Solved 2000 V8 PCM pin-out / wiring

[Slicer89]

After many issues with my 2000 V8 AWDs output speed sensor, I going to start looking into the wiring. My question is, I found a PCM pin-out diagram for it. I also found the pin for the OSS, I am wondering... Does that go directly to the sensor... Or to another computer or relay, or what? And there is two wires on the sensor connector.... But only one going to the PCM. So is one a ground that goes to the chassis, battery or another computer? If the wire test being bad, I might make a temporary jumper wire to get it working. But unsure since there are two wires coming off sensor, but one going to the pcm.

 

[2000StreetRod]

OSS sensor wiring

According to my 2000 wiring diagrams:

PCM pin 84 (DB/YE wire) > C116 pin 22 > OSS sensor

OSS sensor (GY/RD wire) > C116 pin 4 > S166 > PCM pin 91

"The frequency from this sensor supplies the PCM with output shaft speed information. This information is used in determining shift scheduling, torque converter engagement schedule and EPC pressure."

 

[Slicer89]

According to my 2000 wiring diagrams:

PCM pin 84 (DB/YE wire) > C116 pin 22 > OSS sensor

OSS sensor (GY/RD wire) > C116 pin 4 > S166 > PCM pin 91

"The frequency from this sensor supplies the PCM with output shaft speed information. This information is used in determining shift scheduling, torque converter engagement schedule and EPC pressure."

So there are two wires into the pcm from the oss? Can you post the pin out you have please

 

[2000StreetRod]

PCM pinout

I don't have an electronic copy of the PCM pinout. Here's a link to one: PCM Connector (C202) Early vs Late

Pin 84 is labeled Output Shaft Speed Sensor
Pin 91 is labeled Signal Return

S166 is a splice for most of the sensor (O2, IAT, TPS, ECT, CMP) signal returns.

 

[Slicer89]

I don't have an electronic copy of the PCM pinout. Here's a link to one: PCM Connector (C202) Early vs Late

Pin 84 is labeled Output Shaft Speed Sensor
Pin 91 is labeled Signal Return

S166 is a splice for most of the sensor (O2, IAT, TPS, ECT, CMP) signal returns.

http://www.explorerforum.com/forums/showpost.php?p=2260012&postcount=16

Is the one I was using. It only had one wire for the OSS. But I don't know if it's for my year or not.

So, would it be wise to tap into those two to see if I can get my OSS working again?

Should I check the wiring colour on the sensor and see if it matches those two wires?

Reason I ask, I had a "ford" guy tell me that sometimes the wires get worn out, broke, or damaged and can cause the problem I am facing. He said to try making a "jumper" wire directly from the PCM to the sensor to see if that's the case.


Any input is appreciated, I thought one was signal and other was a ground. But if it's signal "return" for transmission, Shouldn't I tap into it as well for the OSS?

And actual wiring diagram would help...

 

[2000StreetRod]

jumper wire

http://www.explorerforum.com/forums/showpost.php?p=2260012&postcount=16

Is the one I was using. It only had one wire for the OSS. But I don't know if it's for my year or not.

That diagram is correct for your model. As I stated in a previous post Pin 91 is connected to splice 166 which connects to C116 which connects to the other sensor wire. If your TPS is working correctly then the connection between the splice and pin 91 is good. C116 is located between the back of the block and the firewall and is difficult to access.

So, would it be wise to tap into those two to see if I can get my OSS working again?

Should I check the wiring colour on the sensor and see if it matches those two wires?

Reason I ask, I had a "ford" guy tell me that sometimes the wires get worn out, broke, or damaged and can cause the problem I am facing. He said to try making a "jumper" wire directly from the PCM to the sensor to see if that's the case.


Any input is appreciated, I thought one was signal and other was a ground. But if it's signal "return" for transmission, Shouldn't I tap into it as well for the OSS?

And actual wiring diagram would help...

The sensor signal returns are isolated from ground. I advise against grounding them. I suggest that you measure the resistance from the sensor connector pins to the PCM connector pins. That should identify a bad connection if any exists.

 

[Slicer89]

That diagram is correct for your model. As I stated in a previous post Pin 91 is connected to splice 166 which connects to C116 which connects to the other sensor wire. If your TPS is working correctly then the connection between the splice and pin 91 is good. C116 is located between the back of the block and the firewall and is difficult to access.
View attachment 78651



The sensor signal returns are isolated from ground. I advise against grounding them. I suggest that you measure the resistance from the sensor connector pins to the PCM connector pins. That should identify a bad connection if any exists.

As far as I know, My TPS is working. No CEL codes for that, and it idles, revs and shifts fine until the damn OD off light starts flashing, And then it throws a P0720 code... Already replaced the sensor

 

[2000StreetRod]

vehicle speed

On your 2000 model the 4WABS module generates the vehicle speed signal. The rear axle sensor sends a signal to the 4WABS module which outputs a signal to the speed control servo, PCM, radio, instrument cluster, GEM, etc. Does your cruise control work? If not, check the rear axle sensor wiring to it.

 

[Slicer89]

On your 2000 model the 4WABS module generates the vehicle speed signal. The rear axle sensor sends a signal to the 4WABS module which outputs a signal to the speed control servo, PCM, radio, instrument cluster, GEM, etc. Does your cruise control work? If not, check the rear axle sensor wiring to it.

Speedometer and cruise work 100% perfect.

But I decided to trace the wires on the PCM and rewire them directly to the OSS.

AND IT WORKS PERFECTLY. Drove it for about 40 miles.... No CEL, No OD Off flashing. Shifted perfectly.

So I am guessing the factory harness had a bad wire somewhere.

 

[2000StreetRod]

congratulations!

I'm glad you found the problem and a work around. I marked your first post title as solved.

 

[Slicer89]

I'm glad you found the problem and a work around. I marked your first post title as solved.

Thanks! I think anyone with the same on going OSS issue should look into it.