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 ECM recognizes an emissions-related fault in two consecutive drive cycles, it sends a request to the instrument cluster over the CAN to turn on the malfunction indicator lamp. If an electronic throttle malfunction is recognized, the ECM will send a request to the instrument cluster over the CAN to turn on the electronic power control warning lamp.
The DTCs are sorted by SAE code with the DTC tables consisting of a 5-digit alphanumeric value.
Depending on the 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 information | |||||
| 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 DTCs 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 |
| Evaporative emission canister purge regulator valve | Malfunctioning wiring path or malfunctioning component |
| Circuit open | Malfunction type as next |
-- Switch the ignition off.