Content .. 1838 1839 1840 1841 ..

Volkswagen New Beetle. Manual - part 1840

DVOM, check resistance between TVCM (J338) 6-pin harness connector and test box sockets. See
TVCM (J338) 6-PIN HARNESS CONNECTOR/VAG TEST BOX SOCKET IDENTIFICATION
table. Record resistance readings. Resistance should be a maximum of 1.5 ohms for each reading. Check
wiring in TVCM (J338) 6-pin harness connector for short circuits to one another, and for short circuits to
B+ and ground. If resistance measurements are okay and no short circuits exist, go to next step. If any
resistance measurement is not okay, or a short circuit exists, repair circuit(s) as necessary. After repairs,
erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE
RELEARN PROCEDURE .

8. Turn ignition on. Using DVOM, measure voltage between TVCM (J338) 6-pin harness connector

specified terminals. See TVCM (J338) VOLTAGE SPECIFICATIONS table. See Fig. 20 . Record
voltage readings. If voltage readings are not okay, go to next step. If voltage readings are okay, resistance
measurements are okay and no short circuits exist, replace faulty TVCM. After repairs, erase DTC
memory. Verify repair. Test is complete. Adapt TVCM (J338) to ECM (J220). See THROTTLE
VALVE CONTROL MODULE (J338) . For vehicles with A/T, adapt TVCM (J338) to Transmission
Control Module (J217). See A/T BASIC SETTING . On all models, perform ECM relearn procedure.
See TEST DRIVE RELEARN PROCEDURE .

9. Check ECM voltage supply. See ECM GROUND & VOLTAGE SUPPLY under ECM (J220) - ME

SFI CONTROL MODULE. If ECM ground circuits and ECM voltage supply are okay, go to next step. If
ECM ground circuits and/or ECM voltage supply are not okay, repair as necessary. After repairs, erase
DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE
RELEARN PROCEDURE .

10. Replace faulty ECM. See ENGINE CONTROL MODULE REMOVAL & INSTALLATION . Erase

DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE
RELEARN PROCEDURE .

DTC P1559/17967: THROTTLE VALVE CONTROL MODULE (J338) - MALFUNCTION IN BASIC
SETTING

Test Requirements

Ensure battery is okay. 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 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.

Throttle Valve Control Module Adaption

TVCM (J338) adaptation must be performed when voltage supply to TVCM (J338) or ECM is lost. TVCM
(J338) adaptation occurs:

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.

When initiated through diagnostic function 04 - BASIC SETTING in display group 060, (VAG
1551/1552 or VAS 5051/5052). Follow scan tool manufacturer's instructions.

2003 Volkswagen New Beetle GLS

2001-2003 ENGINE PERFORMANCE Self-Diagnostics - 2.0L - Beetle, Golf & Jetta (Engine Codes AVH & AZG)

Helpmelearn Repair Manuals

Wednesday, December 14, 2005 8:50:00 AM

Page 160

1. Connect scan tool to DLC. DLC is located on left side of steering column. Using scan tool check and

clear any DTCs in memory. See RETRIEVING DIAGNOSTIC TROUBLE CODES .

Using scan tool, follow scan tool manufacturer's instructions for TVCM (J338) adaptation. If you are
using Scan Tool VAG 1551/1552 or VAS 5051/5052, from selection 1 enter diagnostic function 04 -
BASIC SETTING. Follow scan tool instructions to enter diagnostic function 04 - BASIC SETTING
function. Enter DISPLAY GROUP 060. Follow scan tool instructions for TVCM (J338) adaptation.

DTC P1564/17972: THROTTLE VALVE CONTROL MODULE (J338) - VOLTAGE TOO LOW
DURING BASIC SETTING

Test Requirements

Throttle Valve Control Module Adaption

TVCM (J338) adaptation must be performed when voltage supply to TVCM (J338) or ECM is lost. TVCM
(J338) adaptation occurs:

When initiated through diagnostic function 04 - BASIC SETTING in display group 060, (VAG
1551/1552 or VAS 5051/5052). Follow scan tool manufacturer's instructions.

