Volkswagen New Beetle. Manual - part 1790

 

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Volkswagen New Beetle. Manual - part 1790

 

 

Fig. 30: Identifying Test Points On 2-Pin Harness Connector 
Courtesy of VOLKSWAGEN UNITED STATES, INC. 

DTC P1248/17656: COLD START INJECTOR (N108) - CONTROL DIFFERENCE 

NOTE:

For connector terminal wire colors, see appropriate WIRING DIAGRAM under 
ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. For component 
locations, see COMPONENT LOCATIONS . 

NOTE:

Before replacing any component, ensure all connectors at component and ECM 
are clean and tight. After making any repairs, disconnect ECM harness 
connector for 10 seconds, connect ECM harness connector and retest system. 
It is necessary to generate an ECM readiness code if ECM memory is cleared, 
battery voltage is disconnected or ECM is disconnected. 

 

2003 Volkswagen New Beetle GLS 

2002-2004 ENGINE PERFORMANCE Self-Diagnostics - 1.9L Turbo Diesel - Beetle, Golf & Jetta (Engine Code ALH)

  

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Possible Effects 

Possible effects are engine runs rough, lack of power, increased emissions and/or poor cold start performance.  

Test Procedures 

1. Ensure there is adequate fuel in tank. Ensure fuel filter is not plugged. Check for air in fuel system. If 

problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, erase DTC 
memory. See CLEARING DIAGNOSTIC TROUBLE CODES (FUNCTION 05) under SELF 
DIAGNOSTIC SYSTEM. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST 
DRIVE RELEARN PROCEDURE 
.  

2.  

Let engine idle. Connect scan tool. See Fig. 1 . Press keys "0" and "1" for address word "Engine 
Electronics", press keys "0" and "4" for "Basic setting" and enter by pressing "Q" key. Press keys "0", "0" 
and "4" for display group "4" and enter by pressing "Q" key. Press keys "0" and "6" for "End output" and 
enter by pressing "Q" key.  

3. Specified value in "display field 3" of scan tool is 7° to 9° BTDC. In approximately 10 seconds "display 

field 3" should change into 3° to 5°. Turn ignition off. If specification is okay, go to step 5 . If 
specification is not obtained, go to next step.  

4. Turn ignition off. To check cold start injector, disconnect 10 pin connector. See COMPONENT 

LOCATIONS . Measure resistance between terminals 9 and 10 (component side). See Fig. 19 . 
Resistance should be 12 to 20 ohms. If resistance is okay, go to next step. If resistance is not okay, 
replace faulty Cold Start Injector (N108). See COMPONENT LOCATIONS . After repairs, erase DTC 
memory. See CLEARING DIAGNOSTIC TROUBLE CODES (FUNCTION 05) under SELF 
DIAGNOSTIC SYSTEM. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST 
DRIVE RELEARN PROCEDURE 
.  

5. Turn ignition off. Disconnect ECM harness connector. Connect VAG 1598/31 test box to ECM harness 

connector. See CONNECTING VAG TEST BOX (leave ECM disconnected).  

6.  

Measure resistance between terminal No. 9 at 10 pin harness connector and socket No. 114 at test box. 
See Fig. 20 . Measure resistance between terminal No. 10 at 10 pin harness connector and socket No. 1 at 
test box. Measure resistance between terminal No. 10 at 10 pin harness connector and socket No. 2 at test 
box. Resistance should be less than 1.5 ohms for each reading. If resistance is as specified, go to next 
step. If any resistance is not as specified, repair open in wiring between 10 pin Cold Start Injector (N108) 
harness connector and ECM. After repairs, erase DTC memory. See CLEARING DIAGNOSTIC 
TROUBLE CODES (FUNCTION 05) 
under SELF DIAGNOSTIC SYSTEM. Verify repair. Test is 

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:

This procedure is used to check Diesel injection timing control range. 

NOTE:

Test box socket numbers correspond to ECM pin numbers. 

 

2003 Volkswagen New Beetle GLS 

2002-2004 ENGINE PERFORMANCE Self-Diagnostics - 1.9L Turbo Diesel - Beetle, Golf & Jetta (Engine Code ALH)

  

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complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

7. Check terminals No. 9 and 10 for short to each other. Check terminals No. 9 and 10 for short to B+. 

Check terminals No. 9 and 10 for short to ground. If wiring is okay, go to next step. If wiring is not okay, 
repair short circuit(s) as necessary. After repairs, erase DTC memory. See CLEARING DIAGNOSTIC 
TROUBLE CODES (FUNCTION 05) 
under SELF DIAGNOSTIC SYSTEM. Verify repair. Test is 
complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

8. Check Needle Lift Sensor (G80). See DTC P1245/17653, P1246/17654 & P1247/17655 . If Needle Lift 

Sensor (G80) is okay, go to next step. If Needle Lift Sensor (G80) is not okay, replace Needle Lift Sensor 
(G80) and No. 3 fuel injector. After repairs, erase DTC memory. See CLEARING DIAGNOSTIC 
TROUBLE CODES (FUNCTION 05) 
under SELF DIAGNOSTIC SYSTEM. Verify repair. Test is 
complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

9. Replace faulty ECM. After repairs, erase DTC memory. See CLEARING DIAGNOSTIC TROUBLE 

CODES (FUNCTION 05) under SELF DIAGNOSTIC SYSTEM. Verify repair. Test is complete. 
Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

DTC P1354/17762: MODULATING PISTON DISPLACEMENT SENSOR (G149) - ELECTRICAL 
MALFUNCTION IN CIRCUIT 

Possible Effects 

Possible effects are poor engine performance, engine stalling, engine will not start, or glow plug indicator lamp 
may flash.  

