| Subject: | PCM Reprogramming and Data Line Diagnosis Using J 42236-A |
| Models: | 1997-2004 Chevrolet Corvette |
This bulletin is being revised to add the 2004 model year. Please discard Corporate
Bulletin Number 02-06-04-022 (Section 06 - Engine/Propulsion System).
All 1997-2004 Chevrolet Corvette models are equipped with two Class II
data line splice packs (also called star connectors). Essential tool J 42236-A
is designed to connect to these splice packs and is required for PCM reprogramming
and data line diagnosis.
The J 42236-A allows the technician to isolate one module at a time
from all others on the Class II data line. When a module is isolated, the Tech 2
can be used to read data, send commands and reprogram that module (if applicable).
When reprogramming the PCM, the on-board control modules may attempt to communicate
with the PCM across the Class II data link. When this happens, the reprogramming
procedure is interrupted and will result in a non-functional PCM and require replacement
of the PCM. When reprogramming the PCM, the service method listed in Service Information
(SI) must be used to ensure that no other modules in the vehicle attempt to communicate
with the PCM during the reprogramming procedure.
Important: Before installing the J 42236-A for
diagnosis or reprogramming, check and record all stored DTCs.
| • | J 42236-A installs to the splice pack/star connectors. These splice
packs are located to the left of the body control module (BCM). The splice packs/star
connectors are stand alone and do not plug into the BCM. |
| | The BCM is located
behind the passenger floor access panel. |
| • | Both splice pack/star connector shorting bars need to be removed from
the splice pack/star connector. This can be done by squeezing both ends of the shorting
bar and pulling it away from the splice pack. |
| • | The splice packs/star connectors may have to be removed from their mounting
pins in order to install the J 42236-A. The splice packs/star connectors must
be visually inspected to ensure the proper cable from the J 42236-A is installed
on the correct splice pack/star connector. |
| • | Cable #1 connects to the star connector with eight, nine or ten wires.
Cable #2 connects to the star connector with four incoming wires. |
| • | Refer to the Information Card included with the tool
(and shown in the illustration) for the correct J 42236-A settings in order
to access the desired Class II module. |
After Data Line Diagnosis or PCM Reprogramming
- Disconnect the J 42236-A and reinstall both shorting bars on to
the splice packs. Both splice pack/star connector shorting bars are identical and
must be installed for proper vehicle operation.
- Check and clear all vehicle modules for trouble codes. Refer to SI in
order to correct any trouble codes that may have been recorded prior to diagnosis
or reprogramming and are still present.
- Any trouble codes that may appear after diagnosis or reprogramming must
also be diagnosed using SI.
