There is a TSB. May need a dealer.
Google for #03-06-04-030F: Various Driveability Symptoms Due to Clogged
Fuel Injectors, MIL/SES DTCs P0171, P0172, P0174, P0300,
P1174, P1175 (Clean Fuel Injectors and/or Perform Injector
Test With AFIT - CH-47976) - (Dec 10, 2007)
This bulletin is being revised to update the model year to 2008. Please discard Corporate Bulletin
Number 03-06-04-030E (Section 06 -- Engine/Propulsion System).
Condition
Some customers may comment on any of the following various driveability symptoms:
Cause
Due to various factors, the fuel injectors may become restricted. Extensive testing has demonstrated that fuel
related issues are the cause of clogged injectors. At this point, no specific fuel, fuel constituent, or engine condition
has been identified as causing the restriction. The restriction causes the engine to operate at a lean air fuel ratio.
This may either trigger the MIL to illuminate or the engine to develop various driveability symptoms.
Correction
Fuel injector restrictions, deposits can be cleaned on the vehicle using the following procedure. Under NO
circumstances should this procedure be modified, changed or shortened. As a long term solution, and to prevent
reoccurrence, customers should be encouraged to use Top Tier Detergent Gasoline . For further information on Top
Tier detergent gasoline and fuel retailers, please refer to the following Corporate Bulletin Numbers:
Notice: GM UPPER ENGINE AND FUEL INJECTOR CLEANER is the only injector cleaning agent approved for use with
General Motors fuel system components. Other injector cleaners may cause damage to plastics, plated metals or
bearings. General Motors has completed extensive laboratory testing of GM Upper Engine and Fuel Injector Cleaner,
and can assure its compatibility with General Motors fuel system components, as long as the cleaning procedure is
Subject: Various Driveability Symptoms Due to Clogged Fuel Injectors, MIL/SES
DTCs P0171, P0172, P0174, P0300, P1174, P1175 (Clean Fuel Injectors
and/or Perform Injector Test With AFIT - CH-47976)
Models: 2000-2008 GM Passenger Cars and Light Duty Trucks (Including Saturn)
2003-2008 HUMMER H2
2006-2008 HUMMER H3
2005-2008 Saab 9-7X
with 2.0L, 2.2L, 2.4L, 2.8L, 3.1L, 3.4L, 3.5L, 3.8L, 3.9L, 4.2L, 4.3L, 4.8L, 5.3L, 6.0L, 6.2L
or 8.1L Engine (VINs X, F, D, 4, 5, T, 8, J, E, H, L, 6, K, 1, 2, R, W, S, X, V, T, M, N, U, H, Y,
8, G -- RPOs LNF, L61, LN2, L43, LD9, LK5, LG8, LA1, LX5, LX9, LZ4, LZE, L52, L36, L67,
L26, LZ9, LZ8, LGD, LL8, LU3, LR4, LM7, LH6, LQ9, LQ4, LS2, L76, L92, L18)
and MULTEC® 2 Fuel Injectors
• Extended Crank Time
• Hard to Start
• MIL/SES Illuminated with DTCs
• Hesitation
• Lack of Power
• Surge or Chuggle
• Rough Idle
• Light or Intermittent Misfire
• 04-06-04-047G (U.S. Only)
• 05-06-04-022D (Canada ONLY)
followed correctly.
Injector Cleaning Procedure
The following tools, or their equivalent, are required:
Active Fuel Injector Tester (AFIT- CH-47976)
Some dealers may not have an Active Fuel Injector Tester (AFIT- CH-47976). Dealers can contact 1-800-GMTOOLS
(1-800-468-6657) to order an AFIT- CH-47976. Dealers still can test the fuel injectors without an AFIT.
Refer to Fuel Injector Diagnosis (w/ J 39021 or Tech 2®) in SI.
Important: As mentioned in the AFIT User Guide, vehicles that are not listed in the AFIT menu can still be tested
with the AFIT. Depending on the model, it may be possible to enter the previous model year and proceed with
testing using the DLC connection. If this is not possible on the model that you are working on, it will be necessary
to use the direct connection method outlined in the AFIT User Guide (See Pages 17-31).
General Motors recommends that the Active Fuel Injector Tester (AFIT) be used in testing fuel injectors. If the SI
diagnostics do not isolate a cause for this concern, use the Active Fuel Injector Tester (AFIT - CH-47976) to
perform an "Injector Test" as outlined in the AFIT User Guide.
The AFIT "Injector Test" measures the flow characteristics of all fuel injectors, which is more precise when
compared with the standard Tech 2® fuel injector balance test. As a result, the AFIT is more likely to isolate the
cause of a P1174 DTC (for example: if it is being caused by a fuel injector concern).
The CH-47976 (Active Fuel Injector Tester - AFIT) can also be used to measure fuel pressure and fuel system leak
down. Also, as mentioned in the P1174 SI diagnosis, if the misfire current counters or misfire graph indicate any
misfires, it may be an indicator of the cylinder that is causing the concern. Refer to Fuel Injector Diagnosis (w/CH-
47976) in SI for additional instructions.
Training (U.S.)
