P1335 Pathfinder CKP (REF) Stumped

[rmcconn2003]

Hi Everyone, I'm working on a 2002 pathfinder R50 US. I replaced the harmonic balancer with an aftermarket (dayco) balancer and upen reassembly I have a P1335 MIL. No MIL before replacement. I have followed the FSM EC-350 through to completion and found the CKP (REF) sensor to have poor Ohms resistance and replaced. The code did not clear and returns within the first few seconds of cranking over (condition A). It starts, but its rough (10-15 seconds). I have confirmed continuity between the terminal 2 reference and terminal 75 on the ECU. I have tested continuity of the entire wire harness separately. I found the alternator to have low voltage and replaced. The alternator is now at 14.1 V. I bench tested the starter and found it to be acceptable. I tested the entire engine harness and found it to be acceptable. I have cleaned all grounds. I have unlearned the ECU. I went through EC-350 again and found the replacement CPK (REF) sensor to be out of Ohms resistance 651 and replaced again. The second replacement also aftermarket did not resolve the issue. The MIL keeps returning. Do I need a Nissan CPK (REF) sensor since the aftermarket bnch test out of spec? Could this be the aftermarket harmonic balancer? I only saw one key way on the crankshaft, could I have installed the harmonic balancer 180 degrees? I have the Nissan data scan OBD2 VAG KKL to connect. Any suggestions would be great as I am stumped

[EdBwoy]

Hello and welcome to the forum.

...Do I need a Nissan CPK (REF) sensor since the aftermarket bnch test out of spec? Could this be the aftermarket harmonic balancer? I only saw one key way on the crankshaft, could I have installed the harmonic balancer 180 degrees? I have the Nissan data scan OBD2 VAG KKL to connect. Any suggestions would be great as I am stumped

I think your problems lie around here:
1. First, I have had good luck with aftermarket (Autozone to be exact) sensors when I was replacing things around my 02 Qx4. However, some people swear by OEM Nissan only when it comes to the position sensors in the other forums.

2. But alas! You said you had no issues before the pulley was replaced (May I ask why you had to replace it btw? It's not what I'd consider a wear item to most Nissans)
I know the FSM troubleshooting guide doesn't point much to the signal generator (the pulley/harmonic balancer), but since you mention that the code comes soon after startup, it rings like especially A or B below:



So I have to ask:

1. Does the pulley wobble by chance?
2. Is it the same offset from the timing cover as OEM when bolted down - accounting for thickness variations, do you think that crank sensor is still seeing the edge of the pulley? Push it 1/8" forward or backward and the sensor might see nothing.
3. Comparing the signal generator notch/tooth between OEM & Dayco, what is the profile of the teeth - just as deep, corners just as sharp, teeth/gap just as wide?
4. Does the replacement have the key - signal tooth angle similar to OEM? Basically, once you have the crankshaft key facing up, do both pulleys installed end up pointing the tooth in the same direction?

[rmcconn2003]

Hi EdBwoy, I appreciate the response! Here's what I collected:

1. Great to know luck with aftermarket sensors. I understand that the AM sensor might not have the same ohms specs.
2. I replaced the balancer because there was a squeal at startup and upon inspection it was looking rough. There was slight cracking and lines in the rubber portion.

The pulley does not seem to be wobbling at all. Alignment with the other pulleys seems good.

Offset appears to be the same. Before installation I put the balancers side by side and checked diameter, clock position of signal generators in comparison to keyway notch, crankshaft diameter was a match, pulleys and grooves were a match.

Distance between the pulley and the sensor is significant (like 1/2"). I expected the sensor to be closer. Attached by two M10 bolts I assume there's no adjustment. I currently have it as close to the pulley as the two bolts would allow, but have also tried centered and furthest away.

The notch profile for the signal generator didn't get a lot of review. They physically appeared identical and I proceeded with installation. I regret to say it's been three weeks since the balancer was replaced and the OE balancer went out with the scrap metal.

For the fun of it after reading your feedback I went out to check for wobble again. Looks good! I turned it off and then turned it on again and now the engine's RPM is revving. It was doing the revving at cold start so the range was about 1100 to 2000 RPM. Warm idle is usually at 750 RPM.

[rmcconn2003]

Please disregard the idle revving. I had to run the idle air volume learn again.

[rmcconn2003]

I believe I've found the error. I spoke to the manufacturer of the replacement part and based on the manufacturer date of my truck (01/2002) they believe the Harmonic balancer (594-345) is the wrong part and that their part is good for Pathfinders manufactured after 07/2002. The signal reference is different and I'll need to find another replacement part as they do not make my Harmonic balancer. I'll report back after correction to verify resolution.

[EdBwoy]

Awesome findings & follow up.
It would be interesting to see what the difference in the pulleys would be.

[rmcconn2003]

I installed a junk yard Harmonic balancer from an 02 manufactured on 04/02 and the code is gone. Looks like my issue is resolved. Auto store will give me a refund too. Thank you for the help!

[EdBwoy]

Out of curiosity, any discernible differences between the junkyard and Dayco one?

[rmcconn2003]

I was also curious about the difference. The only visible change is there is a plastic ring with holes at the end of the pulley that faces the block. The signal generator clock position and the number of timing marks were the same along with the number of belts and grooves. Again, thank you for the help!