Evening,
I’ve recently bought a 2010 Ford Ranger sport RWD 4.0L V6. Had a few issues wrong with it. I have been trying to diagnose the check engine light and I am now at a stand still. I have replaced the crankshaft sensor, cam shaft sensor and all the spark plugs. After all of that I am given one and only one. P0340 code in yellow on my scanner. (Have been one red for the longest time and now I’m not). The truck does shake and the exhaust does have a muffled sound too it still. Anything would be greatly appreciated. Thanks!

 

Welcome to the forum

Are you looking up codes on a full list?
You need to do that first, never "google" a code, you can do that after, but always look to see what code choices the computer has FIRST

For Cam sensor there are these generic codes
P0340 Camshaft Position Sensor Circuit Malfunction
P0341 Camshaft Position Sensor Circuit Range/Performance
P0342 Camshaft Position Sensor Circuit Low Input
P0343 Camshaft Position Sensor Circuit High Input
P0344 Camshaft Position Sensor Circuit Intermittent

So computer says its NOT high or low, or intermittent, and not out of range

It says there is a circuit malfunction, so that's most likely because there is NO signal at all reaching computer, which is why its the first one, because others are moot if there is no signal, lol

So best bet would be to test the 2 wires from cam sensor back to computer
I don't have a 2010 4.0l diagram
But in a 2008 4.0l the cam sensor has a brown/blue stripe wire and a green/white stripe wire
Brown wire goes to pin 45 on the larger 70 pin computer connector

Green wire goes to pin 58 on same connector BUT..................same green/white wire is shared by several other sensors, same wire color on ECT, TPS, DPFE, MAF, and O2 sensors
So use OHM meter and test green/white wire on Cam sensor to say MAF sensors green/white to see if its 0 OHMs, a good connection, unplug connections for test
It not then you found the problem
If this wire was the problem going to computer ALL those other sensors would set codes

To test the brown wire you will need to pull off the 70 pin computer connector and OHM it out

To test Cam sensor, unplug its wires and set volt meter to AC volts, start engine, test voltage on the 2 connectors on sensor, should see 2 to 4 volts AC at idle
.5 to 1.5v AC when cranking engine if you don't want to start it

If the 2 wires test OK, and the sensor is OK then problem is INSIDE the computer, and the P0340 code was a known issue on Fords when cam circuit failed internally
You can just live with it, or replace the computer


Here is an older Ford full code list: https://www.therangerstation.com/tec...II_codes.shtml