PCM outputs are all DC to my knowledge. As for the second question, I have some guesses. For one, it could be that it's looking for the brake switch signal to know when to disengage when you hit the brake. It could also be looking for throttle position %.Hey Jeff..
I am bench testing my OSS sensor with a 8 pulse reluctor.
I spin the reluctor with my drill at 1500 RPM.
The sensor generates 0-2.00 volts AC.
Per the wiring diagram. This is feed into the PCM.
The PCM then outputs over the Grey/blk wire to the Speed-o, obd2 port and Cruise control module.
My question to you is :
1. What is the PCM output.. AC, DC??
2. While testing the Cruise control Module by running the Cruise test procedure. KOff, hold cruise OFF, Kon, sequence buttons and watch for actuator movement for system test..
1. The OSS can be completely removed from the system and the Cruise test will run with no error.
Meaning the PCM does NOT perform any Diagnostics of the OSS sensor during the test.
2. IF the Gry/blk wire is cut from the PCM to the Cruise module, the cruise test fails the Pull test and flashes 4 times.
So this means the Cruise test is looking for A signal from the PCM - not based on ANY OSS output..
WHAT is the PCM sending to the Cruise Module to allow the cruise test to complete?
It cant be dc volts??? that would interfere the OSS pass thru signal to the Cruise.
3. I want to figure out how to Bench test the cruise module without the presence of the PCM..
4. IF I can figure out what the PCM is communicating over the gray/blk wire, I could possibly removed the complete Cruise unit, emulate the required speed in put and use the Cruise unit of another project..
Your time and knowledge is GREATLY appreciated.