Diagnostic Mode 03 - Read DTC Memory
Function
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.
Malfunction Indicator Lamp (MIL) 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: | |||||||
|---|---|---|---|---|---|---|---|
| P x x x x | DTC for drivetrain | ||||||
| U x x x x | DTC for network communication | ||||||
| Norm-Code: | |||||||
|---|---|---|---|---|---|---|---|
| P 0 x x x | DTCs defined by SAE with specified malfunction texts | ||||||
| U 0 x x x | |||||||
| P 1 x x x | additional emission relevant DTCs provided by manufacturer | ||||||
| U 1 x x x | |||||||
| P 2 x x x | DTCs defined by SAE with specified malfunction texts | ||||||
| U 2 x x x | additional emission relevant DTCs provided by manufacturer | ||||||
| P 3 x x x | additional emission relevant DTCs provided by manufacturer | ||||||
| U 3 x x x | |||||||
| System group: | |||||||
| P x 0 x x | Fuel and air mixture and additional emission regulations | ||||||
| U x 0 x x | Network, electrical | ||||||
| P x 1 x x | Fuel and air ratios | ||||||
| U x 1 x x | Network, communication | ||||||
| System group: | |||||||
|---|---|---|---|---|---|---|---|
| P x 2 x x | Fuel and air ratios | ||||||
| U x 2 x x | Network, communication | ||||||
| P x 3 x x | Ignition system | ||||||
| U x 3 x x | Network, software | ||||||
| P x 4 x x | additional exhaust regulation | ||||||
| U x 4 x x | Network, data | ||||||
| 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 | ||||||
Procedure
-- Connect Scan Tool.
-- 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 DIAGNOSTIC TROUBLE CODES ,
- SAE P1xxx-DTCs SAE P1XXX DIAGNOSTIC TROUBLE CODES ,
- SAE P2xxx-DTCs SAE P2XXX DIAGNOSTIC TROUBLE CODES .
- SAE P3xxx-DTCs SAE P3XXX DIAGNOSTIC TROUBLE CODES ,
- SAE U0xxx-DTCs SAE U0XXX DIAGNOSTIC TROUBLE CODES .
The DTC table is sorted by SAE codes.
"Emission" relevant malfunctions are additionally indicated in the instrument cluster via the Malfunction Indicator Lamp (MIL).
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
Erase DTC memory after repairing malfunction DIAGNOSTIC MODE 04 - ERASE DTC MEMORY
Display Example
P0183 Fuel Temperature Sensor A Circuit High
Explanation
- P0183 = SAE diagnostic trouble code (malfunction identification number).
- Fuel Temperature Sensor A = faulty circuit or malfunctioning component.
- Circuit High = malfunction type as text