Service Engine Soon (SES) Light On, DTCs P0087, P0092, P1093, Low Power, No Start, Hard Start, Fuel in Crankcase (Replace All Injectors - New Strategy for High Fuel Return Rates)

This bulletin is being revised to include/update the WPC injector return process and update parts information. Please discard Corporate Bulletin Number 04-06-04-007G (Section 06 -- Engine/Propulsion System).

Some customers may comment on the Service Engine Soon light becoming illuminated. Upon investigation, the technician may find DTCs P0087, P0093 or P1093. Additional customer comments may include a lack of power, a fuel smell on the oil indicator (dipstick), fuel in the engine oil, fuel coming out of the crankcase breather, the engine cranks but does not run, or a hard start condition. This condition will not cause an engine misfire. Do not apply this bulletin to any diagnostic other than what is identified in the chart below.

The fuel injectors have internal conditions that may cause them to return an excessive quantity of fuel to the tank, as well as leak fuel into the crankcase. Due to the excessive return flow and/or leakage, the fuel injection pump may not be able to build up adequate fuel rail pressure.

Important: Before the technician begins diagnostics and repair, be sure to follow the guidelines in Corporate Service Bulletin Number 03-06-04-036A to avoid fuel system contamination.

Important: If the technician commands the fuel rail pressure with Tech 2® to 160 MPa at idle and it reaches at least 158 MPa, then this bulletin does not apply. The technician should then follow normal SI diagnostics. If the rail pressure does not reach 158 MPa, snapshot the data, then follow the diagnostics in this bulletin.

Reference the table below in order to follow current diagnostics for the condition that the vehicle is experiencing. If the diagnostics lead to Fuel System Diagnosis - High Pressure Side, follow the diagnostic until the Fuel Injector Return Flow is measured at each cylinder bank return connection (bank to bank).

Important: If the SES light is illuminated, follow diagnostics for the DTC as indicated with the Tech 2®.

Important:  When installing the new fuel injectors, lubricate the inside of the fuel injector sleeve with clean engine oil prior to installing the injector. Do not lubricate the injector or O-ring seal prior to installation.

Injector sleeves only need to be replaced if there is damage to the tapered sealing surface where it seals against the cylinder head. If an injector sleeve becomes loose or dislodged when replacing injectors, inspect the cylinder head to sleeve mounting surfaces. If there are no witness marks from a combustion leak or coolant leak, reseal the sleeve using SI procedures for Fuel Injector Nozzle Tube Sleeve Replacement.

If fuel return flow on either the right or left cylinder bank is above the initial fuel injector bank return flow value, then replace all eight (8) fuel injectors using the Fuel Injector Replacement procedure in the Engine Controls section of SI.

Record all diagnostic data as outlined on a copy of the attached diagnostic worksheet. The diagnostic worksheet, snap shot of any DTCs, snap shot of the preliminary (actual) fuel rail pressure vs desired as commanded by the Tech 2® and a copy of the repair order with technician comments is to be returned with the removed injectors.

After replacing the injectors, perform the following steps:

1. Install all disconnected and removed components. Refer to the applicable procedures in SI.
2. Start and idle the engine. You may have to prime the fuel system before the engine will start.
3. Connect a scan tool.
4. Command the fuel pressure control to 160 MPa with a scan tool.

•	If the fuel pressure is more than 158 MPa, the system is OK.

•	If the fuel pressure is unable to increase to more than 158 MPa , refer to System Diagnosis -- High Side Pressure in SI.

•	Be sure to record fuel pressure readings on the diagnostic worksheet.

*P/N 97729095 is only available in a merchandising pack quantity of 4. Current order restriction limits availability to 8 per VIN.

If a fuel filter is required, it is the customer's responsibility to replace the filter at their own expense.

Important: This labor operation listed below is covered by emissions and is not subject to the $100.00 deductible. Dealers will need to use the following information when submitting claims on vehicles still covered under that warranty:

2001-2003 Model Year vehicles may be covered by Special Policy Number 04039 A. Please refer to Special Policy Number 04039  A before submitting any warranty claims.

For vehicles repaired under warranty, use:

Important: All replaced injectors must be returned to either the WPC or the core return center (UPS-SCS). Approximately 30% of the warranty claims will be requested back to the WPC.

Important: WAIT UNTIL THE WARRANTY CLAIM IS PAID TO DETERMINE THE LOCATION TO WHICH THE INJECTORS MUST BE RETURNED. IF A WPC PART RETURN REQUEST IS RECEIVED, RETURN THE INJECTORS TO THE WPC. IF A WPC PART RETURN REQUEST IS NOT RECEIVED, THEN RETURN THE INJECTORS TO THE CORE RETURN CENTER. Please follow Corporate Bulletin Number 99-00-89-019E that applies to the WPC return procedures. All injectors of a single engine must arrive at the WPC boxed or bagged together in sets of four or eight injectors. A copy of the part request, repair order with technician comments, snap shot of the preliminary (actual) fuel rail pressure vs desired as commanded by the Tech 2® and the completed diagnostic worksheet should be included with the injectors. The tags found in the replacement injector box must be completed and attached to each injector. The WPC will be verifying sets of injectors for high flow rates.

Effective June 2008, the handling of 6.6L Duramax™ Injector (MY01-MY04 LB7) cores for part number 97729095 will change. The majority of injector cores will now be returned using the normal light core return process to UPS-Supply Chain Solutions (UPS-SCS) . For these cores, credit will be issued using the normal GMSPO core credit process. However, a sampling of injectors replaced under warranty will continue to be returned to the Warranty Parts Center (WPC) for evaluation. This dual process will simplify the core credit process for dealers and provide more efficient handling of the cores overall.

For injector warranty claims, Dealers should continue to hold cores until the warranty claim is paid.

Important: All replaced injectors must be returned to either the WPC or the core return center (UPS-SCS). Approximately 30% of the warranty claims will be requested back to the WPC.

Important: WAIT UNTIL THE WARRANTY CLAIM IS PAID TO DETERMINE THE LOCATION TO WHICH THE INJECTORS MUST BE RETURNED. IF A WPC PART RETURN REQUEST IS RECEIVED, RETURN THE INJECTORS TO THE WPC. IF A WPC PART RETURN REQUEST IS NOT RECEIVED, THEN RETURN THE INJECTORS TO THE CORE RETURN CENTER. Please follow Corporate Bulletin Number 99-00-89-019E that applies to the WPC return procedures. All injectors of a single engine must arrive at the WPC boxed or bagged together in sets of four or eight injectors. A copy of the part request, repair order with technician comments, snap shot of the preliminary (actual) fuel rail pressure vs desired as commanded by the Tech 2® and the completed diagnostic worksheet should be included with the injectors. The tags found in the replacement injector box must be completed and attached to each injector. The WPC will be verifying sets of injectors for high flow rates.

If the WPC does NOT request the injectors, return the cores following the normal light core guidelines (apply thru EPIC/RAPID)* to UPS-Supply Chain Solutions (UPS-SCS)*.

*In Canada, injector cores are now to be returned using the normal core return process using form PC659C (Application for Authorization to Return Material) unless requested by the WPC.

Sets of injectors should be secured with tape or in an overpack container in sets of four or eight for returns to both UPS-SCS and to the WPC . A copy of the repair order and diagnostic worksheet is still requested with the core for both warranty related and regular return.

For returns to UPS-SCS, the core ID label (2) must be visible on the outside end of the package at the opposite end from the part label (1).