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With VW Scan Tool

Output DTM (Diagnostic Test Mode), Checking

The following components are activated by the Output DTM (Diagnostic Test Mode) in the sequence given:
1 Fuel injector 1 (N 30)
2 Fuel injector 2 (N 31)
3 Fuel injector 3 (N 32)
4 Fuel injector 4 (N 33)
5 Fuel injector 5 (N 83)
6 Fuel injector 6 (N 84)
7 Idle Air Control (IAC) valve (N 71)
8 EVAP Canister Purge Regulator valve (N 80)
9 O2S (Oxygen Sensor) relay (J 278)
10 EGR Vacuum Regulator Solenoid valve (N 18) *
11 MAP (Manifold Absolute Pressure valve (N 156) **
12 Secondary Air Injection pump relay (J 299) *
13 Secondary Air Injection solenoid valve (N 112) *

* Use Scan Tool display only if applicable to this vehicle.
** Ignore display. Not applicable to this vehicle.




- connect Scan Tool VAG 1551 using adaptor cable VAG 1551/1 as follows:
- First connect black adaptor cable connector (voltage supply) to black Data Link Connector (DLC).
- display will appear as shown.

Note: Do not connect the white adaptor cable connector if there is no display. Instead, check the voltage supply for scan tool, Refer to VAG 1551 Voltage Supply, Checking. Voltage Supply Checking

- connect white adaptor cable connector to the white/brown Data Link Connector (DLC) 2.
- The blue connector is not used

DLC Location Passat:




Note: The 16 pin DLC connector was phased in during the 1994 model year. If vehicle has the 16 pim DLC, connect VAG 1551 Scan Tool (ST) with VAG 1551/3 adaptor harness.


- switch ON ignition
- press button 1 to select operating mode "Rapid data transfer"
- display will appear as shown

[ Rapid data transfer HELP ]
[ Enter address word XX ]

- press 0 and 1 buttons to select address word 01 "Engine electronics".
- display will appear as shown

[ Rapid data transfer Q ]
[ 01-Engine electronics ]

- press Q button to enter input.
- press -> button.
- display will appear as shown

[ Rapid data transfer HELP ]
[ Select function XX ]

- press 0 and 3 buttons to select function 03 "Output Diagnostic Test Mode".
- display will appear as shown

[ Rapid data transfer Q ]
[ 03 - Output check diagnosis ]

- press Q button to enter input
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ Injector - N 30 ]

To activate fuel injector for cylinder No. 1 (N30)
- manually open throttle valve and then close
- fuel injector No 1 must click
- fuel injectors click very quietly

To activate fuel injectors for cylinder 2 through 6
- reopen and then close the throttle valve once for each injector

To skip an individual check
- press -> button

If one or more injectors does NOT click
- check activation using US 1115 LED tester

To activate IAC (Idle Air Control) valve (N 71)
- press -> nutton
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ Idle Air Control valve (N 71) ]

The IAC valve must switch on and off until the next Output DTM is selected by pressing -> button.

If valve does not operate.
- switch OFF ignition
- disconnect harness connector grom IAC valve
- connect US 1115 LED tester to terminals 1 and 2 of harness connector using jumpers from VW 1594 adaptor kit
- switch ON ignition
- perform previous steps again to activate IAC valve (N 71)
- LED tester must blink

If NO
- check wiring using wiring diagram, repair or replace as necessary

If wiring OK
- replace Engine Control Module (J 220)

To activate EVAP Canister Purge Regulator valve (N 80)
- press -> button
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ EVAP Frequency valve 1 - N 80 ]

Note: The EVAP solenoid valve (behind air cleaner on wheel houing) must click until the next Output DTM (Diagnostic Test Mode) is ended by pressing -> button.
- disconnect hose from soleniod valve (coming from carbon canister)
- attach auxiliary hose to valve
- blow into hose (in direction of throttle housing) while Output DTM (Diagnostic Test Mode) is activated
- valve must open and close

If solenoid valve does NOT click
- disconnect harness connector from valve
- connect US 1115 LED tester between terminals of harness connector using jumpers from VW 1594 adaptor kit
- LED must blink

If YES
- replace EVAP frequency valve (N 80)

If NO
- check wiring using wiring diagram, repair or replace as necessary

If wiring OK
- replace Engine Control Module (J 220)

- To activate O2S (Oxygen Sensor) probe heater (J 278)
- press -> button
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ Oxygen sensor heater relay - J 278 ]

Note: The relay for the O2S (Oxygen Sensor) probe heater (mounted on the fuse/relay panel with a clip) must click until the Output DTM (Diagnostic Test Mode) is ended by pressing the -> button.

If relay does NOT click
- check wiring using wiring diagram

GTo activate EGR Vacuum Regulator Solenoid valve (N 18)
- press -> button
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ EGR frequency valve - N 18 ]

Note: The EGR frequency valve (N 18) must click until by pressing -> button, Output DTM (Output check) ends.

If valve does NOT click
- disconnect harness from valve
- connect US 1115 LED tester to harness connector using jumpers from VW 1594 adaptor kit

If LED tester blinks
- replace EGR frequency valve (N 18)

If LED tester does NOT blink
- check wiring using wiring diagram, repair or replace as necessary

If wiring OK
- replace Engine Control Module (J 220)

- press -> button, display will appear, Ignore display. Not applicable to this vehicle. At present no component has been assigned to this sequence position.

To activate Secondary Air Injection pump relay (J 299)
- press -> button
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ Sec Air Inj pump relay - J 299 ]

Note: The J 299 relay must operate the Secondary Air Injection pump until the next Output DTM is selected by pressing -> button.

If Secondary Air Injection pump motor does NOT run:
- press -> button until the Output Diagnostic Test Mode is completed
- input 06 to select function "End Ouptu" and confirm with Q
- Switch OFF ingnition
- Perform electrical check, Test Step 35 Pinout Values and Diagnostic Parameters or locate short circuit using wiring diagram and correct as necessary.

If an open circuit cannot be located:
- Replace Secondary Air Injection pump relay (J 299) or Motronic Engine Control Module (J 220) as necessary.

To activate Secondary Air Injection solenoid valve (N 112)
- press -> button
- display will appear as shown

[ Output Diagnostic Test Mode -> ]
[ Sec Air Inj solenoid valve - N 112 ]

Note: The N 112 valve must click until the Output DTM is ended by pressing -> button.

If N 112 valve does NOT click
- Switch OFF ingnition
- Perform electrical check, Test Step 35 Pinout Values and Diagnostic Parameters or locate short circuit using wiring diagram and correct as necessary.

If an open circuit cannot be located:
- Replace Secondary Air Injection soleniod valve (N 112) or Motronic Engine Control Module (J 220) as necessary.

- press -> button.
- press 0 and 6 buttons to select function 06 "End output".
- display will appear as shown

[ Rapid data transfer Q ]
[ 06 - End output ]

- press Q button to enter input.