Test Procedures 

1. Turn ignition off. Connect scan tool, see Fig. 1 . Start engine and let engine idle. Press keys "0" and "1" 

for address word "Engine Electronics", press keys "0" and "8" for "Read measuring value block". Enter 
by pressing "Q" key. Press keys "0", "0" and "1" for display group "1" and enter by pressing "Q" key.  

2. Scan tool display should read "Read measuring value block 1". Coolant temperature readout in "display 

field 4" must be minimum of 185° F (85° C), voltage reading in "display field 3" should be 1.450 to 2.000 
volts. Press "right arrow key", press "0" and "6" for "end output" and enter by pressing "Q" key. If 
voltage reading is not okay, go to next step. If voltage reading is okay, erase DTC memory. See 

NOTE:

Modulating Piston Displacement Sensor (G149) is an integral part of injection 
pump. 

NOTE:

For connector terminal wire colors, see appropriate WIRING DIAGRAM under 
ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. For component 
locations, see COMPONENT LOCATIONS . 

NOTE:

Before replacing any component, ensure all connectors at component and ECM 
are clean and tight. After making any repairs, disconnect ECM harness 
connector for 10 seconds, connect ECM harness connector and retest system. 
It is necessary to generate an ECM readiness code if ECM memory is cleared, 
battery voltage is disconnected or ECM is disconnected. 

 

2003 Volkswagen New Beetle GLS 

2002-2004 ENGINE PERFORMANCE Self-Diagnostics - 1.9L Turbo Diesel - Beetle, Golf & Jetta (Engine Code ALH)

  

Helpmelearn Repair Manuals 

 

Wednesday, December 14, 2005 8:48:23 AM

Page 74 

© 2004 Mitchell Repair Information Company, LLC. 

CLEARING DIAGNOSTIC TROUBLE CODES (FUNCTION 05) under SELF DIAGNOSTIC 
SYSTEM. Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE . If no DTC 
resets, test is complete.  

3. Turn ignition off. Disconnect Modulating Piston Displacement Sensor (G149) 10 pin harness connector, 

see COMPONENT LOCATIONS .  

4. Measure resistance between terminals No. 1 and 2 at Modulating Piston Displacement Sensor (G149). 

See Fig. 19 (component side). Measure resistance between terminals No. 2 and 3 at fuel temperature 
sensor (component side). Resistance should be 4.9-7.5 ohms for each reading. If resistance is as specified, 
go to next step. If resistance is not as specified, replace injection pump. See appropriate ENGINE 
MECHANICAL article in ENGINES. After repairs, erase DTC memory. See CLEARING 
DIAGNOSTIC TROUBLE CODES (FUNCTION 05) 
under SELF DIAGNOSTIC SYSTEM. Verify 
repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE RELEARN 
PROCEDURE 
.  

5. Turn ignition off. Disconnect ECM harness connector. Connect VAG 1598/31 test box to ECM harness 

connector, see CONNECTING VAG TEST BOX (leave ECM disconnected).  

6.  

Measure resistance between terminal No. 1 at 10 pin harness connector and socket No. 108 at test box. 
See Fig. 20 . Measure resistance between terminal No. 2 at 10 pin harness connector and socket No. 106 
at test box. Measure resistance between terminal No. 3 at 10 pin harness connector and socket No. 99 at 
test box. Resistance should be less than 1.5 ohms for each reading. If resistance is as specified, go to next 
step. If any resistance is not as specified, repair open in wiring between 10 pin Modulating Piston 
Displacement Sensor (G149) harness connector and ECM. After repairs, erase DTC memory. See 
CLEARING DIAGNOSTIC TROUBLE CODES (FUNCTION 05) under SELF DIAGNOSTIC 
SYSTEM. Verify repair. Test is complete. Perform ECM relearn procedure. See TEST DRIVE 
RELEARN PROCEDURE 
.  

7. Check 10 pin Modulating Piston Displacement Sensor (G149) harness connector terminals No. 1, No. 2 

and 3 for short to one another. Check terminals No. 1, No. 2 and 3 for short to B+. Check terminals No. 1, 
No. 2 and 3 for short to ground. If wiring is okay, go to next step. If wiring is not okay, repair short 
circuit(s) as necessary. After repairs, erase DTC memory. See CLEARING DIAGNOSTIC TROUBLE 
CODES (FUNCTION 05) 
under SELF DIAGNOSTIC SYSTEM. Verify repair. Test is complete. 
Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

8. Replace faulty ECM. After repairs, erase DTC memory. See CLEARING DIAGNOSTIC TROUBLE 

CODES (FUNCTION 05) under SELF DIAGNOSTIC SYSTEM. Verify repair. Test is complete. 
Perform ECM relearn procedure. See TEST DRIVE RELEARN PROCEDURE .  

DTC P1403/17811: EGR SYSTEM - CONTROL DIFFERENCE 

NOTE:

Test box socket numbers correspond to ECM pin numbers. 

NOTE:

For connector terminal wire colors, see appropriate WIRING DIAGRAM under 
ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. For component 
locations, see COMPONENT LOCATIONS . 

NOTE:

Before replacing any component, ensure all connectors at component and ECM 
are clean and tight. After making any repairs, disconnect ECM harness 

 

2003 Volkswagen New Beetle GLS 

2002-2004 ENGINE PERFORMANCE Self-Diagnostics - 1.9L Turbo Diesel - Beetle, Golf & Jetta (Engine Code ALH)

  

Helpmelearn Repair Manuals 

 

Wednesday, December 14, 2005 8:48:23 AM

Page 75 

© 2004 Mitchell Repair Information Company, LLC. 

 

 

 

 

 

 

 

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