What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

OBD1 Connector wont communicate.

B

BIGCHEVY4X

Registered Member
Joined
Mar 16, 2005
Posts
52
Reaction score
0
Location
El Cajon, CA
I have an 89 blazer TBI and im trying to check the codes and view some data tables. I tried a MAC Scantool with the proper obd1 adapters and power plug and it wouldn't communicate. I also tries a nexus scanner with the same result. So i ordered a cable from http://www.aldlcable.com/ and tried to use the winaldal program on my laptop and still no data. The blazer is in rough shape so i want to verify the aldl port is wired right and have the proper voltage and all that. Where should i start? Thanks
 
Just use a paperclip to jumper the A & B terminals (top right terminals) then turn the key to the ON position and watch the SES light for any codes. Remember that you'll always get a code 12 which is basically a code saying the system is working.
 
If paperclip doesn't work (assuming it is done correctly), there is a wiring issue, the bulb is dead, or the ECM or PROM has a problem. That simple.
 
I read the stickey on checking the codes with the ses light. how to jump it and the code numbers and what they mean however im lost on how to turn the flashes into numbers. Also I need to get the aldl port to work to veiw the data tables becuase its a new engine in a truck thats had a hard life and i have a high idle and a few other small issues and just want to make sure everything is working the best it can. What could cause the paperclip to work but not able to pull info from the port?
 
BIGCHEVY4X said:
I read the stickey on checking the codes with the ses light. how to jump it and the code numbers and what they mean however im lost on how to turn the flashes into numbers. Also I need to get the aldl port to work to veiw the data tables becuase its a new engine in a truck thats had a hard life and i have a high idle and a few other small issues and just want to make sure everything is working the best it can. What could cause the paperclip to work but not able to pull info from the port?
Click to expand...

If the paperclip will make the SES light flash then you're not being able to get data from a scanner or data-logger is an issue with the scanner or data-logger.
 
If your truck is not running AND you are not getting a SES (Service Engine Soon) light start with checking to make sure your ECM is getting both it's 12v UNswitched (Normally Orange) and switched power (Normally Pink or Pink/Black).

The Pin B control wire (the one that you short to ground on Pin A) of the ALDL connector should have +5v on it when the key is on. That wire is normally White/Black.
 
Using Winaldl along with an aldl cable you need to get into configurations and make a couple changes. Baud needs to be set to 4800 on my system i'm using COM port 4 (you need to play with it and see which one works for your system). Make sure you have it set to US and not METRIC. Last, make sure you have the correct ECM number selected (1227747).
 
So I changed the settings and I have data on all the tables now. If I'm reading it correctly I have two codes. A 33 map code and a 42 est code. Before I start messing with it I want to clear it and see if they come back. Can I just pull the ecm fuse or do I have to disconnect the batteries?
 
BIGCHEVY4X said:
So I changed the settings and I have data on all the tables now. If I'm reading it correctly I have two codes. A 33 map code and a 42 est code. Before I start messing with it I want to clear it and see if they come back. Can I just pull the ecm fuse or do I have to disconnect the batteries?
Click to expand...

If you recently disconnected the EST wire in order to time the engine that sets a code 42. Go ahead and clear the codes and see if any codes come back then go from there.
 
When i put the new distributor in i disconnected that wire and set it at 4 degrees. I pulled the ecm fuse and left it out for an hour or so but with the key on before i started the engine both codes were back.

4X4HIGH said:
If you recently disconnected the EST wire in order to time the engine that sets a code 42. Go ahead and clear the codes and see if any codes come back then go from there.
Click to expand...
 
BIGCHEVY4X said:
When i put the new distributor in i disconnected that wire and set it at 4 degrees. I pulled the ecm fuse and left it out for an hour or so but with the key on before i started the engine both codes were back.
Click to expand...

Did you reconnect the EST wire? If you did not that is why the code 42 returned. Also you only need to disconnect the battery or pull the fuse for a minute or less for the codes to clear.
 
4x4high I had a question cuz your truck is the same year. its off topic but by the fuse panel I have two sets of cut wires and im not sure where they go. One is an orange wire side by side to a white wire and the other is a white wire side by side with a black wire. They both appear to go into the harness but im not sure where the other end goes. any idea?
 
BIGCHEVY4X said:
4x4high I had a question cuz your truck is the same year. its off topic but by the fuse panel I have two sets of cut wires and im not sure where they go. One is an orange wire side by side to a white wire and the other is a white wire side by side with a black wire. They both appear to go into the harness but im not sure where the other end goes. any idea?
Click to expand...

Snap a pic and post it and i'll see if I can figure it out.
 
You must log in or register to reply here.

Latest Posts

Top Bottom