Scan Tool Does Not Communicate with Class 2 Device

SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE

CIRCUIT DESCRIPTION
The powertrain control module (PCM) is connected to the class 2 serial data circuit. The class 2 serial data circuit is used for diagnostic purposes only in this vehicle. Connecting a scan tool to the data link connector (DLC) allows communication with the PCM for diagnostic purposes. DTCs may be set due to this symptom and during this diagnostic procedure. Complete the diagnostic procedure in order to ensure all the DTCs are diagnosed and cleared from memory.

DIAGNOSTIC AIDS
The PCM is the only module on the class 2 serial data buss on this vehicle. The most likely cause of the buss failure will be a short or open.

TEST DESCRIPTION

Step 1 - Step 8:

Step 9 - Step 13:

The numbers below refer to the step numbers on the diagnostic table.
2. A partial loss or intermittent loss of communication in the class 2 serial data circuit uses a different procedure than a total loss of communication of the class 2 serial data circuit.
10. If there are no current DTCs that begin with the letter "U", the communication concern has been repaired.
11. The communication concern may have prevented diagnosis of the customer complaint.