PI0940

SB-10052029-5655
File in Section:
Service Bulletin
Bulletin No.:
Date:
PI0940
April, 2013
PRELIMINARY INFORMATION
Subject:
Malfunction Indicator Lamp (MIL) On, DTC P0171 Set
Models:
2013 Cadillac ATS
Equipped with 2.0L or 2.5L Engine (RPOs LTG, LCV)
Attention: This PI only applies to vehicles with the 4 cylinder engine with vacuum controlled
engine mounts.
Condition/Concern
Some customers may comment that the malfunction indicator lamp (MIL) light is on. Technicians may find DTC
P0171 set.
Check possible causes per normal SI diagnostics and correct other conditions as applicable.
Recommendation/Instructions
Check the engine mount vacuum control system for leaks with vacuum only. Do not use positive pressure to check
the engine mount vacuum control system for leaks at the tank. Refer to Engine Mount Vacuum System Leak Test in
Vacuum Operated Engine Mounts Description and Operation in SI.
2846245
Legend
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
Check Valve
RH Engine Mount Bracket
LH Engine Mount Bracket
LH Engine Mount
Vacuum Tank Assembly
Idle Valve Assembly
Bounce Valve Assembly
Filter Assembly
Engine Mount Vacuum Hose Assembly
RH Engine Mount
If a leak is found at the vacuum tank, remove and replace the tank and recheck for leaks using vacuum only. Refer to
SI for Engine Mount Vacuum Tank Replacement.
If a leak is found in another component, refer to SI for replacement procedure.
If a fluid is found in the vacuum lines or tank, the entire vacuum system needs to be replaced because of
contamination. If fluid is found in the vacuum system, check for source of fluid.
Note: The engine mounts are filled with fluid.
Warranty Information
For warranty use the appropriate labor operation the repair performed.