Reading Diagnostic Trouble Codes

Diagnostic Modes 01 - 09

Diagnostic Mode 03 - Read DTC Memory

The information provided in Modes 01 through 09 displays the various levels of emission related data that may be monitored, as well as the ability to retrieve and read stored DTC trouble codes, erase stored DTC trouble codes, generate readiness codes, and select the various PIDs and Test-IDs used within the modes to monitor the engine, and emission related component parameters.

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.

Warning light for catalytic converter monitoring (CAT) in instrument cluster lights up for one DTC entry.

Diagnostic Trouble Codes

The DTC always consists of a 5-digit alpha-numeric value with the following meaning:

Component group:

• Pxxxx = DTC for drivetrain.

Norm-Code:

• P0xxx = DTCs defined by SAE with specified malfunction texts.

• P1xxx = Additional emission relevant DTCs provided by manufacturer.

• P2xxx = DTCs defined by SAE with specified malfunction texts.

• P3xxx = Additional emission relevant DTCs provided by manufacturer.

System group:

• Px0xx = Fuel-air mixture and additional emission regulations

• Px1xx = Fuel-air mixture.

• Px2xx = Fuel-air mixture.

• Px3xx = Ignition system.

• Px4xx = Additional emission regulation.

• Px5xx = Speed and idle control.

• Px6xx = Control module and output signals.

• Px7xx = Transmission.

• Px8xx = Transmission.

• Px9xx = Control modules, input and output signals.

Procedure

- Connect diagnostic tester.

- Start engine and let run at idle.

• Only if engine does not start:

- Operate starter for approx. 6 seconds. Do not switch ignition off afterward.

- Under address word 33, select "Diagnostic mode 3: Check DTC memory."

The number of stored malfunctions or "0 malfunctions detected" is displayed.

- End diagnosis and switch ignition off.

- Repair stored malfunctions according to DTC table:

• SAE P0xxx-DTCs => [ SAE P0xxx DTCs ] Testing and Inspection

• SAE P1xxx-DTCs => [ SAE P1xxx DTCs ] Testing and Inspection

• SAE P2xxx-DTCs => [ SAE P2xxx DTCs ] Testing and Inspection

• SAE P3xxx-DTCs => [ SAE P3xxx DTCs ] Testing and Inspection

• SAE U0xxx-DTCs => [ SAE U0xxx DTCs ] Testing and Inspection

• The DTC table is sorted by SAE code.

• "EPC"-relevant malfunctions are also indicated by the warning lamp for Electronic Power Control ("EPC warning lamp") in the instrument cluster.

• In addition, "emission"-relevant malfunctions are indicated in the instrument cluster via the warning light for catalytic converter monitoring (CAT).

• In Diagnostic mode 2, it can be determined at which operating condition a malfunction was detected and stored by the Engine Control Module (ECM) => [ Diagnostic Mode 02 - Read Operating Conditions ] , Diagnostic mode 2: Checking operating conditions.

• Erase DTC memory after repairing malfunction => [ Diagnostic Mode 04 - Erase DTC Memory ] , Diagnostic mode 4: Reset/erase diagnostic data.

Display Example

P0444 Evaporative Emission System Purge Control Valve Circuit Open

Explanation

• P0444 = SAE diagnostic trouble code (malfunction identification number).

• Evaporative Emission System Purge Control Valve = malfunctioning wiring path or malfunctioning component.

• Circuit Open = Malfunction type as text