January 2007 Archives

On the 2006-07 DTS and Lucerne, the evaporator temperature sensor is part of the heater and A/C control lamp wiring harness (fig. 6) and must be serviced as an assembly.

A  Harness

This sensor is used with both manual and automatic control HVAC.

Pinch the evaporator temperature sensor locator tabs together from the inside of the HVAC case for sensor removal.

TIP: You can't pry the sensor out without breaking the case.

- Thanks to Jerry Garfield

When your dealership installs a new or remanufactured OnStar module, the unit removed from the vehicle is the "core," and typically it must be returned to Autocraft Electronics. The core is considered "outstanding" unless it has been received by Autocraft.

OnStar and Autocraft Electronics have been working to reduce the cost and processing requirements for OnStar core returns. The result is a new "Virtual Core" return process. This process allows the dealer parts department to submit credit for a core by logging into the Autocraft Electronics website.

In most cases, after the Virtual Core process is completed, you will be able to dispose of the core instead of having to mail it in for credit. See below for exceptions.

TIP: See below for instructions for setting up an account.

Go to the Autocraft Electronics website at www.autocraft.com.

You can then easily access your dealership's list of outstanding cores, by selecting Account Maintenance and then Outstanding Core.

This opens a list of the cores your dealership has outstanding and not yet returned. Select the Virtual Core button (fig. 7) to the right of a listed core to display the Entry Screen. Here you will enter the necessary information to perform the Virtual Core return, including STID, ESN and Part Number. These numbers are found on the label on the module.

TIP: If you make a mistake with the STID or ESN, you will see a message that tells you to try again. If the information you input does not match the record for the vehicle's VIN, a message will tell you that the virtual core information cannot be verified.

If all the data matches, you will see a message that verifies virtual core information, and an authorization number appears. You can now dispose of the core.

TIP: In some cases, OnStar may want the unit back for assesment or remanufacture. Then, you will be instructed to mail the core instead of disposing of it.

- Thanks to Bob Casper

A 2006 Chevrolet Silverado or GMC Sierra equipped with the 6.6 LLY or LBZ diesel engine may have the SES light on, with DTC P0540.

A loose connection at the Intake Air Heater (IAH) fuse may induce a P0540. Complete the SI diagnostic for any trouble code or symptom found.

During diagnosis for the P0540, inspect for a loose connection at the IAH 175-amp Mega-fuse, located in the Underhood Bussed Electrical Center.

TIP: The left fender upper brace and the secondary UBEC cover need to be removed to inspect the IAH fuse.

Clean and tighten the connection at the 175-amp fuse and evaluate repairs.

- Thanks to Don Langer

The 2006 end year Vehicle Data Recorder (VDR) software J-42598-150 is available in early January 2007 (fig. 8). It adds model year 2007 powertrain coverage for GM vehicles. This software will support both the original VDR J-42598 and the new CAN+ VDR J-42598-B. GMLAN vehicles and live data screen will require VDR CAN+ hardware J-42598-B. This software is compatible with generic PC hardware and will operate on Windows 2000 Professional, and XP Professional.

OBDII Generic Support

An enhancement provided by the new software is the addition of OBDII generic support. This enables the VDR to be used with any OBDII compliant vehicle, not just GM vehicles. You will be able to record snapshots and view the OBDII data stream in the same manner as you can with the current GM data stream.

To use the OBDII option, click on the yellow Select Vehicle button on the left side top tool bar of the VDR Host Software. You must program the VDR in the same manner as you do when selecting a specific GM vehicle. See the user manual for additional instructions.

Software CD and Manual

The user manual for the CAN+ Vehicle Data Recorder J-42598-B is on the VDR Update Software J-42598-150 CD. Adobe Reader is required to view and print the manual. This is included on the VDR Update Software J-42598-150 CD.

To access the manual:

1. Install the VDR Update Software J-42598-150 CD on the PC.

2. If Adobe Reader is installed on the PC, go to step 4. Otherwise, click on START, PROGRAMS, GM VDR HOST APPLICATION, & VDR HOST MANUAL READ ME.

3. Follow the installation instructions on the pop up screen.

4. Click on START, PROGRAMS, GM VDR HOST APPLICATION & VDR HOST MANUAL.

Review of Past Enhancements to the GM VDR.

The live PC data screen allows you to view live data stream information on a standard desktop PC or laptop. To use the Live Data screen, connect the VDR DLC cable to the vehicle and the serial cable (same as Tech 2 serial cable) to a computer running the VDR Host Software.

