Pinpoint Test I: No Power To The Scan Tool

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Module Communications Network for schematic and connector information.

Normal Operation 

The scan tool is connected to the data link connector (DLC) to communicate with the high speed controller area network (HS-CAN) and International Standards Organization (ISO) 9141 communications networks.

This pinpoint test is intended to diagnose the following:

• Fuse
• Wiring, terminals or connectors
• DLC
• Scan tool

PINPOINT TEST I: NO POWER TO THE SCAN TOOL 

1. I1 CHECK THE DLC PINS FOR DAMAGE 
   NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test.
   • Disconnect the scan tool cable from the DLC.
   Fig 1: Checking DLC Pins For Damage
   Courtesy of FORD MOTOR CO.
   • Inspect DLC pins 4, 5 and 16 for damage.
   • Are DLC pins 4, 5 and 16 OK? 
   1. YES  : Go to  I2.
   2. NO  : REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
2. I2 CHECK THE DLC VOLTAGE SUPPLY CIRCUITS FOR AN OPEN 
   • Measure the voltage between the DLC C251-16, circuit SBP29 (GY/RD), harness side and ground.
   • Is the voltage greater than 10 volts? 
   1. YES  : Go to  I3.
   2. NO  : VERIFY the SJB fuse 29 (20A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.
3. I3 CHECK THE DLC GROUND CIRCUITS 
   • Measure the resistance between the DLC C251-4, circuit GD161 (BK/YE), harness side and ground; and between the DLC C251-5, circuit GD174 (BK/WH), harness side and ground.
   • Are the resistances less than 5 ohms? 
   1. YES  : REPAIR the scan tool. REPEAT the network test with the scan tool.
   2. NO  : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.