Common Diagnostic Trouble Codes (DTCs) for ECU and Immobilizer (IMMO) Systems

Question 1

Q17: What does the DTC P0600 indicate?

Answer 1

A17: P0600 indicates a serial communication link malfunction between the ECU and other control modules in the vehicle. It can affect the immobilizer system by disrupting communication between the ECU and the immobilizer or key recognition module.

Question 2

Q18: What does the DTC P0601 indicate?

Answer 2

A18: P0601 indicates an internal control module memory checksum error in the ECU, which may cause the vehicle to fail to start or misfire, as the ECU might not process key recognition or immobilizer data correctly.

Question 3

Q19: What does the DTC P0606 indicate?

Answer 3

A19: P0606 indicates a fault with the Powertrain Control Module (PCM) or ECU processor, which can lead to engine starting issues or improper functioning of the immobilizer system.

Question 4

Q20: What does the DTC P1622 indicate?

Answer 4

A20: P1622 indicates a fault in the immobilizer control module, directly affecting key recognition and potentially preventing the vehicle from starting.

Question 5

Q21: What does the DTC B2780 indicate?

Answer 5

A21: B2780 indicates a transponder communication error, signaling a problem between the immobilizer transponder and the ECU. The vehicle may not recognize the key, leading to a no-start condition.

Question 6

Q22: What does the DTC B2799 indicate?

Answer 6

A22: B2799 indicates a malfunction in the engine immobilizer system, usually due to a failure in key recognition or transponder issues. The vehicle will likely not start as the immobilizer system is not functioning properly.

Question 7

Q23: What does the DTC U0100 indicate?

Answer 7

A23: U0100 indicates that the immobilizer system has lost communication with the ECM/PCM. This can prevent the vehicle from starting due to a lack of communication between the immobilizer and the engine control system.

Question 8

Q24: What does the DTC U1113 indicate?

Answer 8

A24: U1113 indicates a loss of communication with the keyless entry module, which can affect the vehicle’s ability to recognize the key fob, potentially preventing the vehicle from unlocking, locking, or starting.