The numbers below refer to the step numbers on the diagnostic table.
Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
The symptom list in Symptoms will determine the correct diagnostic procedure to use.
Step | Action | Yes | No |
---|---|---|---|
1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications |
Does the scan tool communicate with the engine control module? | Go to Step 3 | Go to Data Link References in Data Link Communications | |
Select the ECM display DTC function on the scan tool. Does the scan tool display any cruise control DTCs? | Go to Scan Tool Data List in Cruise Control |
The numbers below refer to the step numbers on the diagnostic table.
Lack of communication may be due to a malfunction in the keyword or the class 2 serial data circuit. The specified procedure will determine the particular condition.
The presence of DTCs which begin with U indicates that some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
Step | Action | Yes | No | ||||
---|---|---|---|---|---|---|---|
1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications | ||||
Does the scan tool communicate with the modules listed above? | Go to Step 3 | Go to Data Link References in Data Link Communications | |||||
3 |
Important:: The engine may start during the following step. Turn the engine OFF as soon as you have observed the crank power mode.
Does the System Power Mode parameter reading match the ignition switch position for all switch positions? | Go to Step 4 | Go to Power Mode Mismatch in Body Control System | ||||
4 | Select the DTCs function on the scan tool for the following modules:
Does the scan tool display any DTCs for the modules listed above? | Go to Step 5 | |||||
Does the scan tool display any DTCs which begin with a "U"? | Go to Diagnostic Trouble Code (DTC) List in Data Link Communications | Go to Step 6 | |||||
6 | Does the scan tool display DTC P0562, P0563, P0616, P0617, P0621, P0622? | Go to Diagnostic Trouble Code (DTC) List in Engine Electrical |