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Volkswagen New Beetle. Manual - part 1847

to INTERMITTENTS in appropriate TROUBLE SHOOTING - NO CODES article. Doing so will help
identify proper system or component to check. See appropriate SYSTEM & COMPONENT TESTING
article for diagnosis of faulty component.

2. After performing DTC checks and repair work, malfunctions may be present in other control modules,

e.g. harness connector disconnected. DTC memories of all control modules must be checked and erased.
See AUTOMATIC TEST SEQUENCE .

Scan Tool VAG 1551/1552 Or VAS 5051/5052

1. Connect scan tool to diagnostic connector located under left side of dashboard. See Fig. 1 . Start engine

and idle.

2. Using Scan Tool VAG 1551/1552 or VAS 5051/5052, start engine and press keys "0" and "1" for address

word "Engine Electronics", press keys "0" and "2" for "Check DTC memory" and enter by pressing "Q"
key. If DTCs are present, record or print DTCs. Press keys "0" and "5" for function "Erase DTC memory"
and enter by pressing "Q" key. Press right arrow key, press keys "0" and "6" for function "End Output"
and enter by pressing "Q" key. To identify DTCs, see DIAGNOSTIC TROUBLE CODE
IDENTIFICATION . Repair as necessary. If no DTCs are present "No DTC recognized" will display.
Press right arrow key, press keys "0" and "6" for function "End Output" and enter by pressing "Q" key. If
a driveability problem exists, refer to INTERMITTENTS in appropriate TROUBLE SHOOTING - NO
CODES article. Doing so will help identify proper system or component to check. See appropriate
SYSTEM & COMPONENT TESTING article for diagnosis of faulty component.

3. After performing DTC checks and repair work, malfunctions may be present in other control modules,

e.g. harness connector disconnected. DTC memories of all control modules must be checked and erased.
For generic scan tools, follow scan tool manufacturer's instruction to check and erase DTCs (this
procedure is called Automatic Test Sequence when using Scan Tool VAG 1551/1552 or VAS
5051/5052). See AUTOMATIC TEST SEQUENCE .

4. If no DTCs are present or after clearing diagnostic trouble codes from all control modules, perform a long

road test. Coolant temperature needs to be greater than 176° F (80° C). Idle, partial throttle, full throttle
and overdrive, must all be attained several times. During test drive, apply full throttle until engine speed
exceeds 3500 RPM. After road test recheck all control modules for DTCs. If DTCs are present, repair as
necessary. Clear codes. See CLEARING DIAGNOSTIC TROUBLE CODES . Verify repairs. Test is
complete.

CLEARING DIAGNOSTIC TROUBLE CODES

Generic Scan Tool

NOTE:

It is recommended that all control modules in the CAN Data Bus are checked for
DTCs before starting and after performing DTC testing and repair work (during
test and assembly work malfunctions can be recognized from other control
modules like e.g. harness connector disconnected). See AUTOMATIC TEST
SEQUENCE .

NOTE:

If ignition is switched off between "Retrieving Diagnostic Trouble Codes" and
"Clearing Diagnostic Trouble Codes" the DTC memory will not be erased, repeat
"Retrieving Diagnostic Trouble Codes" procedure.

2003 Volkswagen New Beetle GLS

2002-2003 ENGINE PERFORMANCE Self-Diagnostics - 1.8L Turbo

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Turn ignition off. Connect scan tool to diagnostic connector located under left side of dashboard. See Fig. 1 .
Follow scan tool manufacturer instructions for clearing DTCs.

Scan Tool VAG 1551/1552 Or VAS 5051/5052

1. Turn ignition off. Connect scan tool to diagnostic connector located under left side of dashboard. See Fig.

1 . DTCs must be read before being erased, see RETRIEVING DIAGNOSTIC TROUBLE CODES .

2. Start engine and press keys "0" and "1" for address word "Engine Electronics", press keys "0" and "5" for

function "Erase DTC memory" and enter by pressing "Q" key. Press keys "0" and "6" for function "End
Output" and enter by pressing "Q" key.

