With Manufacturer Scan Tool (VAG)
PURPOSEOutput Diagnostic Test Mode (DTM) is provided to check the mechanical motion and the electrical wiring of certain actuators.
DESCRIPTION
The actuators are checked acoustically or by touch. In some cases, it might be necessary to use an LED tester for the fuel injectors, as the clicking sound from the injectors is very soft and short. Avoid background noise during audible check of the injectors.
When an audible "click" is heard from the actuator being tested, this only confirms that there is electrical current to the actuator and that the component is operating mechanically. The audible noise does not guarantee perfect component operation. Additional testing may be necessary.
This function can only be carried out with the engine OFF (not running) and the ignition switch turned ON. The ignition switch should remain ON throughout entire test. The DTM will be interrupted if the engine is started or if an engine speed pulse is detected.
The following components are activated by the Output DTM in the sequence given:
1. Fuel injector 1 (N30)
2. Fuel injector 2 (N31)
3. Fuel injector 3 (N32)
4. Fuel injector 4 (N33)
5. Fuel injector 5 (N83)
6. Fuel injector 6 (N84)
7. Idle Air Control (IAC) valve (N71)
8. Evaporative Emissions (EVAP) Canister Purge Regulator valve (N80)
9. Heated Oxygen Sensor (HO2S) Relay (J278)
10. EGR Vacuum Regulator Solenoid valve (N18) (two-way valve) *
11. Intake Manifold Change-Over Valve (N156) (ignore display)
12. Secondary Air Injection pump relay (J299) *
13. Secondary Air Injection solenoid valve (N112) *
* Use Scan Tool (ST) display only if applicable to this vehicle.
REQUIREMENTS
^ Throttle Position (TP) Sensor (G69) OK.
CONNECTING
- Connect the VAG 1551 Scan Tool using VAG 1551/3 adapter harness. [1][2]Reading and Clearing Diagnostic Trouble Codes
- Switch ignition ON.
- Press button -1- for "Rapid data transfer" operating mode.
^ Indicated on display:
Rapid data transfer HELP
Select function XX.
- Operate VAG 1551 Scan Tool according to information and instructions on the display.
- Press buttons -0- and -3- for "Output Diagnostic Test Mode" function.
^ Indicated on display:
Rapid data transfer Q
03 - Output Diagnostic Test Mode.
NOTE: If anything else appears in the display, check the VAG 1551 Scan Tool operating instructions.
ACTIVATING CYLINDER # 1 FUEL INJECTOR
- Press -Q- button to confirm input.
^ Indicated on display:
Output Diagnostic Test Mode -->
Fuel injector, cyl. 1 - N30.
- Open throttle valve to Wide Open Throttle (WOT) and close.
NOTE:
- Cyl. 1 Fuel Injector (N30) must click.
- The Fuel Injectors click softly. Avoid other sources of noise in the vicinity when checking.
- To activate cylinders 2 thru 6 Fuel Injectors (N31 - N33, N83, N84), open throttle valve to Wide Open Throttle and close.
- To skip individual tests, Press --> button.
- If one or more of the Fuel Injectors does not click, complete Output Diagnostic Test Mode.
- Switch ignition OFF.
- Carry out additional electrical testing, test steps 12 through 17. [1][2]Pinout Values and Diagnostic Parameters
- Check Fuel Injector actuation (resistance and current).
ACTIVATING IDLE AIR CONTROL VALVE
- Press --> button.
^ Indicated on display:
Output Diagnostic Test Mode -->
Idle Air Control Valve - N71.
NOTE: The IAC Valve must click until switching to the next test in the DTM sequence by pressing the --> button.
- If the IAC Valve does not click:
- Switch ignition OFF.
- Disconnect harness connector from IAC Valve.
- Connect VAG 1527B LED tester to connector terminals -1- and -2- using cables from VAG 1594 adapter kit.
- Switch ignition ON.
- Repeat Output Diagnostic Test Mode - activate Idle Air Control Valve.
NOTE: LED must flash.
- If LED flashes:
- Replace Idle Air Control Valve.
- If LED does not flash:
- Switch ignition OFF.
- Reconnect harness connector to Idle Air Control Valve.
- Carry out electrical testing, test step 27. [1][2]Pinout Values and Diagnostic Parameters
- If necessary replace Motronic Engine Control Module (ECM) (J220).
ACTIVATING EVAPORATIVE EMISSION CANISTER PURGE REGULATOR VALVE
- Press --> button.
