Work sequence

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1999 Volkswagen Jetta, 1998 Volkswagen Jetta, 1997 Volkswagen Passat, 1997 Volkswagen Jetta, and 1996 Volkswagen Passat. However, it is still accessible from the selected car via links, so may be relevant.

Start engine and let idle.
Connect VAG1551 or VAG1552 scan tool, see VAG1551 SCAN TOOL (ST), CONNECTING .
Press buttons -0- and -1- to select the "Engine Electronics" address word 01.

Indicated on display

Fig 1: Scan Tool Display - Checking Output Diagnostic Test Mode (1 Of 9)

Operate scan tool according to directions on display.
Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.

Indicated on display

Fig 2: Scan Tool Display - Checking Output Diagnostic Test Mode (2 Of 9)

Press -Q- button to confirm input.

Indicated on display

Fig 3: Scan Tool Display - Checking Output Diagnostic Test Mode (3 Of 9)

NOTE: Activating the cold start injector can influence combustion noise considerably (pre-ignition).

If there is no change in combustion noise:

Check injection adjuster control range, see QUANTITY ADJUSTER CONTROL RANGE, CHECKING .
Press ==> button.

Indicated on display

Fig 4: Scan Tool Display - Checking Output Diagnostic Test Mode (4 Of 9)

EGR vacuum regulator solenoid valve must click

NOTE: Because of engine noise levels, the clicking valve cannot be heard; it must therefore be touched to verify operation.

If valve does not click:

Check Exhaust Gas Recirculation (EGR) and Mass Air Flow (MAF) sensor function, see EXHAUST GAS RECIRCULATION (EGR) AND MASS AIR FLOW (MAF) SENSOR FUNCTIONS, CHECKING .
Press ==> button.

Indicated on display

Fig 5: Scan Tool Display - Checking Output Diagnostic Test Mode (5 Of 9)

NOTE:

A/C compressor shut-off is checked
The test step is also recalled on vehicles without A/C.
The A/C compressor must stop within 5 secs. (visual check) then start approx. every 5 secs. and stop.

If compressor is not switched off:

Check A/C compressor cut-off. See AIR CONDITIONING .

Press ==> button.

Indicated on display

Fig 6: Scan Tool Display - Checking Output Diagnostic Test Mode (6 Of 9)

Engine must stop running

If not:

Switch ignition off.
Unscrew fuel cut-off valve -N109- and remove any metal particles or dirt, see DIESEL DIRECT FUEL INJECTION (DFI) SYSTEM COMPONENTS, OVERVIEW , item 14.
Repeat output Diagnostic Test Mode (DTM).

If engine will not stop running:

Replace fuel cut-off valve -N109-.
Continue output DTM with engine stopped and ignition switched on.
Press ==> button.

Indicated on display

Fig 7: Scan Tool Display - Checking Output Diagnostic Test Mode (7 Of 9)

Wastegate bypass regulator valve must click

NOTE: Because of engine noise levels, the clicking valve cannot be heard; it must therefore be touched to verify operation.

If valve does not click:

Check wastegate bypass regulator valve -N75-, see WASTEGATE BYPASS REGULATOR VALVE, ELECTRICAL CHECKS .
Press ==> button.

Indicated on display

Fig 8: Scan Tool Display - Checking Output Diagnostic Test Mode (8 Of 9)

Glow plug relay must click

NOTE:

The production number "180" must be on the reverse side of the relay.
Relay switching can also be verified by watching the interior light as it becomes brighter and darker due to high glow plug power consumption.

If the relay does not click:

Check glow plug relay.

If relay clicks:

Disconnect Engine Coolant Temperature Sensor -G62-.
Switch ignition ON.
Wait 20 seconds for Glow Plug Indicator Light -K29- to go OFF.
Check DTC memory, see CHECK DTC MEMORY (SCAN TOOL FUNCTION 02) .

If only DTC 00522 appears, Glow Plug Relay -J52- is OK.

Check for malfunction in DTC memory and eliminate if necessary, see CHECK DTC MEMORY (SCAN TOOL FUNCTION 02) .
Continue test.

If DTC 01050 also appears, Glow Plug Relay - J52- is faulty.

Replace Glow Plug Relay -J52-.

Check DTC memory, see CHECK DTC MEMORY (SCAN TOOL FUNCTION 02) .
Set Readiness code, see READINESS CODE, SETTING (M.Y. 1997) .
Press ==> button.

Indicated on display

Fig 9: Scan Tool Display - Checking Output Diagnostic Test Mode (9 Of 9)

Glow plug indicator light must blink

If the glow plug indicator light does not blink:

Connect VAG1598/18 test box to ECM harness connector, see WIRING AND COMPONENT CHECKS, USING VAG1598/18 TEST BOX .
Connect socket 48 (indicator light wiring) with socket 46 (Ground)
Switch ignition on.

Fig 10: Connecting VAG1598/18 Test Box To ECM Harness Connector