94 Problems
Thread Starter
3rd Gear
Joined: Jul 2012
Posts: 3
Likes: 0
94 Problems
Hi, I just put in a dewitts rad. and new waterpump my 94 also replaced the pump sensor because I dropped it and the lock tab was broken. Now the electronic temp gauge is stuck at 142 deg. the anlog gauge seems to be working properly, although it still seems to be running hotter than I would have thought with new rad, and a bottle of royal purple coolant additive, stock thermosate it runniong about 210/215 deg. My service engine soon is also on, we did turn the key on so we could move the shifter and move te car while the engine bay electics were unplugged don't know if this is part of the problem. I have tried two different code readers and both say they are unable to communiate with the vehicle. My car is a 94 which is as I understand OBD 1 but it has an OBD 11 connector the manual for the code reader says it could have either but the it wants it set up for the new OBD 11. Help Thanks
Advanced
Joined: Jun 2011
Posts: 81
Likes: 6
From: Baytown, Texas
You can read the codes on your speedometer by jumping the #4 and #12 pins on the OBDII. Both are the 4th pins from the left on the top and bottom rows. Jump the pins and turn the switch on but do not start. It will list all codes and if you miss one, just turn the key off and back on again and it will start over. There are several posts listing the entire procedure with codes. I have saved the instructions as a word file so if you need it. Send me your email and I can send it to you. As far as I know, there are no readers available that read the half OBDI and half OBDII system but you don't need one to read the codes.
Instructor
Joined: Dec 2009
Posts: 189
Likes: 0
From: New Jersey
It could be running hot due to the fans not turning on. The sensor on the pump is the sensor that tells the pcm what the coolant temp is as well as your digital gauge it will cause the fans to turn on/off. On my friends 94 his sensor was getting stuck at 210 degrees on his digital gauge while his analog gauge (which reads off the sensor in the passenger head) was indicating the car was close to overheating and his fans would not turn on. You may have a problem with the new temp sensor you installed in the water pump which may also be causing your check engine light.
As for scanning the car it is an OBD1 pcm like you said but requires an OBDII style connector. I know there are some scanners that can scan this set up but I'm not sure which work. For scanning my 94 I use my laptop and a special cable for 94-95 LT1s and datamaster or freescan.
As for scanning the car it is an OBD1 pcm like you said but requires an OBDII style connector. I know there are some scanners that can scan this set up but I'm not sure which work. For scanning my 94 I use my laptop and a special cable for 94-95 LT1s and datamaster or freescan.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
It sounds like you have an open circuit to the coolant sensor in the water pump. As others pointed out your 94 is OBDI but the connector is identical to newer OBDII cars, the codes cannot be read with an OBDII only scan tool.
See this link to learn how to pull the codes with a paper clip, then for best results troubleshoot the code using the diagnostic tree in the Factory Service Manual.
http://www.digitalcorvettes.com/foru...56&postcount=9
In his case that will likely consist of checking the wiring between the coolant sensor and the PCM, good luck.
See this link to learn how to pull the codes with a paper clip, then for best results troubleshoot the code using the diagnostic tree in the Factory Service Manual.
http://www.digitalcorvettes.com/foru...56&postcount=9
In his case that will likely consist of checking the wiring between the coolant sensor and the PCM, good luck.
