Step
| Action
| Value(s)
| Yes
| No
|
1
| Establish communication with the same system on a different vehicle.
Did you establish communication?
| --
| Go to
Step 2
| Go to
Step 3
|
2
|
- Turn the ignition switch off.
- Inspect for a proper connection of the scan tool to the data link
connector (DLC).
Is the scan tool properly connected?
| --
| Go to
Step 4
| Go to
Step 5
|
3
| Refer to scan tool diagnosis.
Is the scan tool malfunctioning?
| --
| System OK
| --
|
4
|
- Turn the ignition switch on.
- Establish communication with the modules that are connected to
the serial data line.
Did you establish communication?
| --
| Go to
Step 6
| Go to
Step 7
|
5
|
- Repair the connector.
- Reconnect the scan tool.
Did you establish communication?
| --
| System OK
| --
|
6
|
- Turn the ignition switch off.
- Disconnect the module that does not communicate.
- Inspect for a proper connection at the serial data line terminals.
Repair as necessary.
- If OK, measure the resistance from the data link connectors to
the module harness connector.
Does the resistance measure within the specified range?
| 0-5 ohms
| Go to
Step 8
| Go to
Step 9
|
7
|
- Turn the ignition switch off.
- Disconnect the scan tool.
- Connect a test lamp between the data link connector and the battery
power.
Does the test lamp light?
| --
| Go to
Step 10
| Go to
Step 11
|
8
|
- Inspect for power and ground to the module.
- If OK, replace the module.
Is the repair complete?
| --
| System OK
| --
|
9
| Repair the open in the serial data circuit.
Is the repair complete?
| --
| System OK
| --
|
10
|
- Turn the ignition switch off.
- Disconnect all of the modules that are connected to the terminals.
- Measure the resistance on the data link connector from the terminals.
Does the DMM display OL (infinite)?
| --
| Go to
Step 12
| Go to
Step 13
|
11
| Repair the open in CKT 451.
Is the repair complete?
| --
| System OK
| --
|
12
|
- Turn the ignition switch on.
- Measure the voltage on the data link connector from the terminals.
Is any voltage measured?
| --
| Go to
Step 14
| Go to
Step 15
|
13
| Repair the short from the serial data line to ground.
Is the repair complete?
| --
| System OK
| --
|
14
|
- Turn the ignition switch off.
- Repair the short from the serial data line to voltage.
Is the repair complete?
| --
| System OK
| --
|
15
|
- Turn the ignition switch off.
- Reconnect the disconnected module.
- Turn the ignition switch on.
- Establish communication.
Replace the most recently connected module if communication cannot be
established.
- Repeat this procedure until the malfunctioning module is isolated
and repaired.
Did you establish communication?
| --
| System OK
| --
|
