Hey guys, my TJ’s throwing P0320. Should I just go ahead and replace the crankshaft position sensor (with a MOPAR) since it seems thats the usual cause of that code, or is there something else I should check first?
Thanks.
Thanks.
P0320 (Crank Sensor?)
- Thread starter James9100
- Start date
Crawlspace
New Member
I checked everything before buying a replacement on Amazon but I had the crank shaft sensor code and a new one did fix the problem on my 4 cylinder.
Crawlspace
New Member
Sounds right but it was 2 years ago. I remember the code description was cam/crank sensor. I tried a few other cam sensors I had laying around and made sure all the wiring was good before swapping the crank sensor on the bell housing witch was the problem.
So I took my TJ for a short drive today to see if I had any symptoms of the crankshaft sensor being bad and it doesn’t seem to. Started fine, no issues while driving (only took it up to 80km, quick backroad drive).
If the sensor is indeed bad would I for sure be getting SOME symptoms? Or should I be looking at something else before replacing the sensor?
Hope someone can point me in the right direction, thanks.
If the sensor is indeed bad would I for sure be getting SOME symptoms? Or should I be looking at something else before replacing the sensor?
Hope someone can point me in the right direction, thanks.
The best direction is to isolate the fault. No one knows your specific problem without troubleshooting first. If they tell you to change the CKPS and it fixes your problem, it's lucky, without troubleshooting first. You need to check for 5v reference, signal wire integrity, ground, and function test with a digital multimeter (assuming you don't have an oscilloscope).
Idk what year your Jeep is so find a wire diagram on this site. Determine your wire color for each.
5V ref: Back probe plug with sensor still plugged in. Should have 5 volts.
Signal: Back probe signal wire with sensor still plugged in. Then, unplug and measure voltage. Should have 5 volts unplugged. This is bias voltage and proves wire integrity back to PCM is good.
Ground: Test for continuity to ground. A few ways to do this. I like to load my grounds to be sure they can actually carry current. Unplug, take a test light from battery positive. Probe ground wire, test light should light.
Function test (with multimeter): Back probe signal wire. Test for voltage DC. There may be voltage present, there might not depending on the position of the flywheel. Slowly rotate crankshaft, either by socket or bumping starter. Rotating by hand works much better for this test. Voltage on the signal wire should cycle between 5 volts and zero (this is your square wave visualized without a scope). If you can get ahold of a scope, then backprobe the signal wire, crank it, and see if you have a 5V square wave.
In other words... This is why people throw parts.
Idk what year your Jeep is so find a wire diagram on this site. Determine your wire color for each.
5V ref: Back probe plug with sensor still plugged in. Should have 5 volts.
Signal: Back probe signal wire with sensor still plugged in. Then, unplug and measure voltage. Should have 5 volts unplugged. This is bias voltage and proves wire integrity back to PCM is good.
Ground: Test for continuity to ground. A few ways to do this. I like to load my grounds to be sure they can actually carry current. Unplug, take a test light from battery positive. Probe ground wire, test light should light.
Function test (with multimeter): Back probe signal wire. Test for voltage DC. There may be voltage present, there might not depending on the position of the flywheel. Slowly rotate crankshaft, either by socket or bumping starter. Rotating by hand works much better for this test. Voltage on the signal wire should cycle between 5 volts and zero (this is your square wave visualized without a scope). If you can get ahold of a scope, then backprobe the signal wire, crank it, and see if you have a 5V square wave.
In other words... This is why people throw parts.
But does the fact that it starts and runs fine rule out my CKP? Typically from what I’ve read you get symptoms like RPM issues, random stalling, or not starting at all. My friends ZJ had the sensor go and it would randomly stall out on him. Can the CKP go bad and not have any issues at all except for the CEL?
Haha ya I’d probably agree but I bought it out of province so I’m working on getting it through inspection, can’t have a CEL.
Then troubleshoot the CEL or take it to a mechanic who will. Have you cleared the code? Does it come back?
So did some testing on the CKP harness with a multimeter…
-5v to 5v supply wire
-5v to signal wire
-I THINK the ground must be good, put a test light on the battery positive terminal and on the harness ground, lit up
-NO resistance between the signal wire and ground wire… this one I’m unsure about, from what I understand from the FSM it should be over 100ohms
-5v to 5v supply wire
-5v to signal wire
-I THINK the ground must be good, put a test light on the battery positive terminal and on the harness ground, lit up
-NO resistance between the signal wire and ground wire… this one I’m unsure about, from what I understand from the FSM it should be over 100ohms
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