resistance value on the PASS-Key® input circuit (CKT 1073). |
| • | A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
| • | Use the IPC clearing DTCs feature. |
| • | Use a scan tool. |
Diagnostic Aids
| • | The following conditions may cause an intermittent malfunction: |
| - | There is an intermittent short to ground on CKT 1073. |
| - | There is an intermittent short between CKT 1073 and CKT 1074; the BCM would interpret this as a short to ground condition. |
| - | The PASS-Key® resistor is shorted. |
| • | If the key resistor pellet is incorrect, there will be no BCM outputs to the theft deterrent relay or to the PCM. This state will last about 3 minutes. If a key is inserted, or the ignition is turned ON again before the 3 minute time frame is complete, the timer will reset to 3 minutes. Disconnecting the battery will not clear the timer sequence, but the timer will reset to 3 minutes when the battery power is restored. Even if a proper key is inserted during one of the time periods, the vehicle will not start until the total time period has lapsed. |
| • | If there is a short between CKT 1073 and CKT 1074, or a short to ground on CKT 1073, the vehicle will exhibit a no crank condition. |
| • | If the DTC is a history DTC, the problem may be intermittent. Perform the tests while moving the related wiring, the connectors, and the key. This can often cause the malfunction to appear. Refer to Intermittents and Poor Connections Diagnosis . |
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step checks to see if the PASS-Key® resistor pallet is within the allowable range.
-
This step uses the ignition lock cylinder test in order to determine if the ignition lock cylinder is functioning properly.
-
This step determines if the BCM output voltage to the ignition lock cylinder is within range.
-
This step checks if there is an open or a short to voltage in CKT 1073 or CKT 1074.
-
This step checks for an intermittent malfunction and requests a thorough inspection of any related PASS-Key® circuit wiring and connections.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Were you sent here from the BCM Diagnostic System Check? | -- | ||
Insert the ignition key into the J 35628-A interrogator in order to check the vehicle key code number. Does the J 35628-A interrogator indicate a valid key code in the specified range? | Key Code #1--15 | |||
Perform the lock cylinder test using the J 35628-A interrogator. Refer to Ignition Lock Cylinder Test . Was a problem found? | -- | |||
Is the voltage reading within specifications? | Approx. 5.0 V | |||
Check for a short to ground in CKTs 1073 or 1074. Was a circuit problem found and repaired? | -- | |||
Check the ignition lock cylinder circuit for an intermittent malfunction. Refer to Diagnostic Aids. Was an intermittent malfunction found and repaired? | -- | |||
7 |
Does DTC B2722 set as current? | -- | System OK | |
8 | Replace the ignition lock cylinder. Refer to Ignition Switch Lock Cylinder Replacement in Instrument Panel, Gages and Console. Is the replacement complete? | -- | -- | |
9 | Replace the ignition key. Refer to Programming Replacement Keys, Ignition Cylinder, or Powertrain Control Module . Is the replacement complete? | -- | -- | |
10 |
Is the replacement complete? | -- | -- | |
11 |
Is the repair complete? | -- | -- |
