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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 CTS 🢒 Accessories 🢒 Navigation Systems 🢒 DTC B3055

Circuit Description

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the theft deterrent control module. The theft deterrent control module then compares this value to a value stored in memory, learned key code. If the value is correct the theft deterrent control module sends a random generated number to the transponder, this is called a challenge. Both the transponder and the theft deterrent control module perform a calculation on the challenge, if the calculations match the theft deterrent control module sends the fuel enable password via the class 2 serial data circuit to the engine control module (ECM). If either the transponders unique value or the calculation to the challenge is incorrect the theft deterrent control module will send the fuel disable password to the ECM via the class 2 serial data circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B3055 No Transponder Modulation or No Transponder

Conditions for Running the DTC

The ignition switch is in the ON position and the battery voltage is greater than 9.0 volts.

Condition for Setting the DTC

The theft deterrent control module is unable to measure the ignition key transponder value. This may be due to a damaged or missing transponder, a non Passkey III+ (PK3+) key, or a damaged exciter.

Action Taken When the DTC Sets
    • The vehicle will not start.
    • The theft deterrent control module sends a message via the serial data circuit to the radio to display SERVICE THEFT SYSTEM.
    • The theft deterrent control module sends a message via the serial data circuit to the instrument panel cluster (IPC) to illuminate the SECURITY indicator.

Conditions for Clearing the MIL/DTC
    • The theft deterrent control module clears the current status of the DTC when it senses a valid, memorized, transponder value from the ignition key.
    • The DTC can be cleared by using a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. Verifies the condition for setting DTC B3055 is current.

    2.

  2. The key must be a Passkey III+ (PK3+) transponder key with an operating transponder for the system to work.

    3.

  3. The only method to confirm whether the transponder in the key or the theft deterrent control module is malfunctioning is to try a alternative component in the system. The vehicle was delivered with 2 keys.

    4.

  4. The possibility is unlikely that more than one key will be defective. If all keys do not work, the theft deterrent control module must be malfunctioning.

    5.

  5. If a new key must be tried, the key must have the proper mechanical cut and the theft deterrent control module must "learn" the transponder value.

    6.

  6. If only one key was available for the vehicle and the replacement key does not work, the theft deterrent control module must be malfunctioning.

Step

Action

Yes

No

Schematic Reference: Theft Deterrent System Schematics

Connector End View Reference: Theft Deterrent System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Is DTC B3055 set as a current code?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Inspect the vehicle's key for damage to the molded head and for PK3+ embossed on the shank.

Is the head of the key damaged or missing the PK3+ embossing?

Go to Step 7

Go to Step 4

4

Are more than one of the vehicles keys available?

Go to Step 5

Go to Step 7

5

  1. Attempt to start the vehicle using all of the vehicle's available keys.
  2. Using a scan tool, observe for any theft deterrent control module DTCs.

Do any of the available keys start the vehicle?

Go to Step 6

Go to Step 9

6

Do all of the available keys cause DTC B3055 to set?

Go to Step 9

Go to Step 7

7

Important: Two learned master keys are required to perform the Adding Keys procedure on export vehicles with option code (UA2 OR Z49)

  1. Replace the damaged/inoperative/suspect key.
  2. Copy the mechanical cut of the available key on a passkey III+ (PK3+) replacement key.
  3. Perform the Adding Keys procedure if a learned master key is available. Refer to Adding Keys . If a learned master key is not available . Refer to Replacing Keys .

Did you complete the replacement?

Go to Step 9

--

8

Does the replacement key cause DTC B3055 to set?

Go to Step 9

Go to Step 10

9

Important: If a 10 Minute or 30 Minute Re-Learn Procedure is perform, all keys not learned at that time will be erased and will not be recognized. Perform the Adding Keys procedure on all keys or instruct the customer how to perform the Adding Keys procedure. Refer to Adding Keys .

Replace the theft deterrent control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming.

Did you complete the replacement?

Go to Step 10

--

10
  1. Use a scan tool in order to clear the DTCs.
  2. Attempt to start the vehicle.

Does the DTC reset?

Go to Step 2

System OK