OBD not working

2005 DODGE RAM
309 MILES • 4WD • AUTOMATIC
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BOGOTA
  • MEMBER
  • 1 POST
Radio works, what other fuse do you recommend I check or change?
Apr 21, 2022 at 1:30 PM
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JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

The first thing to do is check fuse 51 (20 amp) in the under-hood power distribution box. If the fuse checks good, confirm there is power to and from it.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Next, if the fuse is good and has power flow, I need you to get a test light or multimeter and check for power at pin 16 on the data link connector (DLC). That pin should have 12v at all times direct from the aforementioned fuse.

If that is good, confirm continuity to ground via pins 4 and 5 at the DLC.

Here is a link you may find helpful when testing wiring:

https://www.2carpros.com/articles/how-to-check-wiring

If you look below, pic 1 shows the DLC pinout. I highlighted pin 16 and placed a + under it indicating power to it. Additionally, I highlighted pins 4 and 5 and placed a -- above them indicating ground.,

Pics 2 and 3 are the computer data line schematic showing the fuse and wiring to pin 16.

Let me know what you find or if you have questions.

Take care,

Joe

See pics below.
Apr 21, 2022 at 6:44 PM
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