Info - Middle East Export HUMMER H2 Tire Service and Cluster Enhancement Special Service Procedures

This bulletin is being revised to add the 2005 model year and update Steps 6, 7, 8, 9 and 10 of the Export H2 Special Cluster Service Replacement Procedure. Please discard Corporate Bulletin Number 04-08-49-008 (Section 08 - Body and Accessories).

Important: This bulletin is intended for use by Middle East dealers only, when servicing vehicles that have been specifically slated for export to this region by General Motors. These vehicles can be immediately identified by the incorporation of the UE9 option code on the Service Parts Identification Label. The procedures found herein are not intended to be used on vehicles that were imported to the Middle East region outside the jurisdiction of the manufacturer (also known as parallel import vehicles).

At the time of export, HUMMER® H2 Middle East vehicles were installed with tires that have not been fully optimized for the Middle East climatic conditions. Until the designated tires are available (expected first quarter of 2006), H2 Middle East export compliant trucks equipped with the UE9 RPO incorporate a unique tire life monitoring system. This following is used to execute the monitoring system:

Cellular and Navigation Antenna and Coaxial Cable

The Cellular and Navigation Antenna on this vehicle is a combination antenna originally intended for domestic only use within the United States of America. In addition to the navigation, or GPS functionality, this antenna incorporates a mobile cellular telephone receiver, including a short, removable mast, which is unused for this tire monitoring system. The navigation portion of this antenna is used to collect the constant signals of the earth orbiting satellites. Within the antenna, is housed a low noise amplifier that allows for a more broad and precise reception of this data. Embedded in the signals provided by these satellites are messages that provide a reference for time, based on Coordinated Universal Time (UTC). This information is constantly being collected and sent to the GPS Communication Module via the GPS coaxial cable, which can be recognized by its blue connector.

To properly collect GPS signals, the antenna must have a clear, unobstructed view of the sky. GPS reception can be restricted when vehicles are parked or pass through areas of dense tree cover, parking structures or tunnels, or are close to tall buildings in major metropolitan regions. In the event the module loses or is removed from battery power, current time and date will be lost and will not be re-established until the module is once again supplied with power and the vehicle placed in an open outside area where GPS signals can be received.

GPS Communication Module

The GPS Communication Module houses a GPS modem that receives and interprets GPS signals. It is powered by a fused, battery positive voltage circuit, attached by means of coax cables to the cellular and navigation antenna, and grounded by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The GPS Communication Module communicates solely with the IPC over the class 2 serial data bus by sending the current time as received by the navigation portion of the cellular and navigation antenna, once per ignition cycle. The GPS Communication Module is capable of setting general fault diagnostic trouble codes (DTCs) in addition to codes that monitor the state of the GPS antenna and coax. These codes are diagnosed under published service information in the Cellular Communication service category.

Instrument Panel Cluster

In addition to all standard functionality, the clusters on UE9 equipped vehicles contain unique software, centered around a "born on date" programmed at the time of manufacture. This "born on date" represents not only the date of manufacture, but also the beginning of the 42-month acceptable lifespan of the tires (as deemed by General Motors) that have been installed at the vehicle plant. The cluster looks for a message sent over the class 2 serial data bus from the GPS Communication Module at every ignition cycle with the latest time and date, as received from GPS satellites. The cluster then compares this received time and date to the "born on date". Once there is a 41-month difference between the "born on date" and the current date as transmitted by the GPS Communication Module, the IPC will send a customer acknowledgeable (displayed once per ignition cycle) "SERVICE TIRES SOON" message across the driver information center (DIC). At this time, the vehicle will need to be returned to the dealership for tire service as described later in this document. Should the customer neglect the "SERVICE TIRES SOON" message and continue to drive the vehicle, the IPC will continue to look for the date transmitted by the GPS Communication Module. Once the IPC sees a 42-month difference between the current and "born on" date, a non-customer acknowledgeable "TIRE SERVICE REQUIRED" message will be sent across the DIC. Not only will this message continue to be displayed until tire service is performed, it will also send a class 2 message to the Powertrain Control Module (PCM) to limit the speed of the vehicle to 40 MPH.

In the event the IPC does not receive an updated time and date, due to an internal failure of the GPS Communication module or the failure or inability of the GPS antenna to acquire a current GPS signal, the IPC will set a U1000 DTC. If the failure continues for 20 consecutive ignition cycles, the IPC will display a "SERVICE VEHICLE SOON " message on the DIC as customer and technician acknowledgement that there is a system malfunction. This message is only used for this tire life monitoring system, and does not refer to any other subsystem on the vehicle.