^ Indicated on display:
Output Diagnostic Test Mode -->
EVAP Canister Purge Regulator Valve - N80.
NOTE: The EVAP Canister Purge Regulator Valve (on Air Cleaner Housing) must click until the next test in the DTM sequence is selected by pressing the --> button.
- Disconnect hose from EVAP Canister Purge Regulator Valve (hose from EVAP Canister).
- Connect auxiliary hose to valve.
- During Output Diagnostic Test Mode blow into auxiliary hose (in direction of throttle housing).
- Valve solenoid must open and close.
- If the valve solenoid does not click:
- Disconnect two-pin connector from valve and connect US 1527B LED tester across connector terminals using cables from VW 1594 adapter kit.
NOTE: LED must flash.
- If LED flashes:
- Replace EVAP Canister Purge Regulator Valve.
- If LED does not flash:
- Switch ignition OFF.
- Reconnect two-pin connector to EVAP Canister Purge Regulator Valve.
- Carry out electrical testing, test step 18. [1][2]Pinout Values and Diagnostic Parameters
- If necessary replace Motronic Engine Control Module (J220).
ACTIVATING HEATED OXYGEN SENSOR RELAY
- Press --> button.
^ Indicated on display:
Output Diagnostic Test Mode -->
Heated Oxygen Sensor Relay - J278.
NOTE: HO2S Relay (J278) (on auxiliary fuse/relay panel) must click until the next test in the DTM sequence is initiated by pressing the --> button.
- If relay does not click:
- Switch ignition OFF.
- Carry out electrical testing, test step 6, or locate and repair short circuit in wiring. [1][2]Pinout Values and Diagnostic Parameters
- If an open circuit cannot be located:
- Replace Heated Oxygen Sensor Relay or Motronic Engine Control Module (J220) as necessary.
ACTIVATING EGR VACUUM REGULATOR SOLENOID VALVE
- Press-> button.
^ Indicated on display:
Output Diagnostic Test Mode -->
EGR Vacuum Regulator Solenoid Valve - N18.
NOTE: EGR Vacuum Regulator Solenoid Valve (N18) must click.
- If the valve does not click:
- Disconnect two-pin connector from valve and connect US 1527B LED tester across connector terminals using cables VW 1594 adapter kit.
- If LED flashes:
- Replace EGR Vacuum Regulator Solenoid Valve.
- If LED does not flash:
- Switch off ignition.
- Reconnect EGR Valve harness connector.
- Carry out electrical testing, test steps 33 and 34. [1][2]Pinout Values and Diagnostic Parameters
- If necessary, replace Motronic Engine Control Module.
- Press --> button.
^ Indicated on display:
Output Diagnostic Test Mode
Intake Manifold Change-over Valve - N156.
- Ignore display.
- Press --> button.
ACTIVATING SECONDARY AIR INJECTION PUMP RELAY
- Press --> button.
^ Indicated on display:
Output Diagnostic Test Mode
Secondary Air Injection Pump Relay - J299.
NOTE: The Secondary Air Injection Pump Motor (V101) must run until the next test in the DTM sequence is initiated by pressing the --> button.
- If the pump motor does not run:
- Press --> button until the Output Diagnostic Test Mode is completed.
- Press buttons -0- and -6- to select the "End Output" function.
- Press -Q- to confirm input.
- Switch ignition OFF.
- Carry out electrical check, test step 35, or locate and repair short circuit in wiring. [1][2]Pinout Values and Diagnostic Parameters
- If an open circuit cannot be located:
- Replace Secondary Air Injection Pump Relay (J299) or Motronic Engine Control Module as necessary.
ACTIVATING SECONDARY AIR INJECTION SOLENOID VALVE
- Press --> button.
^ Indicated on display:
Output Diagnostic Test Mode
Secondary Air Injection Solenoid Valve - N112.
NOTE: Valve must click.
- If the Valve does not click:
- Switch ignition OFF.
- Carry out electrical check, test step 35, or locate and repair short circuit in wiring. [1][2]Pinout Values and Diagnostic Parameters
- If an open circuit cannot be located:
- Replace Secondary Air Injection Solenoid Valve or Motronic Engine Control Module as necessary.
- If the valve clicks:
- Press --> button.
- Press buttons -0- and -6- to select the "End Output" function.
- Press -Q- to confirm input.
- Switch ignition OFF.