Diagnostics Communication
FAULT DIAGNOSIS, DIAGNOSTICS COMMUNICATION
Scan Tool Input And Output Signals
Fault Symptom.
No Scan Tool communication with the Trionic control module.
DIAGNOSTIC PROCEDURE
1. Checking The Scan Tool Connection
Connect the Scan Tool.
The Scan Tool display should light up.
If the display lights up, continue with point 5.
If the display does not light up, continue with point 2.
2. Checking Fuse 23
Check that the fuse is intact.
3. Checking The +30 Supply At The Data Link Connector
Connect the test lamp to pin 9 of the data link connector and a good grounding point.
The test lamp should light up if a +30 supply is present.
If the lamp lights up, continue with point 4.
If the lamp does not light up, check the lead between pin 9 and fuse 23 and take remedial action if necessary.
4. Checking The Data Link Connector's Connection To Ground
Connect the test lamp to pins 9 and 10 of the data link connector.
The test lamp should light up if there is a connection to ground.
If the lamp lights up, check the Scan Tool.
If the lamp does not light up, check the lead between pin 10 and grounding point G24 and take remedial action if necessary.
5. Checking Scan Tool Communication With The Trionic System
Select "TRIONIC".
The Scan Tool should display the Trionic menu.
If communication is established, the fault is of intermittent nature.
If communication is not established, continue with point 6.
6. Checking Scan Tool Communication With Another System
Select another system with which the car is equipped.
The Scan Tool should show the menu for the selected system.
If communication is established, continue with point 7.
If communication is not established, check the Scan Tool.
7. Checking The Wiring
Check The Wiring between pin 1 of the data link connector and pin 33 of the Trionic control module for continuity.
The resistance should be < 1 ohm.
If the resistance is OK, refer to Before Replacing A Control Module.
If the resistance is not OK, check the wiring and take remedial action if necessary.