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Ask Chad Farhat Your Own Question
Chad Farhat
Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems
Category: Buick
Satisfied Customers: 3939
Experience:  Owner at Carolina Auto Service & Sales , 20 years Experience in Foreign & Domestic vehicles
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NO COMMUNICATION, 1995 RIVIERA, I OWN A SHOP I,VE TRIED A

Customer Question

NO COMMUNICATION
JA: What is the model/year of your Buick?
Customer: 1995 RIVIERA
JA: Are you fixing your Riviera yourself? What have you tried so far?
Customer: I OWN A SHOP I,VE TRIED A NEW ECM ,RAN A NEW DATA LINE TO OBD CONNECTOR CHECKED POWERS AND GROUNDS
JA: Anything else you want the mechanic to know before I connect you?
Customer: I HAVE UNPLUGGED SDM MODULE AND ABS MODULE
JA: Have you checked the brake fluid? And have the brakes been squeaking?
Customer: I AM TRYING TO GET ECM DATA
Submitted: 3 months ago.
Category: Buick
Expert:  Chad Farhat replied 3 months ago.

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

Expert:  Chad Farhat replied 3 months ago.

Hey how are you

I will try to help you with it

On DLC Terminal #16 do we have B+ on it

Terminal #9 & Terminal #1 needs inspected ,this our data line to ecm

click on link and tell me if you can see the pdf file

and can you run the test A indicated

lets start here

Please let me know

Thank You

Chad Farhat

ASE Certified Technician

Expert:  Chad Farhat replied 3 months ago.

Hints Troubleshooting

1995 Buick Riviera V6-3.8L VIN K

Save Article

1-TRY THE FOLLOWING: 1. Check all DK ORN (835) wiring for an open or short to ground. 2. Check all data line component connectors for proper terminal contact, beginning with suspect component. 3. Check all data line components ground wiring for high resistance (caused by poor terminal contact, frayed wires, etc.). 4. Check all data line components, beginning with suspect component.

2-1995 Buick Riviera V6-3.8L VIN K

TRY THE FOLLOWING: 1. Check all TAN (800) and TAN/WHITE (816) (Oldsmobile Only) wiring for an open or short to ground. 2. Check all data line component connectors for proper terminal contact, beginning with suspect component. 3. Check all data line components ground wiring for high resistance (caused by poor terminal contact, frayed wires, etc.). 4. Check all data line components, beginning with suspect component.

Expert:  Chad Farhat replied 3 months ago.

This is the wiring circuit showing the dlc connection to pcm

can you test these wires

click on link to view

Customer: replied 3 months ago.
the orange wire has 12 volts , tan wire 4 volts with key on i ran a new wire from pin 9 to ecm
Expert:  Chad Farhat replied 3 months ago.

ok after you ran the wire on pin #9 ,still no communication with pcm

is this original pcm, have unplugged it and checked pins on harness side and pcm side ,any bent ,broke ,burned pins inside the connector use a flash light to see better they can be deceiving and hard to see inside connector

Expert:  Chad Farhat replied 3 months ago.

Should be pin # D1 & D2 pcm side cominf from dlc ,tan wire

Customer: replied 3 months ago.
pin 9 from dlc is connected to d1 where is d2 supposed to go
Expert:  Chad Farhat replied 3 months ago.

d2 is not for your vehilce if d1 exist

ok ,so we are sure we have continuty to d2 since new wire

is this orignal pcm ? have you chnaged prior with a know good one

Customer: replied 3 months ago.
i tried a reman ecm from napa
Expert:  Chad Farhat replied 3 months ago.

Between #9 and # 4 do we have infinite continuity

did you disconnect each module at time and try to establish communication each time you disconnected one

TEST A I SENT YOU NEED TO BE RAN EXACTLY STEP BY STEP DID YOU DO THAT

IF It is NOT THE PCM OR WIRING IT IS ANOTHER MODULE CONNECTED TO DLC DOING IT

Expert:  Chad Farhat replied 3 months ago.

Hey how are you

Just checking on you to see if you got the issue resolved or you like additional assistance on it ?

Please let me know

Thank You

Chad Farhat

ASE Certified Technician