VAG-COM/VCDS Logging
VAG-COM or VCDS offers a slow way to datalog diagnostic channels on the ECU which can be valuable when diagnosing issues, such as a boost leak. If our support team needs data logs via VCDs, use this guide. It's always preferable to use APR Mobile, where available.
Plug in the OBDII cable, and launch the program with the engine running. Turn off A/C and the traction control system. Roll the windows up. If you just switched octanes, follow our fuel guide. The test will need to be run at wide open throttle in 4th gear from 1,500 RPM to redline unless otherwise specified. Please provide a minimum of 4 tests on the same stretch of road.
Sample Logging Groups
Logging groups will depend on the engine, available values, and several other factors. Always try to group the number in like groups as this will speed up logging sample rates.
The following is an example of an MED 9 ECU found in the 2.0 TFSI.
Boost / Fueling
001-1 Engine Speed
014-3 Misfire Sum
031-1 Lambda, Current Value
054-3 Accelerator Pedal Position
054-4 Throttle Plate Angle
101-3 Injection Timing (Median)
103-1 Current Fuel Pressure
114-4 N75 Duty Cycle
115-3 Boost Pressure (Specified)
115-4 Boost Pressure (Actual)
230-1 Rail Pressure - Specified
230-2 Rail Pressure - Actual
Boost / Timing:
001-1 Engine Speed
003-4 ignition Timing
020-1 Cylinder Ignition Angle Delay (cyl 1)
020-2 Cylinder Ignition Angle Delay (cyl 2)
020-3 Cylinder Ignition Angle Delay (cyl 3)
020-4 Cylinder Ignition Angle Delay (cyl 4)
031-1 Lambda, Current Value
054-3 Accelerator Pedal Position
101-3 Injection Timing (Median)
114-3 Engine Load (actual)
115-4 Boost Pressure (Actual)
230-2 Rail Pressure - Actual
MAF / Load:
001-1 Engine Speed
003-2 Intake Air Mass
031-1 Lambda, Current Value
054-3 Accelerator Pedal Position
054-4 Throttle Plate Angle
101-3 Injection Timing (Median)
103-1 Current Fuel Pressure
114-1 Engine Load (specified)
114-3 Engine Load (actual)
115-3 Boost Pressure (Specified)
115-4 Boost Pressure (Actual)
230-2 Rail Pressure - Actual
Misfire:
001-1 Engine Speed
003-2 Intake Air Mass
015-1 Misfire Cyl 1
015-2 Misfire Cyl 2
015-3 Misfire Cyl 3
016-1 Misfire Cyl 4
054-3 Accelerator Pedal Position
054-4 Throttle Plate Angle
101-3 Injection Timing (Median)
115-3 Boost Pressure (Specified)
115-4 Boost Pressure (Actual)
230-2 Rail Pressure - Actual
Boost / Timing:
003-1 Engine Speed
003-2 Intake Air Mass
003-3 Throttle Angle
003-4 Ignition Timing
020-1 Cylinder Ignition Angle Delay (cyl 1)
020-2 Cylinder Ignition Angle Delay (cyl 2)
020-3 Cylinder Ignition Angle Delay (cyl 3)
020-4 Cylinder Ignition Angle Delay (cyl 4)
031-1 Lambda, Current Value
114-4 N75 Duty Cycle
115-3 Boost Pressure (Specified)
115-4 Boost Pressure (Actual)
The following are general logging blocks found on the 3.0 TFSI (Simos 8.4):
22 Throttle Position
24 Accelerator Position
33 Long Term Fuel Trim Bank 1
34 Long Term Fuel Trim Bank 2
35 Engine SpeedRedline = 7,200 RPMRedline = 7,200 RPM
128 Ambient Pressure
292 Timing Retard Cyl 1
293 Timing Retard Cyl 2
294 Timing Retard Cyl 3
295 Timing Retard Cyl 4
296 Timing Retard Cyl 5
297 Timing Retard Cyl 6
298 Ignition Angle
421 Mass Air Flow
436 Boost Pressure (absolute)
632 Intake Air Temperature
702 Boost Control Valve Angle
The following Examples are for Naturally Aspirated MED9 / MED17 ECUs (2.5L, 3.2L, 3.6L etc)
General:
001-1 Engine Speed
001-2 Coolant Temp
003-2 Intake Air Mass
003-4 Ignition Timing
011-3 Intake Air Temp
031-1 Lambda, Current Value
031-2 Lambda, Specified Value
054-3 Accelerator Pedal Position
054-4 Throttle Plate Angle
101-3 Injection Timing (Median)
114-1 Engine Load (specified)
114-3 Engine Load (actual)
Timing:
001-1 Engine Speed
003-4 Ignition Timing
020-1 Cylinder Ignition Angle Delay (cyl 1)
020-2 Cylinder Ignition Angle Delay (cyl 2)
020-3 Cylinder Ignition Angle Delay (cyl 3)
020-4 Cylinder Ignition Angle Delay (cyl 4)
031-1 Lambda, Current Value
031-2 Lambda, Specified Value
054-3 Accelerator Pedal Position
112-4 Median Exhaust Temp
114-1 Engine Load (specified)
114-3 Engine Load (actual)