Action to Take When Tire Service Messages are Displayed

When either the 41 or 42-month timer has expired (displaying either the "SERVICE TIRES SOON" or "TIRE SERVICE REQUIRED" message), the action taken to properly repair the vehicle and return it to the customer is the same. There are however, two repair paths that a technician may take. The determining factor of which is dependant upon the availability of the correct "S" rated tire.

In the event one of the DIC messages is received before "S" rated tires are available, technicians will be directed to first replace all 5 of the "R" rated tires (to include the spare) on the vehicle with another, new set of "R" rated tires. Once this is complete, the technician will need to "reset" the "born on" date in the cluster by means of a Service Programming System (SPS) reprogramming procedure as described later in this document. This action will program the IPC to continue to compare the date received from the GPS Communication Module to the new date programmed into the IPC, to monitor the life of the new tires.

In the event "S" rated tires are available, all 5 of the "R" rated tires should be replaced with the new "S" rated tires, followed by a different SPS special "disable" programming procedure (also described below). This "disable" procedure stops all time and date comparison and commands the cluster to ignore any and all messages sent by the GPS Communication module.

Technicians should contact the General Motors African Middle East Operations Technical Assistance Center (GM AMO TAC) to determine if these tires are available.

Special Diagnostic and Replacement Procedures for the IPC and GPS Communication Interface Module

Middle East Export vehicles using the tire life monitoring system described above require special service procedures when diagnosing any and all issues related to the IPC and GPS Communication Module. For H2 vehicles that incorporate this system, the diagnostics found below should be used, beginning with the "Tire Life Monitoring System-Diagnostic System Check" chart. These diagnostics should be used in conjunction with service information found in SI, where noted. The GPS Communication Module’s United States of America domestic equivalent is the Vehicle Communication Interface Module (VCIM). In any diagnostics within SI where the technician is referred, a callout to the VCIM should be considered the same as a reference to the GPS Communication Module. In addition, the schematic representation of the GPS Communication Module and connector end views will mirror the VCIM and only differ in the fact that the Middle East export vehicles will only utilize the power, ground, GPS coax and Class 2 circuits. All other wiring present is used only on the VCIM.

Tire Life Monitoring System-Diagnostic System Check

Diagnostic Aids

Export H2 Special Cluster Service Replacement Procedure

Diagnostic Aids

SPS "Reset" and "Disable" Programming Event Instructions

Technicians can find step-by-step instructions below for the remote method of SPS programming.

The process for performing an SPS programming event are also found at the Techline® terminal and within SI in the Vehicle Control System subsection under the Programming service category.

1. Turn OFF the ignition.
2. Install the Tech 2® to the DLC.
3. Turn ON the ignition with the engine off.
4. Turn off all vehicle accessories.
5. With the Tech 2®, select F1: Service Programming System.
6. Select F0: Request Info on the Tech 2®.
7. Verify that the displayed VIN matches the vehicle's VIN. If the displayed VIN does not match the actual VIN, write down the actual VIN and correct the VIN at the Techline® terminal.
8. When complete, Exit Service Programming.
9. Turn OFF the Tech 2® and disconnect the Tech 2® from the vehicle.
10. Turn OFF the ignition.
11. Connect the Tech 2® to the Techline® terminal.
12. Select Service Programming System.
13. Select Tech 2® as the tool you are using.
14. Select "Reprogram ECU" as the programming process.
15. Select "Vehicle" as the ECU location.
16. Verify the displayed VIN with the vehicle's VIN. Correct the VIN as necessary.
17. Select PCM as the module to be programmed.
18. Select Vehicle Configuration Index (VCI) as the type of programming to be performed.
19. Contact the GM AMO Technical Assistance Center and inform the consultant that you are performing service on a Hummer H2 Tire Monitoring system. Then, depending upon the procedure being performed, either:

19.1.

Ask the consultant for the Vehicle Configuration Index (VCI) number to "Reset" the "Born on Date" in the IPC, or

19.2.

Ask the consultant for the VCI number to "Disable" the tire monitoring system in the IPC.

20. Enter the appropriate VCI number.
21. Ensure that all connections are secure.
22. Select Next to initiate the download of the new calibration to the Tech 2®.
23. After the download is complete, turn OFF the Tech 2®.
24. Disconnect the Tech 2® from the Techline® terminal.
25. Install the Tech 2® to the data link connector (DLC).
26. Turn ON the Tech 2®.
27. Turn ON the ignition with the engine OFF.
28. Select F1: Service Programming System.
29. Select F1: Program ECU.
30. After the download is complete, Exit Service Programming.
31. Turn OFF the ignition for 30 seconds.
32. Turn OFF the Tech 2®.
33. Turn ON the ignition.
34. Ensure the "SERVICE TIRES SOON" or "TIRE SERVICE REQUIRED" message is no longer displayed on the DIC.