Trans Range Sensor
^^^^^^^^^
is that the output speed sensor?

 

No,, Trans Range is the gear selector position switch/sensor. Mounts external/within the trans shift shaft-lever..

 

Ok, so that's what it keeps coming back to is the Trans Range Sensor....

What's really pissing me off is there is NO code being thrown. My check engine light isn't even on... UGH I searched, I have the code reader and the digital mutlimeter but I have NO idea what a flex probe kit is or even how to use one.... :/

 

If you follow the ohms tests at the connectors/component in the testing procedures , it should prove out if the range sensor is good/bad, possible circuit drop out, or connector issues etc. Don't worry about the probe kit.

LFC 4 is a diagnostic trouble code. Standard code readers are very limited to what type of codes they can read, most only 'P' codes=powertrain.

 

Hayapower-

I did the Ohms test on the wire harness/connector and with the multimeter set on Ohmns settings and 20K it read 7.84 Ohmns. The stuff you sent me said it's more than 5 Ohmns to change out the speed control actuator... So?????????

 

No, the test are asking if the reading you get or are seeing is 'less' than 5 ohms. So,, NO would be the answer and move on to the next step..

Basically what the tests are doing is checking the harness between the actuator to the trans range sensor (Both test done in Neutral) and the sensor itself.

Test 'I' Ignition OFF while disconnecting the C122 connector, then turn ignition ON,, select Neutral gear range (trans range sensor still connected) then measure resistance between the C122 on the connector view supplied (harness side for testing , not the actuator itself) Green/White wire-circuit CET21 to a good ground point.
Question is,,is the resistance 'less' than 5 ohms.. If you did the test exact as guided, and had 'less' than 5 ohms the actuator would have been suspect.

So if you got 7.8ish the answer would have been NO taking you to test 'I'2

There, the test says- Parking Brake ON
Ignition OFF
Disconnect the trans range sensor ( Connector C167) see connector view.
Again,, select Neutral
Now,, you'll measure resistance on the trans 'range sensor' itself (not the harness connector end) from Pin 1 to Pin 8 on the sensor.
Again, the question is, are you seeing 'Less' than 5 ohms resistance (?) Yes/No?

Test/Check 'I'3 is to make sure the sensor is in alignment ( doubt it moved, but connector issues, corrosion, pins issues etc may be cause)

Test/Check 'I'4
Gear select- Park
Measure C167 connector Black/Grenn wire (circuit GD120) to ground. Again, the question is are you seeing less than 5 ohms.. Then, depending on Yes/No what action to take to for circuit/wire to repair or diagnose..

All the Checks/Tests within the Flash code 4 are leading you towards the harness between the actuator and the trans range sensor, more likely the trans sensor itself, or a possible alignment issue. But don't rule out connector issues/corrosion, harness opens/shorts as cause before replacing any parts.

 

Well I'm going today to buy a better voltmeter bc this little janky piece of crap I have half the time doesn't even work.. So, I'm going to buy a new one and retest the speed control actuator and see what it says with new multimeter and then I'll go from there......

 

Remember, your testing the "harness" from the speed actuator connector down to the trans range sensor, then test/check, the trans range sensor itself per LFC #4 DTC's guidelines, not the actuator....

 

Ok, I got a new multimeter, a nice one this time. I retested the actuator wire harness, I unplugged it, set the e-brake, turned the key to "on" and selected "n" and tested it, it reads 11.5 to 11.8 Ohms. I'm waiting for the motor to cool down to pull the Trans Range/Neutral Safety Switch wire harness off to test it and the sensor itself. I'll come back and report those readings as well.

 

Ok, motor cooled off, the wire harness to the TR read- 1.? (with ignition off) with it on it read .96 at this step which is i4 bc i3 the TR seems to be positioned correctly, it says repair circuit CET21 (GN/WH) , Repeat the self test. If no it says Repair circuit GD120 (BK/GN), Repeat self test.
It has the i5 test but no where on i4 does it say yes or no to go to i5... Which i4 is the Brake Position Switch (cruise control) and it's brand new...

As for going any further to i6, which is the resistance between the speed actuator harness and the cruise control switch (brake position switch) I don't have long enough cables for my meter to test them against each other. Same as i7 the pcm against the brake position switch (cruise control switch....

So what it's saying is the Trans Position Sensor/Neutral Safety Switch wire harness is bad and needs to be replaced??