AUTOMATIC TEST SEQUENCE

Generic Scan Tool

Turn ignition off. Connect scan tool to diagnostic connector located under left side of dashboard. See Fig. 1 .
Follow scan tool manufacturer instructions for entering AUTOMATIC TEST SEQUENCE.

Scan Tool VAG 1551/1552 or VAS 5051/5052

1. Turn ignition off. Connect scan tool to diagnostic connector located under left side of dashboard. See Fig.

1 .

2. To enter Automatic Test Sequence, press "0" key 2 times for address word "Automatic test sequence" and

enter by pressing "Q" key. VAG 1551/1552 or VAS 5051/5052 communicates with all control modules in
CAN Data Bus. Any DTCs that are stored will be displayed or "No DTC recognized" will display for
each control module one after another. Automatic test sequence has ended when, "VAG On Board
Diagnostic HELP 1 - Rapid data transfer 2 - Blink code output" is displayed. Erase DTCs, see
CLEARING DIAGNOSTIC TROUBLE CODES . Perform test drive, see TEST DRIVE RELEARN
PROCEDURE . Go to next step.

3. If no DTCs are stored after test drive, press keys "0" and "6" for function "End Output" and enter by

pressing "Q" key. If DTC(s) are stored in a control module in CAN Data Bus, see appropriate DTC table
and diagnostic procedure, (e.g. ABS DTC IDENTIFICATION table, under BRAKES/Anti-Lock/Traction
Control article, if ABS DTC is stored). Repair as necessary. After repairs, erase DTC memory. Verify
repair. Test is complete. Perform test drive, see TEST DRIVE RELEARN PROCEDURE .

TEST DRIVE RELEARN PROCEDURE

NOTE:

When voltage supply to ECM is interrupted or codes have been cleared, ECM
loses all "learned" and/or "basic" values. Serious driveability problems may
occur depending on vehicle mileage. A relearn procedure must be performed.

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2002-2003 ENGINE PERFORMANCE Self-Diagnostics - 1.8L Turbo

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1. If ECM was disconnected during diagnostic procedure or codes have been cleared, go to next step. If

ECM was not disconnected during diagnostic procedure and no codes are present. Perform a test drive.
Recheck for codes (no relearn procedure is necessary).

2. Turn ignition off. Remove test equipment. Reconnect ECM connector. Reconnect all remaining

(disconnected) electrical connectors/components. Go to next step.

Turn ignition on for a minimum of 10 seconds. Turn ignition off. Perform idle check, see IDLE
CHECK . Perform a long road test. Coolant temperature needs to be greater than 176° F (80° C). Idle,
partial throttle, full throttle and overdrive, all must be attained several times. During test drive, apply full
throttle until engine speed exceeds 3500 RPM. Read readiness code. Generate readiness code if
necessary. See READINESS CODE .

READINESS CODE

Readiness Code Description

Readiness code must be generated when ECM memory is cleared, ECM loses battery voltage or is replaced.
Readiness Code appears as an 8-digit display after entering function 15 (display Readiness Code function) on
scan tool (Scan Tool VAG 1551/1552 or VAS 5051/5052). Each of the 8 digits is related to a specific exhaust
emissions related system (not all 8 exhaust emission related systems are checked when ECM generates
Readiness Code, see Fig. 5 and some exhaust emission related systems that are not part of Readiness Code are
checked). During a test sequence OBD system checks function of each emissions relevant exhaust system. OBD
system checks components and generates Readiness Code at regular intervals during normal driving. See
GENERATING READINESS CODE .

Reading Readiness Code

NOTE:

Throttle Valve Control Module (J338) adapts to ECM (J220) automatically if
ignition is switched on for 10 seconds or more without operating
accelerator pedal or starter and ECM recognizes a need for adaptation. No
notification that adaptation was successful will be given when this
happens.

NOTE:

On Beetle, GTI and Jetta, Throttle Valve Control Module (TVCM - J338)
adaptation is part of Readiness Code procedures. TVCM (J338) adaptation can
also be performed by it self, see THROTTLE VALVE CONTROL MODULE .

