Lack of Power or Performance, Hiss Noise on Acceleration, Low Turbo Boost, DTC P0101/P2178 Set (Check Integrity of Charge Air Cooler (CAC) System)

Some customers may comment on one or more of the following conditions:

Diagnosis with a scan tool may reveal DTC P0101 and/or P2178 set in history or current.

This condition may be caused by a leak in the charge air cooler system.

Visually inspect the charge air cooler (CAC) pipes and hoses for any holes or punctures. Check for any damage to the CAC assembly. Verify all hoses are tight and clamps are tighten to 5 N·m(44 lb in). A solution of dish soap and water in a spray bottle can be used to pinpoint any suspected air leaks in the system.

Important: The charge air cooler (CAC) is connected to the turbocharger and to the throttle body by flexible ductwork that requires the use of special high torque fastening clamps. These clamps CANNOT be substituted.

If your dealer has the Duramax Diesel Charge Air Cooler Tester J 46091, it can be used to check the system on this vehicle following the procedure listed below. If your dealer does not have the Duramax Diesel Charge Air Cooler Tester, it can be purchased by contacting SPX Kent-Moore at 1-800-GM-TOOLS.

1. Loosen the charge air cooler hose clamp at the throttle body.
2. Loosen the charge air cooler hose clamp at the charge air cooler outlet pipe.
3. Remove the charge air cooler hose from the throttle body and outlet pipe.
4. Reinstall the charge air cooler hose to the outlet pipe with the elbow facing upward.

Tighten
Tighten the clamp to 5 N·m(44 lb in).




5. Install the J 46091-10 (blue plug) into the open end of the charge air cooler hose and secure with clamp.

Tighten
Tighten the clamp to 5 N·m(44 lb in).

6. Loosen the charge air cooler hose clamp at the turbocharger pipe.
7. Remove the charge air cooler hose from the turbocharger pipe.



8. Install the gauge coupler to the hose and secure with clamp.

Tighten
Tighten the clamp to 5 N·m(44 lb in).

9. Attach the gauge/regulator assembly to the quick connect fitting on the gauge coupler.
10. Connect a air supply to the air valve on the gauge/regulator assembly.
11. Open the air valve sightly, and SLOWLY increase air pressure until the gauge reads 205 kPa (30 psi). If necessary, adjust the air regulator until the gauge reads 205 kPa (30 psi).
12. Close the air valve and monitor the gauge with a stopwatch for 15 seconds. Note any decrease in air pressure.
13. Air pressure should not drop more than 34 kPa (5 psi) in 15 seconds.
14. Remove the air hose, gauge/regulator assembly, coupler and plug.

Caution: DO NOT use any lubricants to aid in the installation of the charge air cooler hoses. Use of lubricants may cause the hoses to blow off when the system is pressurized.

15. Reconnect the charge air cooler hoses and secure with clamps.

Tighten
Tighten the clamps to 5 N·m(44 lb in).

Replace any faulty components that may have been identified from this system check.

For vehicles repaired under warranty, use: