Using Jumper Pack During Programming

The length of time it takes to program a module has increased dramatically. Some applications can take as much as 30 minutes. This is due to larger calibration files and GMLAN controllers that take longer to program.

During programming, the ignition key must be turned on, without the engine running, which means the vehicle's systems are operating from the vehicle battery. If system voltage drops below 12 volts, programming is interrupted.

To prevent this from happening, a supplemental external power source would be desirable. However, because clean, stable voltage is critical during module programming, the power source must be carefully selected. Any fluctuation, spiking or loss of voltage can interrupt programming, which could cause the controller to lock up.

A battery charger uses a rectifier to convert AC to DC. In many chargers, the rectifier does not filter out all of the AC, which results in "dirty" DC that is not suitable for programming.

One suitable battery charger that has been validated by GM was introduced in the July 2005 issue of TechLink. The Midtronics 165-PSC charger is available in two amp ratings from GM Dealer Equipment.

The Jumper Pack Solution

Here's another solution to the problem. Many dealerships own a portable 12v jumper pack to supply remote power, for instance to jump-start vehicles in the storage lot. These are also sometimes called battery packs or booster packs.

The 12v jumper pack may be suitable for use during module programming.

There are a few precautions you need to be aware of. First, be sure the jumper pack is fully charged before you use it. The purpose of the jumper pack is to supplement the vehicle's battery, so the pack must be up to the task.

Second, do not have the jumper pack plugged into an AC outlet during the programming event. This may introduce stray AC or other fluctuations into the system, which can interrupt the programming process.

TIP: Vehicles with a high number of modules, such as the 2007 C/K trucks, can draw as much as 10 amps with the ignition on, engine off. Under these conditions, a jumper pack will eventually discharge. So, if you are planning to program multiple modules, it may be advisable to use a battery charger such as the Midtronics 165-PSC.

These jumper packs are available from GM Dealer Equipment (1.800.GM.TOOLS).

Kwikstart Model 6225 (fig. 5)