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Home >> Volkswagen >> 1997 >> Passat Wagon (3A5) L4-1.9L DSL Turbo (1Z) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Scan Tool Testing and Procedures >> Output Diagnostic Test Mode (DTM), (Function 03)

Output Diagnostic Test Mode (DTM), (Function 03)

Special Tools, Testers And Auxiliary Items:
- VAG 1551/1552 Scan Tool using VAG 1551/3 adaptor cable

Test Requirements For Vehicles With A/C:
- Vehicle at room temperature (warmer than +15°C (59°F)
- A/C switched ON
- Lowest temperature setting and highest blower speed selected

Output Diagnostic Test Mode (DTM) actuates the following components in the exact sequence shown:
1. Cold Start Injector N108
2. EGR Vacuum Regulator solenoid valve N18
3. A/C compressor interruption
4. Fuel Cut-off Valve N109
5. Wastegate Bypass Regulator valve N75
6. Glow Plug relay J52
7. Glow Plug Indicator Light K29
8. Relay for pre-heating coolant, low heat output J359
9. Relay for pre-heating coolant, high heat output J360

NOTES:
- DTM components are limited to 30 seconds of activation but they can be stopped earlier by pressing the -> button
- Switch OFF ignition before repeating the Output Diagnostic test.

Work Sequence:
- Connect VAG 1551/1552 Scan Tool
- Start engine and let idle
- Press 0 and 1 buttons to select address word 01 "engine electronics"
Display will appear as shown:

Rapid data transfer HELP
Select function XX

- Operate Scan Tool taking displayed information 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

- Press Q button to enter input
Display will appear as shown:

Output Data Test Mode ->
Cold Start Injector N108

NOTE: As an indicator, activating the Cold-start injector N108 will substantially increase combustion noise due to pre-ignition.

If no change in combustion noise is heard:
- Check Quantity Adjuster N146 control range. Fuel Pump

NOTE: Modulating piston movement sender G149 supplies the control unit with information on the momentary position of the quantity adjuster in the injection pump. The injected fuel quantity is calculated from this information. Sender G149 is a non-contact sensor for measuring the angle of rotation. It is attached to the eccentric shaft of the quantity adjusterter.

- Press -> button
Display will appear as shown

Output Diagnostic Test Mode -->
EGR Vacuum Regulator Solenoid Valve - N18

EGR Vacuum Regulator solenoid valve N18 must click

NOTES:
- EGR valve clicking cannot be heard above engine noises. The valve must be physically touched to detect activation.
- EGR valve piston movement is visible through side slot on valve.

If EGR Valve does not click (activate):
- Check EGR Valve and Mass Air Flow (MAF) sensor and DTC code 00553
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
A/C compressor interuption

NOTES:
- A/C compressor shut-off is checked
- Test step is also applied to vehicles without A/C
- A/C compressor must stop within 5 seconds (visual check) then start and stop approx. every 5 seconds

If A/C compressor not switched OFF:
- Check A/C compressor cut-off, see electrical wiring diagrams
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
Fuel Cut-off Valve N109

Engine must stop

If engine does not stop:
- Switch OFF ignition
- Remove Fuel Cut-off valve N109 and carefully clean off any metal particles or dirt from the component
- Repeat test

If engine will not stop:
- Replace Fuel Cut-off Valve N109
- Continue Output Diagnostic Test Mode (DTM) with engine stopped and ignition switched ON
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
Wastegate Bypass Regulator Valve N75

Wastegate Bypass Regulator valve N75 must click

NOTE: Wastegate Bypass Regulator valve N75 clicking is difficult to hear; activation is best verified by physically touching the valve.

If valve does not click (activate):
- Check Wastegate Bypass Regulator Valve N75 and DTC code 00575
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
Glow Plug relay J52

Relay must click

NOTE: As an indicator, glow plug high amperage draw causes the interior light brightness to fluctuate when switching ON and OFF.

If relay does not click:
- Check Glow Plug Relay J52, see electrical wiring diagrams
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
Glow Plug Indicator Light K29

Glow plug indicator light must blink

If indicator light does not blink:
- Check Glow Plug Indicator Light K29, see electrical wiring diagrams
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
Low Heat Output Relay J359

Relay for preheating coolant, low heat output J359, must click

If relay does not click:
- Check relay J359, see electrical wiring diagrams
- Press -> button
Display will appear as shown:

Output Diagnostic Test Mode -->
High Heat Output Relay J360

Relay for preheating coolant, high heat output J360, must click

If relay does not click:
- Check relay J360, see electrical wiring diagrams
- 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 transfer"
- Press Q button to enter input
- Switch OFF ignition
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