Select a vehicle, then click on the Live Data button on the top right of tool bar on the VDR Host Software. The same screen that displays the snapshot data will display the live data stream information. DTCs can also be displayed and cleared while viewing the live data stream. See the user manual for additional instructions.

The standard Save As option makes it more convenient for you to save a snapshot to the PC's hard drive or a removable drive such as compact flash or USB flash drive.

TIP: The VDR is useful in solving intermittent driveablility problems, but also has additional uses such as viewing live data (explained above), and capturing information during the crank mode. The CAN+ VDR can be set up to capture data while cranking. This could be helpful in diagnosing a crank/no start or cold/hot start condition.

- Thanks to Mike Banar

This information applies to 1997-2005 GM cars, light duty trucks and utilities equipped with 4L60E, 4L65E or 4L70E (RPO M30, M32 or M70) transmissions.

A replacement pump cover may appear different from the original pump cover. The replacement pump casting may have a boss or a hole and plug to accommodate an input speed sensor (ISS).

Using a light, look inside the stator support and inspect the stator support shaft sleeve. If the sleeve has a large hole and notch, it cannot be used in 1997-2005 transmissions (fig. 9). If the sleeve does not have the large hole and notch in the sleeve it can be used in 1997-2005 transmissions.

A  Notch and hole for ISS equipped pump cover -- CANNOT be used in 1997-2005 transmissions

B  Non ISS equipped -- CAN be used in 1997-2005 transmissions

- Thanks to Chuck Krepp

On a 2007 Buick Terraza, Chevrolet Uplander, Pontiac Montana SV6 or Saturn Relay built before July 24, 2006, the A/C may blow warm or is inoperative.

This is the result of a leak in the low pressure A/C line, which is attached to the compressor closest to the A/C pulley/clutch assembly. The leak is due to the positive battery cable from the starter being routed under the A/C line, applying upward pressure on the A/C line. Over time, this may result in a fractured line or a leak. 
Replace the low pressure line and reroute the positive battery cable over the A/C line
(fig. 10).

- Thanks to Ron Erman

On some 2007 Saturn IONs, it may be difficult to turn the ignition key to the Run position. 
A tab may be improperly placed in the ignition housing (fig. 11). Pivot lever (A) interferes with camshaft (B) at corner. This will require replacement of the housing on cars from VIN 7S825114 to 7S834111. It cannot be repaired. The part number for the replacement housing is 10392736.

- Thanks to Jeff Gorenflo

At first glance, it may appear that the new 2007 Silverado and Sierra fullsize pickups, full-size utilities, Cadillac DTS and Buick Lucerne do not have a Tire Pressure Monitor (TPM) system. All of these vehicles with TPM have a black rubber valve stem instead of the previous metal stem.

To recognize a rubber valve stem with TPM, look for these clues (fig. 12):

- Valve stem cap (A) is longer than usual

- There is a larger than normal amount of exposed brass (B) when the valve stem cap is removed

- The valve stem feels thicker and heavier (C) than most rubber valve stems

The valve stem can be detached from the TPM sensor electronic housing by removing the attaching screw (D).

TIP: Replace the valve stem with a new valve stem at each service event.

The TPM sensor can be retained with the vehicle and attached to the new valve stem. The service part kit to replace the valve stem, including a new screw, is p/n 15263240 for all applications.

Torque the retaining screw to 1.3 N-m (11.5 lb-in).

TIP: The spare tire does not have a TPM sensor.

- Thanks to Jim Will

On a 2007 Saab 9-5 with OnStar Gen 7.0X hardware, the OnStar red LED may be intermittent. A DTC B2476 may be current or in history. The button assembly or VCIM may have been replaced with no change.

The Saab button assembly draws less current than the LEDs used in other GM vehicles. The system is working normally, but may set a B2476 and illuminate the red LED.

Download the Tech 2 update as explained in the box below. (Saab dealers in Canada need to contact OnStar TAC.)

TIP: This is specific Tech 2 software for this DTC. After updating the vehicle with this software, it is necessary to reload the latest version of Tech 2 software (126.000) from TIS. To avoid multiple Tech 2 program changes, it is recommended that all cars in dealer inventory be updated at the same time.

Connect the Tech 2 to the vehicle and make to following selections:

- Diagnosis / 2007 / 9-5 / Body / OnStar / Spare part programming

- For corporate radio select EHU

- For Navigation radio select IHU

- Exit and disconnect Tech 2

Return the vehicle to the customer

No security access is required for this programming.

TIP: All 2007 model 9-5s below VIN 73507800 should be checked for this DTC during PDI.

- Thanks to Jeff Gorenflo