Scan Tool Inoperative; Scan Tool Does Not Communicate With Uart Data Line - GMC Chevrolet Camaro 1998 Service Manual

Body and Accessories
Wiring Systems 8·379
Scan Tool Inoperative
Circuit Description
Test Description
The data link connector (DLC) provides operating
power for the scan tool at terminal 16 (battery positive
voltage) and at terminal 4 (ground). The DLC
1. The CIG ACCY fuse supplies power to the DLC
terminal 16.
provides the class 2 serial data signal at terminal 2
and signal ground at terminal 5. The DLC provides the
UART serial data signal at terminal 9 and signal
ground at terminal 5. The scan tool will power up with
the ignition off.
4. The DLC battery positive voltage and ground
<
circuits are functioning properly. The malfunction
must be due to the scan tool.
Scan Tool Inoperative
Step Action
Yes No
Test the DLC battery positive voltage circuit for an open or a short to
Go to the applicable
1
ground. Refer to Wiring Repairs.
Diagnostic
Did you find and correct the condition? System Check Go to Step 2
Test the DLC ground circuit terminal 4 for an open. Refer to Wiring
Go to the applicable
2
Repairs.
Diagnostic
Did you find and correct the condition? System Check
Go to Step 3
Inspect for poor connections/terminal tension at the DLC terminals 4
Go to the applicable
3
and 16. Refer to Connector Repairs.
Diagnostic
Did you find and correct the condition? System Check Go to Step 4
The scan tool may be malfunctioning. Refer to the scan tool
Go to the applicable
4
instruction manual.
Diagnostic
-
Did you obtain a properly operating scan tool? System Check
Scan Tool Does Not Communicate with UART Data Line
Step Action Value(s) Yes
No
Use a DMM in order to measure the voltage between B+
1
and DLC terminal 5.
B+ (9-14 V)
Is the voltage within the specified range? Go to Step2
Go to Step 3
2
Inspect for proper connection of the scan tool to the DLC.
-
Is the connection OK between the scan tool and the DLC?
Go to Step 6 Go to Step 7
3 Does the instrument cluster display work?
-
Go to Step 4 . Goto Step 5
Repair a poor connection or open in circuit 451 between
4
the DLC and 8215.
-
-
Has the repair been made? Go to Step 19
Repair a poor connection or open in circuit 451 between
5
8215 and G110.
-
-
Has the repair been made? Go to Step 19
Use the scan tool in order to establish communication with
6
the PCM on a different vehicle.
-
Can communication be established with the scan tool? . Go to Step B Go to Step 9
Repair the poor connectio.n between the DLC and the
7
scan tool. -
-
Is the repair complete? Go to Step 19
1. Reconnect the scan tool to the DLC.
2. Turn the ignition switch to the RUN position.
8
3. Use a scan tool in order to establish communication
-
with the Powertrain Control Module (PCM).
Can the scan tool communicate with the PCM?
Go to Step 10 Go to Step 11