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.
This step tests for valid system power moding in all ignition switch positions.
The presence of DTCs indicate a malfunction within the modules that control the retained accessory power (RAP) feature.
The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
The presence of the following DTCs indicate an internal module malfunction within the modules that control the RAP feature:
• | B1000 |
• | B1652 |
• | B1656 |
• | B1658 |
The presence of DTCs B1982 or B1983 indicate a high or low voltage condition.
A fault with a door switch will prevent the RAP system from functioning properly.
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 each module? | Go to Step 3 | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | |||||||||
Important: Important: The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.
Does the Class 2 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 | |||||||||
Select the display DTCs function on the scan tool for the following modules:
Does the scan tool display any DTCs? | Go to Step 5 | ||||||||||
Does the scan tool display any DTCs which begin with a "U"? | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | Go to Step 6 | |||||||||
Does the scan tool display any of the following DTCs ?
| Go to Diagnostic Trouble Code (DTC) List in Body Control System | Go to Step 7 | |||||||||
Does the scan tool display DTCs B1982 or B1983? | Go to Diagnostic Trouble Code (DTC) List in Engine Electrical | Go to Step 8 | |||||||||
Test the courtesy lamps for proper operation. Refer to Interior Lighting Systems Description and Operation in Lighting Systems. Do the courtesy lamps operate properly? | Go to Diagnostic System Check - Lighting Systems in Lighting Systems |