A quick glance at the settings of your tools will ensure you're getting the most out of your priming process.

The PocketComm tool comes in two basic "flavors", the fuel prime tool and steering column lock tool. Although the tool is sent to you with the correct parameters for the function you requested at the time of the order, there may be more capabilities lurking under that case than you ever thought.

Interfacing With Your PocketComm Tool

The first skill you must learn is how to interface with your pocket-comm tool. The tool is designed to run a serial menu program that allows you to select from and adjust various functions and parameters when connected to a computer through its serial menu port. Setting up this interface requires that you have PocketComm Tool Serial Cable (Part #: IA-401-300-1), a powered OBD-II connection and a PC with an available serial port and a Windows terminal program (like Hyperterminal). There is no special software required to access the serial menu system of the PocketComm, you simply need to start a terminal session with the tool connected to your PC via the serial cable, make sure the serial port COM settings are correct, then plug the tool into a powered OBD-II receptacle.

The tool will automatically run its Bootloader program when it "sees" that it is attached to another device via the serial port, but if you wait about 5 seconds for this Bootloader application to timeout, the serial menu program will takeover. You navigate through the serial menu system by selecting from possible options shown on the terminal window and pressing the corresponding character on your PC keyboard - it couldn't be easier! When prompted to change parameters, you enter the value you desire on your PC and press Enter.

What About Diagnostics?

Through the tools diagnostic functions, you can test the ISO and SCP communication lines, run through a functional check of the LEDs and buzzer, or put the tool into a communication monitoring mode.  The last choice is especially important if you need to determine why another tool is not performing or why a vehicle may not be responding as expected.

Functions and the Function Sequence Table

The standard software with which each PocketComm is configured is capable of performing a host of automotive diagnostic functions: module code clearing on the ISO-9141 line, fuel prime, ARC module setup, steering column lock configuration, fuel fired heater prining, and crash sensor serial number check for Ford's DN series vehicles. The tool can be configured to run one or all of the above functions in any order by configuring the Function Sequence Table.

The Function Sequence Table allows you to choose which function runs first, second, third, etc. It also allows you to configure whether or not the tool should show LED codes for each function. In most cases, the tool is shipped with the correct function for your application already loaded, but if for some reason it needs to changed or updated, the Function Sequence Table defines what the tool does when it is plugged into a vehicle.

Prevent Hydrolocking During Fuel Prime

To make sure that your tool does not hydrolock the vehicles engine during fuel prime, you should verify that the time allowed for the tool to open the injectors isn't excessive. Typically 1-2 seconds is plenty of time to purge the air from fuel lines. If the tool is set for times greater than those, you run the risk of putting too much fuel into the cylinder.

Sometimes, hydrolocking can occur because of a ruptured membrane on certain fuel rail pressure sensors. This ruptured membrane allows fuel to flow back through the vacuum line connected to the pressure senor and into the intake manifold.  If it can be determined what values the sensor emits when its membrane is ruptured, the PocketComm can be configured not to prime when it encounters those values.

Still Dealing with Excessive Crank Times?

Some customers still experience excessive engine crank times after fuel priming. This could be caused for a number of reasons. The first thing that the user needs to do is to watch the LED status on the PocketComm during prime. Notice whether or not the tool is indicating a successful prime, or whether it is failing. Perhaps the tool senses that the fuel system has already been primed and another prime is not necessary.

If the tool is indicating a failed fuel prime, you need to ascertain what is actually happening in the communication link with the vehicle.  This will require you to branch off the OBD-II link and monitor the bus traffic with another tool while you run fuel prime.  After capturing that communication data, it can be reviewed to see what responses the vehicle is giving the tool, what pressures the fuel is getting to, etc. Sometimes, the PCM strategy doesn't support necessary messages to open injectors or turn on the pump - this can be fixed. Other times, the IPS supplier may have changed and the pressure sensor is sending back different values. Either way, the only method of determining what is wrong is to capture the communication dialogue between the PCM and the PocketComm.

If the tool indicates a successful prime and excessive crank times are still occurring, perhaps the fuel target pressure needs to be increased or the total prime time needs to be increased. Another possibility is that the injector bleed time could be increased - but don't make the time long enough to cause hydrolocking!

Sometimes the tool indicates that the vehicle has already been primed. What is happening in this scenario is that the pressure is reaching target values within 4 seconds. To increase the amount of time to prime, you must increase the target pressure.

Code Clearing

Code Clearing only works for those module that communicate on the ISO-9141 line. Code Clearing can be setup to simply clear the DTCs in a module, or it can be configured to clear the DTCs and then wait to see if any mature again. To setup code clearing, you must know the base address of the module and set code clear as one of the functions in the Function Sequence Table.

Specialty Functions

Nearly all of the other functions residing on the PocketComm are specialty functions that only work on specific vehicles. If you have any questions about specialty functions, contact your Dynetics Representative and they can discuss this with you in further detail.

Custom Functions

Dynetics is usually able to turn around custom diagnostic functions for the PocketComm in 2-3 days - depending on the complexity of the function algorithm. To discuss what may be possible with your PocketComm tool, contact your Dynetics IA representative.