NOTE:

Manufacturer recommends use of Scan Tool VAG 1551/1552 or VAS 5051/5052.
Not all eight diagnostic functions in Readiness Code are used. See Fig. 5 . It is
recommended that readiness code be read and that readiness code be
generated (if necessary) before performing smog check to guarantee that
emission relevant systems function correctly. Generate readiness code after
performing repairs on exhaust emission systems in order to guarantee that
these systems function correctly. If a malfunction is detected during diagnostic,
malfunction will be entered in DTC memory.

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2002-2003 ENGINE PERFORMANCE Self-Diagnostics - 1.8L Turbo

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Generic Scan Tool - To read readiness code, connect scan tool to DLC. DLC is located left side of steering
column. See Fig. 1 . Follow scan tool manufacturer's instructions and read Readiness Code. See Fig. 5 .
Readiness code should display -0 0 0 0 0 0 0 0-. If readiness code does not display as specified, generate
Readiness Code. See Generating Readiness Code .

Scan Tool VAG 1551/1552 Or VAS 5051/5052 - To read readiness code, connect scan tool to DLC. DLC is
located left side of steering column. See Fig. 1 . Turn ignition on, engine off. Press keys "0" and "1" for address
word "Engine Electronics", press keys "1" and "5" for "Readiness code" and enter by pressing "Q" key. Read
Readiness Code. See Fig. 5 . Readiness Code should display -0 0 0 0 0 0 0 0-. If readiness code does not display
as specified, press right arrow key and generate Readiness Code. See GENERATING READINESS CODE .
If Readiness Code displays as specified, Readiness Code diagnostics are complete and no further Readiness
Code diagnostics are necessary, press keys "0" and "6" for function "End Output" and enter by pressing "Q"
key.

Test Requirements For Generating Readiness Code

Ensure throttle valve is not damaged or dirty. Throttle valve angle must be less than 10 degrees. Ensure all fuses
are okay, battery voltage is at least 11.5 volts and fuel pump relay is okay. Ensure all electrical accessories are
off and A/C is off. Ensure engine is mechanically sound. Ensure no intake or exhaust system leaks exist. Ensure
engine coolant temperature is at least 176°F (80°C). On vehicles with M/T, gear shifter must be in neutral with
parking brake set. On vehicles with A/T, selector lever must be in park or neutral with parking brake set.

Generating Readiness Code

There are two ways to generate Readiness Code:

1. By performing a long road test. Coolant temperature needs to be greater than 176°F (80°C). Idle, partial

throttle, full throttle and overdrive, must all be attained several times. During test drive, apply full throttle
until engine speed exceeds 3500 RPM. This initiates necessary relevant exhaust emission diagnostics and
Readiness Code is then generated when ECM verifies readiness of tested exhaust emission components
(Readiness Code is generated at regular intervals during normal driving). Read readiness code. See
READING READINESS CODE . If Readiness Code displays -0 0 0 0 0 0 0 0-, Readiness Code was
generated on test drive and no further Readiness Code dignostics are necessary.

2. By using scan tool. See GENERATING READINESS CODE (GENERIC SCAN TOOL) or

GENERATING READINESS CODE (SCAN TOOL VAG 1551/1552 OR VAS 5051/5052) .

NOTE:

Before reading readiness code, perform a long road test. Coolant temperature
needs to be greater than 176° F (80° C). Idle, partial throttle, full throttle and
overdrive, must all be attained several times. During test drive, apply full
throttle until engine speed exceeds 3500 RPM. OBD system checks components
and generates Readiness Code at regular intervals during normal driving. See
Generating Readiness Code . Readiness code is erased if DTC memory is
erased or voltage supply to ECM is lost.

WARNING:

When working on vehicles ensure that parking brake is set and
transmission is in park (A/T) or neutral (M/T). For safety during road test,

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2002-2003 ENGINE PERFORMANCE Self-Diagnostics - 1.8L Turbo

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