The numbers below refer to the step numbers on the diagnostic table.
This step insures that the battery, and the vehicle primary power and ground systems are functioning correctly.
Lack of communication may be due to a particular malfunction of a serial data circuit. The link to "Scan Tool does not Communicate with Class 2 Device" will provide a list of modules and the associated data network no communication diagnostic link.
This step insures that all data link communication DTCs are diagnosed before system level DTCs.
This step insures that all electronic control unit (ECU) internal DTCs are diagnosed before other system level DTCs.
This step insures that all device voltage DTCs are diagnosed before other system level DTCs.
Step | Action | Yes | No | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Perform the following preliminary inspections:
Did you find and correct the condition? | System OK | Go to Step 2 | |||||||||||||||
2 | Install a scan tool. Does the scan tool power up? | Go to Step 3 | Go to Scan Tool Does Not Power Up in Computer/Integrating Systems | ||||||||||||||
Does the scan tool communicate with all of the expected vehicle control modules? | Go to Step 4 | Go to Scan Tool Does Not Communicate with Class 2 Device in Computer/Integrating Systems | |||||||||||||||
4 | Attempt to start the engine. Does the engine crank? | Go to Step 5 | Go to Symptoms - Engine Electrical in Engine Electrical | ||||||||||||||
5 | Attempt to start the engine. Does the engine start and idle? | Go to Step 6 | Go to Engine Cranks But Does Not Run in Engine Controls - 7.8L | ||||||||||||||
6 |
Important: Do not clear any DTCs unless instructed by a diagnostic procedure. Use the appropriate scan tool selections to obtain DTCs for each of the control modules. Does the scan tool display any DTCs? | Go to Step 7 | Go to Symptoms - Vehicle | ||||||||||||||
Does the scan tool display any DTCs that begin with a "U"? | Go to Step 8 | ||||||||||||||||
Important: If any of these DTCs are displayed, diagnose them before diagnosing any other DTCs or symptoms. Does the scan tool display DTC B1000, B1001, C0550, P0601, P0603, P0604, P0605, P0606, or P1621? | Go to Step 9 | ||||||||||||||||
Important: If any of these DTCs are displayed, diagnose them before diagnosing any other DTCs or symptoms. Does the scan tool display DTC B1372, C0899, C0900, P0562, or P0563? | Go to Step 10 | ||||||||||||||||
10 |
Important: If any of the remaining DTCs are powertrain DTCs, select Capture Info in order to store the powertrain DTC information with a scan tool. If multiple DTCs are stored, diagnose the DTCs in the following order
Diagnose the remaining DTCs. | -- |