Volkswagen New Beetle. Manual - part 1873

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).  

Test Procedure - Charge Air Pressure Sensor 

1. Verify battery voltage is a minimum of 11.5 volts and all fuses are okay. Go to next step.  

2. Disconnect Charge Air Pressure sensor 4-pin harness connector. See COMPONENT LOCATIONS . 

Turn ignition on. Using DVOM measure voltage between terminals No. 1 and 3 of Charge Air Pressure 
sensor 4-pin harness connector. See Fig. 25 . Voltage should be a minimum of 4.5 volts. Turn ignition 
off. If readings are okay, go to next step (additional testing is needed). If readings are not okay, go to next 
step.  

3. 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 the following Charge Air Pressure sensor harness connector terminals and test box 
sockets. See Fig. 25 . 

z

Charge Air Pressure sensor harness connector terminal No. 1 and test box socket No. 108.  

z

Charge Air Pressure sensor harness connector terminal No. 3 and test box socket No. 98.  

z

Charge Air Pressure sensor harness connector terminal No. 4 and test box socket No. 101.  

Resistance should be a maximum of 1.5 ohms for each reading. Check wiring in Charge Air Pressure 
sensor harness connector 4-pin connector for short circuits to one another. Go to next step.  

4. If Charge Air Pressure sensor harness connector circuits are okay and 4.5 volts minimum is present 

between terminals No. 1 and 3 of Charge Air Pressure sensor 4-pin harness connector, go to next step. If 
Charge Air Pressure sensor harness connector circuits are okay, but no voltage is present between 
terminals No. 1 and 3 of Charge Air Pressure sensor 4-pin harness connector, replace ECM. See 
ENGINE CONTROL MODULE REMOVAL & INSTALLATION . Erase DTC memory. Verify 
repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE .  

5. Leave ECM harness connected to Test Box (VAG 1598/31) and connect ECM to Test Box (VAG 

1598/31). See CONNECTING VAG TEST BOX . Start engine and idle. Using DVOM, check voltage 
between test box sockets No. 101 and 108. For all models except Beetle (engine code AWV) voltage 
should be 1.8-2.0 volts at idle. For Beetle (engine code AWV) voltage should be 0.4-0.5 volts at idle. 
Observe DVOM and briefly accelerate from idle to wide open throttle. For all models, voltage reading 
should be 2.0-3.0 volts. If voltage readings are okay, Charge Air Pressure sensor is okay. Erase DTC 
memory. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE . If voltage readings are not okay, replace faulty Charge Air Pressure sensor. Erase DTC 
memory. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE .  

DTC P0237/16621 & DTC P0238/16622 

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 

 

2003 Volkswagen New Beetle GLS 

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

  

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Code Definition 

z

DTC P0237/16621: Charge Air Pressure Sensor (G31) - Signal Too Low  

z

DTC P0238/16622: Charge Air Pressure Sensor (G31) - Signal Too High  

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).  

Test Procedure - Charge Air Pressure Sensor 

1. Verify battery voltage is a minimum of 11.5 volts and all fuses are okay. Go to next step.  

2. Disconnect Charge Air Pressure sensor 4-pin harness connector. See COMPONENT LOCATIONS . 

Using DVOM measure voltage between terminals No. 1 and 3 of Charge Air Pressure sensor 4-pin 
harness connector. See Fig. 25 . Voltage should be a minimum of 4.5 volts. Turn ignition off. If readings 
are okay, go to next step. If readings are not okay, go to next step.  

3. 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 the following Charge Air Pressure sensor harness connector terminals and test box 
sockets. See Fig. 25 . 

z

Charge Air Pressure sensor harness connector terminal No. 1 and test box socket No. 108.  

z

Charge Air Pressure sensor harness connector terminal No. 3 and test box socket No. 98.  

z

Charge Air Pressure sensor harness connector terminal No. 4 and test box socket No. 101.  

Resistance should be a maximum of 1.5 ohms for each reading. Check wiring in Charge Air Pressure 
sensor harness connector 4-pin connector for short circuits to one another. Go to next step.  

4. If Charge Air Pressure sensor harness connector circuits are okay and 4.5 volts minimum is present 

between terminals No. 1 and 3 of Charge Air Pressure sensor 4-pin harness connector, go to next step. If 
Charge Air Pressure sensor harness connector circuits are okay, but no voltage is present between 
terminals No. 1 and 3 of Charge Air Pressure sensor 4-pin harness connector, replace ECM. See 
ENGINE CONTROL MODULE REMOVAL & INSTALLATION . Erase DTC memory. Verify 
repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE .  

