Service Engine Soon (SES) and/or Reduced Power Lamp Illuminated, Limited Throttle Response Following Cold Engine Start Up DTC P0638 (Relocate Small Primary Positive Crankcase Ventilation Hose)

Some customers may comment on the Service Engine Soon (SES) and/or Reduced Power lamp illuminating and limited throttle response immediately following cold engine start up during subfreezing temperatures. Diagnostic trouble code (DTC) P0638 may be stored in the engine control module (ECM).

This condition may be caused by crankcase vapors inside the throttle body collecting at the throttle plate base as engine cools down while shut off, resulting in restricted throttle plate movement immediately following cold engine start up during subfreezing temperatures.

Re-locate primary positive crankcase ventilation (PCV) hose from throttle body to intake manifold top cover and re-route secondary PCV hose over intake manifold. Refer to service procedure in this bulletin. If the vehicle has had PCV hose routing updated per Corporate Bulletin Number 04-06-01-001 (look for labor code J6020 in vehicle history), it is not necessary to repeat steps 29-31.

Caution: Do not allow smoking or the use of open flames in the area where work on the fuel or EVAP system is taking place. Anytime work is being done on the fuel system, disconnect the negative battery cable, except for those tests where battery voltage is required.

Caution: Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

1. Disconnect negative battery cable.

1.1.	Record all of the customer's radio station presets.

1.2.	Turn off all the lamps and accessories.

1.3.	Make sure the ignition switch is in the OFF position.

1.4.	Remove the battery ground (negative) cable and bolt from the battery.




2. Loosen clamp at air cleaner and throttle body assembly.
3. Remove attachment bolts from outlet resonator/duct assembly.
4. Remove outlet resonator/duct assembly.



5. Remove outlet resonator/duct assembly bracket from manifold.



6. Remove intake manifold cover bolts and cover.




Caution: Do NOT use high speed drill motors to drill holes in the magnesium intake manifold cover. Use only slow drill speeds to reduce heat on cover. Dispose of cool magnesium filings immediately after drilling operation. Use appropriate safety precautions when performing drilling operation.

7. Measure and locate new primary positive crankcase ventilation (PCV) grommet position as shown in illustration.
8. Drill a 2 mm to 3 mm (0.079 in to 0.118 in) pilot hole through both the black plastic intake manifold core hole plug (black plastic cover) and the intake manifold cover located 78 mm (3.07 in) from edge at throttle body end and 104 mm (4.09 in) from edge above bank 2 side of the cover.
9. Remove the black plastic cover from the intake manifold cover.

Important: Use metric 11 mm drill bit. This dimension is critical to grommet retention.

10. Enlarge hole on intake manifold cover to 11 mm using a slow drill speed.
11. Remove any burrs from both sides of the drilled hole in the intake manifold cover.



12. Enlarge hole on black plastic cover to 14.3 mm (9/16 in).
13. Remove any burrs from both sides of the drilled hole in the black plastic cover.



14. Install grommet from kit, P/N 15207750, in intake manifold cover. Use water or a drop of engine oil to ease installation of grommet in cover.



15. Clean intake manifold cover before installing to prevent metal filings from entering the engine.
16. Ensure that the five (5) intake manifold cover seals are properly positioned on the intake manifold cover prior to installation of the cover.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

17. Apply Loctite™ 242, or equivalent, to all top cover bolts.
18. Tighten outer intake manifold cover bolts.

Tighten
Tighten outer intake manifold top cover-to-manifold bolts to 4 N·m (35 in-lbs).

19. Tighten inner intake manifold cover bolts

Tighten
Tighten inner intake manifold top cover-to-manifold bolts to 4.4 N·m (39 in-lbs).

20. Install black plastic cover on intake manifold cover. Ensure that the installed grommet on the intake manifold cover fits within the 14.3 mm (9/16 in) hole in the black plastic cover as the cover is installed.



21. Install 90° plastic vacuum fitting from kit, P/N 15207750, into grommet and position as shown.
22. Remove primary PCV hose from throttle body and re-locate to fitting on intake manifold cover.



23. Install vacuum plug from kit, P/N 15207750, on original primary PCV fitting on throttle body assembly.



24. Install outlet resonator duct assembly bracket to intake manifold.

Tighten
Tighten outlet resonator duct assembly bracket-to-intake manifold nuts to 5 N·m (44 in-lbs).




25. Install outlet resonator duct assembly into position.
26. Tighten clamp at throttle body assembly.
27. Position outlet resonator duct assembly to support bracket and install rear bolt only.
28. Tighten clamp at air cleaner assembly.



29. Remove PCV hose from throttle body to PCV oil separator.

Important: Do not remove the braided covering from the hose.

30. Remove rubber isolator from PCV hose.



31. Cut the PCV hose to length as shown. Remove 65 mm (2.5 in) from the throttle body end of the hose.



32. Install PCV hose over intake manifold. Ensure routing is between the A/C line and the intake manifold.
33. Install hose clamp over PCV hose at oil separator.



34. Install hose retainer, P/N 2043150, over PCV hose and secure with remaining front air cleaner outlet resonator.



35. Install secondary PCV hose on throttle body and secure clamp.

Tighten
Tighten two outlet resonator duct assembly-to-support bracket bolts to bolt to 10 N·m (89 in-lbs).

36. Connect negative battery cable.

Important: Clean any existing corrosion from the battery terminal bolt flange and the battery cable end.

36.1.

Install the battery ground (negative) cable and bolt to the battery.

Tighten
Tighten the battery terminal bolt to 16 N·m (12 lb-ft).

36.2.

Program all of the customer's radio station presets and set the radio clock to the current time.

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System for J6020 (Hose, Crankcase Ventilation - Replace). An Add Time has been included for re-routing the PCV hose to the Intake Manifold. This Add Time can only be used once per vehicle.