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Volkswagen New Beetle. Manual - part 1907

PROCEDURE .

DTC P1539/17947: CLUTCH VACUUM VENT SWITCH (F36) - IMPLAUSIBLE SIGNAL

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.

Test Procedure

1. Connect scan tool. See RETRIEVING DIAGNOSTIC TROUBLE CODES . Turn ignition on, engine

off. Following scan tool manufacturer's instructions, check Clutch Vacuum Vent Switch (F36) for DTCs,
this is done in display group 66 when using Scan Tool VAG 1551/1552 or VAS 5051/5052. If no DTCs
are present, go to next step. If DTC(s) are present, repair as necessary. After repairs, erase DTC memory.
Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN
PROCEDURE .

2. Check Clutch Vacuum Vent Switch (F36). Remove trim at clutch pedal to access clutch vacuum vent

switch and disconnect clutch vacuum vent switch harness connector. Using DVOM check resistance at
clutch vacuum vent switch, resistance should be 0 ohms (closed circuit), depress clutch pedal, resistance
should be infinite (open circuit). If Clutch Vacuum Vent Switch (F36) is okay , go to next step. If Clutch
Vacuum Vent Switch (F36) is not okay, replace faulty Clutch Vacuum Vent Switch (F36). After repairs,
erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE
RELEARN PROCEDURE .

3. Using DVOM check Clutch Vacuum Vent Switch (F36) harness connector wiring resistance. Resistance

should be a maximum of 1.5 ohms for each reading. Check Clutch Vacuum Vent Switch (F36) harness
connector wiring for short circuit to one another, short circuit to ground, and short circuit to B+. See
appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING
DIAGRAMS. If wiring is okay, go to next step. If wiring is not okay, repair as necessary. After repairs,
erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE
RELEARN PROCEDURE .

4. If Clutch Vacuum Vent Switch (F36) is okay and wiring is okay, replace faulty ECM. See ENGINE

CONTROL MODULE REMOVAL & INSTALLATION . After repairs, erase DTC memory. Verify
repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN
PROCEDURE .

DTC P1541/17949: FUEL PUMP RELAY (J17) - OPEN CIRCUIT

Test Requirements

Ensure all fuses are okay, battery voltage is at least 11.5 volts. Ensure all electrical accessories are off and A/C

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 .

2003 Volkswagen New Beetle GLS

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

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is off.

Test Procedure

Using DVOM, check power supply and ground to Fuel Pump Relay. See Fig. 38 . See appropriate WIRING
DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. Check resistance of Fuel
Pump Relay wiring. See Fig. 38 . See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in
SYSTEM WIRING DIAGRAMS. Resistance should be a maximum of 1.5 ohms for each reading. Check Fuel
Pump Relay wiring for short circuits to one another, and for short circuits to B+ and ground. See Fig. 38 . See
appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. If
resistance, voltage and ground supply are okay and no short circuits are present, replace faulty Fuel Pump Relay
(J17). If resistance and/or voltage or ground supply are not okay or a short circuit is present, repair as necessary.
Erase DTC memory. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN
PROCEDURE .

DTC P1542/17950, DTC P1543/17951, DTC P1544/17952 & DTC P1545/17953

Code Definition

DTC P1542/17950: Angle Sensor 1 (G187) For Throttle Valve Drive - Implausible Signal

DTC P1543/17951: Angle Sensor 1 (G187) For Throttle Valve Drive - Signal Too Low

DTC P1544/17952: Angle Sensor 1 (G187) For Throttle Valve Drive - Signal Too High

DTC P1545/17953: Throttle Valve Control 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 throttle valve is not damaged or dirty. 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

NOTE:

2003 Volkswagen New Beetle GLS

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

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sound. Ensure no intake or exhaust system leaks exist. Ensure engine coolant temperature is at least 176°F (80°
C).

Test Procedure

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

between terminals No. 3 and 5 on TVCM. See Fig. 20 . Specification is one to 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).

3. 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 to 93 percent (0.15 to 4.65 volts).
Specification for Throttle Valve Drive Angle sensor No. 2 (G188) is 97 to 3 percent (4.90 to 0.15 volts).
If throttle valve drive angle sensor tests are not okay, go to step 6 . If throttle valve drive angle sensor
tests are okay, go to next step.

4. 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.

5. 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 .

6. 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. 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,

NOTE:

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

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

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

TVCM (J338) 6-PIN HARNESS CONNECTOR/VAG TEST BOX SOCKET IDENTIFICATION

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

specified terminals. See TVCM (J338) VOLTAGE SPECIFICATIONS table. See Fig. 33 . 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 .

TVCM (J338) VOLTAGE SPECIFICATIONS

8. 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 .

9. 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 P1546/17954, DTC P1547/17955 & DTC P1548/17956

Code Definition

TVCM 6-Pin Harness Connector Terminal

VAG Test Box Socket

117

118

TVCM 6-Pin Harness Connector Terminals

Voltage

2 & Ground

Minimum 4.5

2 & 6

Minimum 4.5

NOTE:

2003 Volkswagen New Beetle GLS

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

Helpmelearn Repair Manuals

Wednesday, December 14, 2005 8:44:53 AM

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Content .. 1905 1906 1907 1908 ..