My car just disconnected with scan tools

1997 JEEP GRAND CHEROKEE
200,000 MILES
Avatar
FUCHEN
  • MEMBER
  • 3 POSTS
My jeep drives good. Everthing works good.
But the engine light sometimes on sometime off
I just installed an new computer but still disconnect with scan tools
Does someone can help
Mar 4, 2012 at 7:03 AM
Advertisement
Avatar
KHLOW2008
  • CAR REPAIR CONTRIBUTOR
  • 41,814 POSTS
If you cannot communicate with the ECM, it could be a fault with the power supply to the DLC. Ensure you have battery voltage at pin # 16.
Mar 4, 2012 at 7:50 AM
Avatar
FUCHEN
  • MEMBER
  • 3 POSTS
thank u for helping me?i just checked the DLC the pin#16 is working but still disconnect with scan tools can u please help me again thanks
Mar 6, 2012 at 9:16 AM
Avatar
KHLOW2008
  • CAR REPAIR CONTRIBUTOR
  • 41,814 POSTS
Pin # 4 is ground, ensure it has continuity to body ground.

Check the ground circuits for the engine and computer.
Mar 6, 2012 at 12:53 PM
Avatar
FUCHEN
  • MEMBER
  • 3 POSTS
yesterday i checked the DLC but just pin#16 have power the other 7
have no power
Mar 6, 2012 at 6:30 PM
Avatar
KHLOW2008
  • CAR REPAIR CONTRIBUTOR
  • 41,814 POSTS
Which engine do you have?

What did you use to check the DLC? You must only use a DVOM to test.

Pin # 16 has battery voltage.
Pin # 4 is body ground, you would not gat any power there.
Pin # 3 is CCB (+)
Mar 7, 2012 at 12:20 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.