5. Leave ECM harness connected to Test Box (VAG 1598/31) and connect ECM to Test Box (VAG 

1598/31). See CONNECTING VAG TEST BOX . Start engine and idle. Using DVOM, check voltage 
between test box sockets No. 101 and 108. For all models except Beetle (engine code AWV) voltage 
should be 1.8-2.0 volts at idle. For Beetle (engine code AWV) voltage should be 0.4-0.5 volts at idle. 
Observe DVOM and briefly accelerate from idle to wide open throttle. For all models, voltage reading 
should be 2.0-3.0 volts. If voltage readings are okay, Charge Air Pressure sensor is okay. Erase DTC 
memory. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE . If voltage readings are not okay, replace faulty Charge Air Pressure sensor. Erase DTC 

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

DTC P0243/16627, DTC P0245/16629 & DTC P0246/16630 

Code Definition 

z

DTC P0243/16627: Wastegate By-Pass Regulator Valve (N75) - Open/Short To Ground  

z

DTC P0245/16629: Wastegate By-Pass Regulator Valve (N75) - Short To Ground  

z

DTC P0246/16630: Wastegate By-Pass Regulator Valve (N75) - Short To B+  

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).  

Test Procedure 

1. Turn ignition off. Locate wastegate by-pass regulator valve. See COMPONENT LOCATIONS . Check 

hoses to wastegate by-pass regulator valve (N75). If hoses are okay, go to next step. If hoses are not okay, 
repair as necessary. Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn 
procedure. See TEST DRIVE RELEARN PROCEDURE .  

2. Disconnect wastegate by-pass regulator valve harness connector. Measure resistance between valve 

terminals. See Fig. 39 or Fig. 40 . If resistance is between 25-35 ohms, go to next step. If resistance is not 
25-35 ohms, replace faulty wastegate by-pass regulator valve. Erase DTC memory. Verify repair. Test is 
complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

3. Connect Scan Tool. Turn ignition on, engine off. Using scan tool, activate wastegate by-pass regulator 

valve. Wastegate by-pass regulator valve should audibly click. If wastegate by-pass regulator valve does 
not click, go to next step. If wastegate by-pass regulator valve clicks. Erase DTC memory. Test is 
complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

4. Disconnect wastegate by-pass regulator valve harness connector. See COMPONENT LOCATIONS e. 

Using adapter cables from Test Kit (VAG 1594), connect Voltage Tester (VAG 1527) to wastegate by-
pass regulator valve harness connector. Observe voltage tester LED. Voltage tester LED should blink 
(light to dark). If voltage tester LED did not blink, go to next step. If voltage tester LED blinks, using 
scan tool, stop actuation of wastegate by-pass regulator valve. Turn ignition off. Replace faulty wastegate 
by-pass regulator valve. Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn 
procedure. See TEST DRIVE RELEARN PROCEDURE .  

5. 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, measure resistance between wastegate by-pass regulator valve harness connector terminal No. 2 
and test box socket No. 104. See . Record resistance reading. Resistance should be a maximum of 1.5 

NOTE:

When using scan tool to activate wastegate by-pass regulator valve, it is barely 
audible, check by touch or use mechanics stethoscope if necessary. 

 

2003 Volkswagen New Beetle GLS 

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

  

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ohms. Check terminal No. 2 of wastegate by-pass regulator valve harness connector for short circuit to 
battery positive and ground. If readings are okay, go to next step. If readings are not okay, repair as 
necessary. Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn procedure. See 
TEST DRIVE RELEARN PROCEDURE .  

6. Using DVOM, check resistance between wastegate by-pass regulator valve harness connector terminal 

No. 1 and fuel pump relay. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in 
SYSTEM WIRING DIAGRAMS. Resistance should be a maximum of 1.5 ohms. If resistance is not 
okay, repair as necessary. Verify repair. Test is complete. If resistance is okay and all wiring is okay, 
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 .  

Fig. 39: Identifying Test Points On Wastegate By-Pass Valve (N75 - Beetle, GTI & Jetta) 
Courtesy of VOLKSWAGEN UNITED STATES, INC.

 

2003 Volkswagen New Beetle GLS 

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

  

Helpmelearn Repair Manuals 

 

Wednesday, December 14, 2005 8:44:38 AM

Page 117 

© 2004 Mitchell Repair Information Company, LLC.