Check charging system and battery condition. Repair as necessary. Go to next step.

NOTE:

Engine will not start during automatic adaptation. Ignition must remain on
(engine off) for entire adaptation procedure. Ensure coolant temperature and
intake air temperature are between 50-194° F (10-90° C). Battery voltage a
minimum of 11.5 volts.

NOTE:

ECM will abort adaptation if; throttle valve cannot be closed completely
(e.g. dirty throttle body, distorted throttle body or lose throttle body bolts),
battery voltage is too low, engine is started or accelerator pedal is pressed
during adaptation.

NOTE:

Engine will not start during automatic adaptation. Ignition must remain on
(engine off) for entire adaptation procedure. Ensure coolant temperature
and intake air temperature are between 50-194° F (10-90° C). Battery
voltage a minimum of 11.5 volts.

2003 Volkswagen New Beetle GLS

2001-2003 ENGINE PERFORMANCE Self-Diagnostics - 2.0L - Beetle, Golf & Jetta (Engine Codes AVH & AZG)

Helpmelearn Repair Manuals

Wednesday, December 14, 2005 8:50:00 AM

Page 161

2. Connect scan tool to DLC. DLC is located on left side of steering column. Using scan tool check and

clear any DTCs in memory. See RETRIEVING DIAGNOSTIC TROUBLE CODES .

DTC P1568/17976: THROTTLE VALVE CONTROL MODULE (J338) - MECHANICAL
MALFUNCTION

Circuit/Component Description

Throttle Valve Control Module (TVCM - J338) is located on throttle body. Throttle valve drive angle sensors
and are located in TVCM (J338). ECM monitors throttle valve drive angle sensors for throttle valve position.
ECM calculates throttle position based on percentage values sent by throttle valve drive angle sensors.

Throttle valve drive angle sensors run in opposite directions of each other. Throttle Valve Drive Angle sensor
No. 1 (G187) displays throttle positions from 3-97 percent. Throttle Valve Drive Angle sensor No. 2 (G188)
displays throttle positions from 97-3 percent. Throttle Valve Drive Angle sensor No. 1 (G187) ranges from 3-93
percent (0.15-4.65 volts), the larger the throttle opening the higher the percentage (voltage) reading. Throttle
Valve Drive Angle sensor No. 2 (G188) ranges from 97-3 percent (4.90-0.15 volts), the larger the throttle
opening the smaller the percentage (voltage) reading. When the engine is running (under load) the ECM can
operate throttle valve independently of driver input.

Test Requirements

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.

Test Procedure

NOTE:

ECM will abort adaptation if; throttle valve cannot be closed completely
(e.g.: dirty throttle body, distorted throttle body or lose throttle body
bolts), battery voltage is too low, engine is started or accelerator pedal is
pressed during adaptation.

NOTE:

If a test ends with ECM replacement, before replacing ECM be certain that, all
wiring, power and ground supplies are okay. See ENGINE PERFORMANCE in
SYSTEM WIRING DIAGRAMS article in ELECTRICAL and ECM GROUND &
VOLTAGE SUPPLY .

NOTE:

Test ranges for throttle valve drive angle sensors may not fully display on scan

2003 Volkswagen New Beetle GLS

2001-2003 ENGINE PERFORMANCE Self-Diagnostics - 2.0L - Beetle, Golf & Jetta (Engine Codes AVH & AZG)

Helpmelearn Repair Manuals

Wednesday, December 14, 2005 8:50:00 AM

Page 162

1. Check throttle body for residue/dirt buildup. Clean throttle body as necessary. Check throttle body for

damage. Repair or replace throttle body as necessary. If throttle body was cleaned, repaired or replaced,
erase DTC memory. Verify repair. Test is complete. Adapt TVCM (J338) to ECM (J220). See
THROTTLE VALVE CONTROL MODULE (J338) . Perform ECM relearn procedure. See TEST
DRIVE RELEARN PROCEDURE . If DTC resets on test drive, go to next step.

