Output Diagnostic Test Mode (DTM) (Function 03)
Output Diagnostic Test Mode (DTM), performing
Performing an Output DTM activates the following DTM components in sequence as listed:
1. Fuel Injector, cylinder 1 N30
2. Fuel Injector, cylinder 2 N31
3. Fuel Injector, cylinder 3 N32
4. Fuel Injector, cylinder 4 N33
5. EVAP canister purge regulator valve 1 N80
6. Wastegate Bypass Regulator Valve N75
Special tools, testers, measuring instruments and auxiliary items required
- VAG 1551/1552 Scan Tool using VAG 1551/3 adaptor cable
- VAG 1598/22 Test Box
- VW 1594 Adaptor kit
- Fluke 83 Multimeter
- VAG 1527 B Voltage tester
- Wiring Diagram
Test conditions
- Fuses 28,29,32 and 34 OK
NOTE:
- Output Diagnostic Test Mode (DTM) can only be performed with the engine not running and the ignition switched ON.
- Output DTM will be terminated if the engine is started or if a rotational impulse is recognized.
- During the Output DTM the DTM components will be activated until advanced to the next DTM component by pressing the -> button.
- Output DTM components are checked acoustically or by feel.
- If it is necessary to repeat the Output DTM, without first running the engine briefly, switch the ignition OFF for approx. 2 seconds.
- The fuel pump will run during the complete Output DTM.
- The Output DTM will be aborted after 70 minutes.
Work sequence
- Connect VAG 1551/1552 Scan Tool.
- Switch ON ignition
- Press 0 and 1 buttons to select Address Word 01 "Engine electronics", [1][2][3]Reading and Clearing Diagnostic Trouble Codes
Display will appear as shown
Rapid data transfer HELP
Select Function XX
- Operate Scan Tool taking displayed data into account
- Press 0 and 3 buttons to select Function 03: "Output Diagnostic Test Mode".
Display will appear as shown
Rapid data transfer Q
03 Output Diagnostic Test Mode
Display will appear as shown
Fuel injectors (N30 to N33), activating
- Press Q button to enter input.
Display will appear as shown
Output Diagnostic Test Mode ->
Injector cylinder 1 - N30
NOTE: The fuel pump must run and flow must be distinctly audible at the fuel pressure regulator. If the fuel pump does not run, check the activation.
- Open throttle
- As soon as the Closed Throttle Position switch opens, number 1 Cyl. injector will click 5 times.
- Press -> button each time you wish to advance to next injector
NOTE: Advancing is also possible without testing each individual injector.
- All injectors can be checked sequentially in this manner.
If one of the injectors is not activated (does not click):
- Check injectors, Refer to "Fuel Injector" under "Fuel Delivery and Air Induction", Testing and Inspection.
EVAP canister purge regulator valve 1, activating
- Press -> button.
Display will appear as shown
Output Diagnostic Test Mode ->
EVAP canister purge regulator valve 1 N80
NOTE: The EVAP canister purge regulator valve 1 (on Air Cleaner housing) must click until the next DTM component is activated by pressing the -> button.
If valve clicks but malfunction is still suspected (valve does not open or close):
- Disconnect hose from EVAP canister purge regulator valve 1
- Connect an auxiliary hose to the vacant valve connection.
- Blow into auxiliary hose during Output DTM (in direction of Throttle Body Control Module).
- Valve must open and close
If solenoid valve does NOT click
- Disconnect harness connector -1- from EVAP canister purge regulator valve -2- and connect VAG 1527 B voltage tester to harness connector using jumper wires from VW 1594 adaptor kit
- LED tester must flash
If LED flashes:
- Proceed with Output DTM until completed.
- Switch OFF ignition.
- Replace EVAP canister purge regulator valve N80.
If LED does not flash:
- Proceed with Output DTM until completed.
- Switch OFF ignition.
- Connect VAG 1598/22 Test Box to ECM wiring harness.
- Check wiring for open circuit between Test Box socket 15 and 2-pin connector terminal 2 using Wiring Diagram.
- Wire resistance: 1.5 Ohms maximum
- Also check wiring for short to B+ and Ground.
- Specification: Infinity Ohms
- Check wiring for open circuit between 2-pin harness connector terminal 1 and fuel pump relay J17 using Wiring Diagram.
- Wire resistance: max. 1.5 Ohms
If wiring OK
- Replace ECM.
Wastegate Bypass Regulator valve N75, activating
- Press -> button.
Display will appear as shown
Output Diagnostic Test Mode ->
Wastegate Bypass Regulator valve -N75
- Valve must click.
NOTE: It is difficult to hear the valve click and is best checked by touch.
If valve does not "click"
- Disconnect harness connector -1- from valve -2- and connect VAG 1527 B Voltage tester between terminals of harness connector using jumper wires from VW 1594 adaptor kit
- LED tester must flash
If LED flashes
- Replace valve N75.
If LED does not flash
- Proceed with Output Diagnostic Test Mode until completed.
- Switch OFF ignition.
- Connect VAG 1598/22 Test Box to ECM wiring harness.
- Check wiring for open circuit between Test Box socket 64 and 2-pin harness connector terminal 2 using Wiring Diagram.
- Wire resistance: 1.5 Ohms maximum
- Additionally check wire for short to battery positive and Ground.
- Specification: Infinity Ohms
- Check wiring for open circuit between 2-pin harness connector terminal 1 and fuel pump relay J17 using Wiring Diagram.
- Wire resistance: max. 1.5 Ohms
If wiring OK
- Replace ECM.
- Press -> button.
Display will appear as shown
Rapid data transfer HELP
Select Function XX
- Press 0 and 6 buttons to select Function 06 "End data output"
- Press Q button to enter input
- Switch OFF ignition.
NOTE: After Output Diagnostic Test Mode completion, switch OFF the ignition. If it is NOT switched OFF before attempting to start, the engine will not start because the fuel injectors and ignition coils will not be activated.