CANDI Module Overview (IB04-04-S005)

WARNING: This page is about the Ascender LS, 4.2 S, 4WD, which is a different variant/trim than selected.

Publication date: 2004-08-01
Reference number: IB04-04-S005

CANDI MODULE OVERVIEW

TECHNICAL SERVICE BULLETIN

Reference Number(s): IB04-04-S005, Date of Issue: AUGUST, 2004

ISUZU:	2005 Ascender
AFFECTED VEHICLES:	2005 Isuzu Ascender (US/UT) models.

Service Information

A new Controller Area Network diagnostic interface (CANdi) (see Fig 1 ) has been developed to address new diagnostic communication needs. The CANdi module serves as an enhancement to the Tech 2 and completes the interface necessary to communicate with future on-board computer systems. This system has a single-wire CAN bus for body controls, a medium-speed CAN bus for information and entertainment and a high-speed CAN bus for powertrain controller.

Fig 1: Identifying Controller Area Network Diagnostic Interface (CANdi)

Basic Operation

The CANdi is an in-line cable module that works with existing Tech 2 components including VCI Module, cables and adapters. Installed, the CANdi module is fully compatible beginning with Tech 2 software version 24.004. If a vehicle requires the use of a CANdi module, the Tech 2 will enable features specific to the module.

The primary function of the CANdi module is to add CAN capability to the Tech 2. The following summarizes basic characteristics of the CANdi module:

Supports simultaneous communications on three CAN buses
Provides high-speed UART communications with the Tech 2

The Tech 2 controls CANdi module operation. When installed, the CANdi module does not interfere with any diagnostic procedure currently performed by the Tech 2. Use of the module does not require any physical changes to the Tech 2, cables, or adapters. The module operates transparently until activated by the Tech 2. Upon activation, the CANdi module operates under control of the Tech 2. The Tech 2's application software loaded on Isuzu's GM Based Vehicle PCMCIA card determines all functionality.

NOTE: When functioning properly the CANdi's LED will flash. If a problem occurs, the LED will be constantly illuminated. If the module's light is constantly illuminated contact the ITCS Support Line.

CANdi Module to Tech 2 Connection

The CANdi module connects to the Tech 2 by the existing Data Link Connector (DLC) Cable. The vehicle side connection remains unchanged using the existing adapter to interface between the DLC Cable and the J-1962 DLC adapter (see Fig 2 ).

Fig 2: Connecting CANdi Module To Tech 2 By Existing Data Link Connector Cable

Tech 2/VCI Module/Cable Test

Before using the CANdi module, perform the Tech 2/VCI Module/Cable Test to verify the integrity of the system.

Necessary components:

Tech 2 with VCI module installed
DLC Cable
AC/DC power source
DLC loopback adapter (P/N 3000109), Refer to Fig 3 to view the connectors of the DLC loopback adapter.

Fig 3: Identifying Connectors Of DLC Loopback Adapter

NOTE: To ensure accurate test results, you must use Isuzu's GM Based Vehicle Tech 2 software version 24.004 or later.

Remove the DLC Cable from the Tech 2's VCI Module.
Attach the DLC Cable loopback adapter (Part Number 3000109) to the VCI Module of the Tech 2.
Navigate to the self test option: At the Tech 2 Main Menu, select F3: Tool Options, and then choose Self Test.
Select the test F2: Automated VCI. Screen 1 (shown below) should appear if the test passes.
NOTE: If failures are noticed on the CCD test and the HBCC test, these will not affect diagnostics on Isuzu's GM Based vehicles.
Select F4: Selectable VCI and press the More Test soft key. Choose F1: VCI Dual Uart. Screen 2 appears if the test passes.
Select F5: VCI J1708, and Screen 3 will display.
Select F6: VCI TPU, and Screen 4 will display.
NOTE: When performing the TPU test, it is critical that TPU12 and TPU15 indicate "Pass". If these two TPU channels indicate "Fail", or if they are not present in the above list, then the VCI module for the Tech 2 is possibly damaged. Contact the ITCS Support Line if any problems occur.

Fig 4: Screen 1

Fig 5: Screen 2

Fig 6: Screen 3

Fig 7: Screen 4
Remove the adapter and reattach the DLC Cable.
Attach the DLC loopback adapter at the end of the DLC Cable and repeat steps 3-7.

NOTE: When running the VCI TPU test, TPU12 and TPU15 must show up as pass. If they indicate "fail" or if they are not present on the screen, then the cable might be damaged. This is assuming that TPU12 and TPU15 passed with the DLC loopback adapter connected directly to the VCI Module.
When performing the VCI TPU test, TPU13 and TPU14 will not appear on the screen when running this test with the DLC Cable attached to the Tech 2/VCI Module and the DLC loopback adapter at the end of the DLC Cable.

CANdi Module Updates

Software updates for the CANdi module are stored on Isuzu's GM Based Vehicle 32-megabyte PCMCIA card. The CANdi module will be automatically updated when it is connected to the vehicle's DLC connector and the Tech 2 is powered on. When a CANdi module is updated, the screen (see Fig 8 ) will be displayed. Software update progress will be displayed on the Tech 2 screen.

NOTE: Contact the ITCS Support Line if any problems occur concerning the update, they will be displayed on the Tech 2.

Fig 8: Identifying Tech 2 CANdi Flash

After a successful update, the current CANdi software version can be obtained by selecting:

Select>F9: CANdi Diagnostics - from the Tool Options menu (see Fig 9 ).

Fig 9: Identifying Tool Options Menu - F9: CANdi Diagnostics
Select>F0: POST Results - from the CANdi Diagnostics menu (see Fig 10 )

Fig 10: Identifying CANdi Diagnostics Menu - F0: POST Results

The CANdi POST Results screen (see Fig 11 ) can also be used to determine if the module had any problems during the software update or start-up sequence. The ITCS Support Line may also use the information from the CANdi POST Results screen, if you encounter any problems during an update.

Fig 11: Identifying CANdi POST Results Screen

The latest CANdi software version will be included in TIS software and will be automatically downloaded to the PCMCIA card during a software update. Make sure you have TECH 2 software version 24.004 or later.