2. Turn ignition off. Disconnect TVCM (J338) 6-pin harness connector. Using DVOM check resistance

between terminals No. 3 and 5 on TVCM. See Fig. 19Fig. 20 . Specification is 1-5 ohms. If resistance is
okay, go to next step. If resistance is not okay, replace faulty TVCM. Erase DTC memory. Verify repair.
Test is complete. Adapt TVCM (J338) to ECM (J220). See THROTTLE VALVE CONTROL
MODULE (J338) . For vehicles with A/T, adapt TVCM (J338) to Transmission Control Module (J217).
See A/T BASIC SETTING . On all models, perform ECM relearn procedure. See TEST DRIVE
RELEARN PROCEDURE .

Connect scan tool. See RETRIEVING DIAGNOSTIC TROUBLE CODES . Turn ignition on, engine
off. Following scan tool manufacturer's instructions, observe percentage reading for Throttle Valve Drive
Angle sensor No. 1 (G187) and Throttle Valve Drive Angle sensor No. 2 (G188) at idle stop.
Specification for Throttle Valve Drive Angle sensor No. 1 (G187) is 3-16 percent. Specification for
Throttle Valve Drive Angle sensor No. 2 (G188) is 97-82 percent.

4. Operate accelerator pedal slowly to Wide Open Throttle and observe percentage (voltage) readings for

Throttle Valve Drive Angle sensor No. 1 (G187) and Throttle Valve Drive Angle sensor No. 2 (G188).
Specification for Throttle Valve Drive Angle sensor No. 1 (G187) is 3-93 percent (0.15-4.65 volts).
Specification for Throttle Valve Drive Angle sensor No. 2 (G188) is 97-3 percent (4.90-0.15 volts). If
throttle valve drive angle sensor tests are not okay, go to step 7 . If throttle valve drive angle sensor tests
are okay, go to next step.

5. Check APP sensors. See DTC P0226/16610: ACCELERATOR PEDAL POSITION SENSOR 1

(G79) ACCELERATOR PEDAL POSITION SENSOR 2 (G185), IMPLAUSIBLE SIGNAL . If
APP sensors are not okay, go to next step. If APP sensors are okay. Erase DTC memory. Perform ECM
relearn procedure. See TEST DRIVE RELEARN PROCEDURE . If code did not return on test drive,
test is complete.

6. Replace APP sensors. Erase DTC memory. Verify repair. Test is complete. For vehicles with A/T, adapt

APP sensors to Transmission Control Module (J217). See A/T BASIC SETTING . On all models,
perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .

7. Turn ignition off. Disconnect ECM harness connector. Leave ECM disconnected from test box. Connect

Test Box (VAG 1598/31) to ECM harness connector. See CONNECTING VAG TEST BOX . Using
DVOM, check resistance between TVCM (J338) 6-pin harness connector and test box sockets. See
TVCM (J338) 6-PIN HARNESS CONNECTOR/VAG TEST BOX SOCKET IDENTIFICATION
table. Record resistance readings.

8. Resistance should be a maximum of 1.5 ohms for each reading. Check wiring in TVCM (J338) 6-pin

harness connector for short circuits to one another, and for short circuits to B+ and ground. If resistance

tool. No idle specifications for throttle valve drive angle sensors are given by
manufacturer.

NOTE:

If TVCM (J338) is replaced it must be adapted to the ECM and A/T control
module (if equipped).

2003 Volkswagen New Beetle GLS

2001-2003 ENGINE PERFORMANCE Self-Diagnostics - 2.0L - Beetle, Golf & Jetta (Engine Codes AVH & AZG)

Helpmelearn Repair Manuals

Wednesday, December 14, 2005 8:50:00 AM

Page 163

Content .. 1838 1839 1840 1841 ..