Diagnostic Trouble Code (DTC)
What is a Diagnostic Trouble Code
The engine control system in your car can – up to a certain point – diagnose problems that may be affecting your vehicle’s emissions or engine performance. When some trouble is detected, the system returns a certain code, indicating the nature of the issue. The code returned is called a Diagnostic Trouble Code or DTC.
How is a DTC formed?
A DTC contains 5 digits, as shown below.
Each digit has a specific meaning.
- P – Powertrain (Engine & Transmission)
- B – Body (Includes A/C & Airbags)
- C – Chassis (Includes ABS)
- U – Network / Bus
- 0 – Generic
- 1 – Vehicle Specific
- 1 – Fuel & Air metering
- 2 – Fuel & Air metering (Injector circuit)
- 3 – Ignition System or Misfire
- 4 – Auxiliary Emission Controls
- 5 – Vehicle Speed Control & Idle Control System
- 6 – Computer Output Circuit
- 7, 8, 9 – Transmission
- A, B, C – Hybrid propulsion
- Fault Description
DTC: U0609 – That’s a Network/Bus issue, generic in nature (not specific to this vehicle). It concerns the computer output circuit. Its classification is “09”, which matches a specific error description that will most likely help you find out what’s wrong with your vehicle.