Volkswagen New Beetle. Manual - part 1908

 

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Volkswagen New Beetle. Manual - part 1908

 

 

z

DTC P1546/17954: Wastegate By-Pass Regulator Valve (N75) - Short To B+  

z

DTC P1547/17955: Wastegate By-Pass Regulator Valve (N75) - Short To Ground  

z

DTC P1548/17956: Wastegate By-Pass Regulator Valve (N75) - Open Circuit  

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 - Wastegate By-Pass Regulator Valve 

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. See RETRIEVING DIAGNOSTIC TROUBLE CODES . Turn ignition on, engine 

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

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

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 

NOTE:

When diagnosing DTCs P1546/17954-1557/17965 first check turbocharger 
charge pressure. See TEST PROCEDURE - WASTEGATE BY-PASS 
REGULATOR VALVE , then check TEST PROCEDURE - TURBOCHARGER, 
CHARGE PRESSURE (BEETLE - ENGINE CODE AWV) or TEST PROCEDURE - 
TURBOCHARGER, CHARGE PRESSURE (BEETLE - ENGINE CODE AWP, GTI, 
JETTA & PASSAT) . 

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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and test box socket No. 104. See Fig. 17 . Record resistance reading. Resistance should be a maximum of 
1.5 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. Erase DTC memory. Verify repair. Test is complete. Perform ECM relearn 
procedure. See TEST DRIVE RELEARN PROCEDURE . 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 
.  

Test Procedure - Turbocharger, Charge Pressure (Beetle - Engine Code AWV) 

1. Using a "T" fitting, install Turbocharger Tester (VAG 1397A) in intake manifold to charge pressure by-

pass valve hose. Select measuring range I on turbocharger tester. 

2. With a helper to operate tester from rear seat. Accelerate to wide open throttle from 2000 RPM in 3rd 

gear (M/T) or position "2" (A/T). Press "M" button on turbocharger tester when engine speed is at 3000 
RPM. Boost pressure should be 18.5-20.5 psi (1.3-1.4 bar).  

3. If specified boost pressure is exceeded, go to next step. If specified boost pressure is not as specified, 

recheck wastegate by-pass regulator. See TEST PROCEDURE - WASTEGATE BY-PASS 
REGULATOR VALVE 
and replace as necessary. Repeat turbocharger test.  

4. Check for blockage between charge air cooler and turbocharger. Check wastegate and operating rod 

operation. Ensure wastegate by-pass valve is securely mounted to turbocharger. Repair as necessary. 
Check for stuck wastegate due to corrosion. If valve is stuck, replace turbocharger. Erase DTC memory. 
Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE 
.  

Test Procedure - Turbocharger, Charge Pressure (Beetle - Engine Code AWP, GTI, Jetta & Passat) 

1. Start engine and idle. With a helper to operate tester from rear seat. Using scan tool check duty cycle of 

wastegate by-pass regulator valve. Accelerate to Wide Open Throttle (WOT). Observe duty cycle 
percentage in the 1800-2300 RPM range. Record readings. Duty cycle reading should be from 5 to 95 
percent. If reading is okay, go to next step. If reading is not okay, see CHARGE AIR PRESSURE 
SENSOR 
and replace as necessary. Repeat step 1. 

CAUTION: Test duration during measurement should be limited to a maximum 

of 10 seconds. 

NOTE:

Beetle with engine code (AWP), GTI, Jetta and Passat turbocharger 
performance may only be checked using a scan tool. 

 

2003 Volkswagen New Beetle GLS 

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

  

Helpmelearn Repair Manuals 

 

Wednesday, December 14, 2005 8:44:54 AM

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2. With a helper to operate tester from rear seat. Using scan tool check actual boost pressure at WOT. 

Accelerate to wide open throttle from low speed in 2nd gear (M/T) or 4th gear with Tiptronic System 
(A/T). Press VAG 1551 PRINT button when engine speed is between 1800-2300 RPM. Read boost value. 
Boost value should be 19.6-25.4 psi (1.35-1.75 bar). For engine code AWP boost value should be 24.7-
29.0 psi (1.70-2.00 bar). Compare actual boost pressure with specification in display field 3. Maximum 
difference is 1.5 psi (.1 bar). Repeat measurement if boost pressure was not fully charged or difference 
between actual and specified values was to large.  

3. If boost pressure reading is not okay, see CHARGE AIR PRESSURE SENSOR . If boost pressure is 

still not okay check turbocharger for damage or blockage. Erase DTC memory. Verify repair. Test is 
complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

DTC P1550/17958, DTC P1555/17963, DTC P1556/17964 & DTC P1557/17965 

Code Definition 

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DTC P1550/17958: Charge Pressure - Control Deviation  

z

DTC P1555/17963: Maximum Charge Pressure - Exceeded  

z

DTC P1556/17964: Charge Pressure - Control Limit Not Achieved  

z

DTC P1557/17965: Charge Pressure - Control Limit Exceeded  

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 - Wastegate By-Pass Regulator Valve 

CAUTION: Test duration during measurement should be limited to a maximum 

of 10 seconds. 

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:

When diagnosing DTCs P1546/17954-1557/17965 first check TEST PROCEDURE 
- WASTEGATE BY-PASS REGULATOR VALVE , than check TEST PROCEDURE -
TURBOCHARGER, CHARGE PRESSURE (BEETLE - ENGINE CODE AWV) or 
TEST PROCEDURE - TURBOCHARGER, CHARGE PRESSURE (BEETLE - 
ENGINE CODE AWP, GTI, JETTA & PASSAT) turbocharger charge pressure. 

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

  

Helpmelearn Repair Manuals 

 

Wednesday, December 14, 2005 8:44:54 AM

Page 256 

© 2004 Mitchell Repair Information Company, LLC. 

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. See RETRIEVING DIAGNOSTIC TROUBLE CODES . Turn ignition on, engine 

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

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

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 Fig. 17 . Record resistance reading. Resistance should be a maximum of 
1.5 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 
.  

Test Procedure - Turbocharger, Charge Pressure (Beetle - Engine Code AWV) 

1. Using a "T" fitting, install Turbocharger Tester (VAG 1397A) in intake manifold to charge pressure by-

pass valve hose. Select measuring range I on turbocharger tester. 

2. With a helper to operate tester from rear seat. Accelerate to wide open throttle from 2000 RPM in 3rd 

CAUTION: Test duration during measurement should be limited to a maximum 

of 10 seconds. 

 

2003 Volkswagen New Beetle GLS 

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

  

Helpmelearn Repair Manuals 

 

Wednesday, December 14, 2005 8:44:54 AM

Page 257 

© 2004 Mitchell Repair Information Company, LLC. 

 

 

 

 

 

 

 

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