Diagnostic Mode 03 - Read DTC Memory
Diagnostic Mode 03 makes it possible to read emissions-related faults (confirmed DTCs: faults which have activated the MIL) in the ECM and in the TCM.
When the Engine Control Module (ECM) -- recognizes an emission related fault it turns on the Malfunction Indicator Lamp (MIL) -- or if a Electronic Throttle Malfunction is recognized, the Engine Control Module (ECM) -- turns on the Electronic Power Control (EPC) Warning Lamp -- which are both located in the instrument cluster.
The DTC's are sorted by SAE code with the DTC tables consisting of a 5-digit alpha-numeric value.
Depending on scan tool and protocol used, diagnostic mode 03 and the information provided may be referred to by a different name.
The following tables provide a breakdown and explanation of the DTC code.
P-Codes
| Component group | |||||
| P | x | x | x | x | DTC for the drivetrain |
| Norm-Code | |||||
| P | 0 | x | x | x | Trouble codes defined by SAE with specified malfunction texts |
| P | 1 | x | x | x | Additional emission relevant DTCs provided by the manufacturer |
| P | 2 | x | x | x | DTCs defined by SAE with specified texts, from MY 2000 |
| P | 3 | x | x | x | Additional emission relevant DTCs provided by the manufacturer from MY 2000 |
| Component group | |||||
| Repair group | |||||
| P | x | 0 | x | x | Fuel and air mixture and additional emission regulations |
| P | x | 1 | x | x | Fuel and air ratios |
| P | x | 2 | x | x | Fuel and air ratios |
| P | x | 3 | x | x | Ignition system |
| P | x | 4 | x | x | Additional exhaust system |
| P | x | 5 | x | x | Speed and idle control |
| P | x | 6 | x | x | Control module and output signals |
| P | x | 7 | x | x | Transmission |
| P | x | 8 | x | x | Transmission |
| P | x | 9 | x | x | Control modules, input and output signals |
U-Codes
| Component group | |||||
| U | x | x | x | x | DTC for network (CAN bus) |
| Norm-Code | |||||
| U | 0 | x | x | x | Trouble codes defined by SAE with specified malfunction texts |
Procedure
-- Connect the scan tool.
-- Switch the ignition to the "ON" position.
-- Select "Diagnostic Mode 03: Interrogating fault memory ".
-- The stored DTC or DTC's will be displayed on the scan tool screen.
The following table is an example of the DTC information that may be displayed on the scan tool screen:
| Indication example | Explanation |
|---|---|
| P0444 | SAE Diagnostic Trouble Code (DTC) |
| Evaporative Emission (EVAP) Canister Purge Regulator Valve | Malfunctioning wiring path or malfunctioning component |
| Circuit Open | Malfunction type as next |
Refer to the following DTC tables for the diagnostic repair procedure:
-- Switch the ignition off.
-- End of diagnosis.