DTC CRANK POS SEN(POS)

Post by **Sam Ali** » Thu Oct 28, 2004 5:15 am

Hi,

My mechanics just finished putting back my I30, 97, engine together, and the engine light comes up, upon diagnostic by Nissan tools, the print out showed " P/# 23710-47U14, SELF-DIAG RESULTS, DTC RESULTS, CRANK POS SEN(POS)", My mechanics had been checking the sensor and wiring hardness for 2 days, following instructions on P1336 code and still the same problem. The Sensor was replaced and check OK, so is the wiring hardness (P1336). However, the problem still persist. Any clue what went wrong or what to check ?? Please help !

Thanks,

Sam

Post by **elwesso** » Thu Oct 28, 2004 11:22 am

Possibly the wiring is messed up in other places...

I'll have a maxima guy come look at this thread!

Post by **Sam Ali** » Thu Oct 28, 2004 4:24 pm

Thanks,

The Mechanics did follow FSM per P1336 instrcution for checking wiring hardness. And per FSM, the next to check is the Flywheel for any cracks / Chipped. I really doubt anything would go wrong with the flywheel, since the transmission was untouched, they just finished replacing the timing chain tensioners and guides. I suspect the wiring but they were checked per FSM ........However, I understand P0335 also mean CKP failure, and there are two crank sensors, the one they checked were under the transmission not the one below the timing chain cover. ???? Any difference between P0335 and P1336 codes failure ??

Post by **DAEDALUS** » Thu Oct 28, 2004 7:33 pm

How does the car run? Have they checked the vacuum on it? Why were the chain and other items replaced? How many miles on the car?

Post by **Sam Ali** » Thu Oct 28, 2004 7:44 pm

The Slack side tensioner and Guide were replaced since they were making knocking noise. Now the noise is gone after teh parts replacement. However, the DTC CRANK POS SEN(POS) appear on SELF DIAG, with the engine light on. The engine is running fine, although take a little longer to start - hard start, once the started its is running ok.... My mechanics told me the hard start is cause by the DTC codes. However, it is the third day they are trying to find the fault. They were planning to look at the Flywheel ??? The car is just about 105K miles.
Modified by Sam Ali at 11:09 PM 10/28/2004

Post by **audtatious** » Thu Oct 28, 2004 8:11 pm

That's the flywheel sensor. Page EC-308 of the 97 Nissan Maxima FSM goes through tests they can perform. If there is a wire broken within the wiring harness, they should be able to follow the wiring schematic for that part to determine which one using a multimeter and simply reroute a new wire.

Post by **Sam Ali** » Fri Oct 29, 2004 4:21 am

The mechanics already done that , but I will ask them to check again. They used Multimeter and followed the FSM per P1336 codes. May be they missed something .....

Thanks..

Post by **Sam Ali** » Mon Nov 01, 2004 1:34 am

My Mechanics already check the wiring harness twice, check and replaced flywheel, the only have not been tried out is changing/replacing the ECU. However these DTC error still comes up ??? Any suggestion what to look for ??

Post by **Q45tech** » Mon Nov 01, 2004 3:29 am

Still trying to find a 97 manual, but does this engine have 2 sensors [one for cam and one for crank {?} like more modern nissan engines to show if timing [chain] is off one tooth -----cams from crank. Just a thought.

"engine is running fine, although take a little longer to start - hard start, once the started its is running ok"..............after guide and tensioner replacement?

Post by **Sam Ali** » Mon Nov 01, 2004 3:55 am

As far as I know, it has two crank sensors, one on the crank right below the main bearing (Ref), and one by the flywheel (Pos). and it does have separate cam sensor as well.

Some American Car need to have Crank Possition re-learn procedure, I do not know if this applied to Nissan ....

Post by **Q45tech** » Mon Nov 01, 2004 8:34 am

Check to make sure the chain dots line up with crank at TDC.

OBD2 will throw a code when the crank and cams are in error by even 1 tooth.

Post by **DAEDALUS** » Mon Nov 01, 2004 8:55 am

That's what I was thinking, but I thought it would show up on a vacuum test and with the engine running. The ECU is probably ignoring 1 sensor.

Post by **Sam Ali** » Mon Nov 01, 2004 2:19 pm

Thanks, will check doen and feedback..

Post by **Sam Ali** » Mon Nov 01, 2004 5:40 pm

The nissan mechanics just replaced the ECU and the same DTC codes appeared. So now it boiled down to 2 possibility, Wiring and crank cam tdc allignment. However, I do have one question, will the engine start if the crank/cam chain tdc allignment is off by one tooth ? And how to check without opening the timing chain cover ? Any others symptom to verify ?Thanks,,

Post by **DAEDALUS** » Mon Nov 01, 2004 5:42 pm

It would probably show up in a compression test. One bank would be noticeably different from the other bank...assuming they weren't both off by the same amount. Also a vacuum test might show a shaky needle.

Post by **Q45tech** » Tue Nov 02, 2004 2:42 am

10 degrees isn't much, shows up at idle with engine smoothing out as rpms rise fine above 4,000 rpm..........if valves don't hit.

Sometimes you go back to basics [check timing] especially since timing chain work was done.

Post by **Sam Ali** » Mon Nov 08, 2004 4:43 pm

This is now day 10, the nissan mechanics finally convinced that may be timing chain is off. Upon dismantling, indeed the exhaust sprocket on the front bank cylinder head was off by one tooth. So after couple days the engine was put back and we all think we found the problem. However, upon engine fired up , nothing has changed, the MIL is still on and the DTC code of Crank Pos Sen (POS) still comes up. So here is the summary, all crank sensors replaced/ checked, flywheel, ecu, checked replaced, wiring harness check 3-4 times. The iqnition timing show a 5 degrees advance while normally it should be 10-15% ??? What could have gone wrong ?? The nissan mechanics had contacted all mechanics in my area for clues, and none had experienced this problem. However, I may note that the population of I30 in Indonesia is very small, may be about about 1000 units total the most. What could go wrong ??? The FSM stated that this error is generated when 1. ECU did not received pos signal within few seconds of cranking, 2. ECU did not received POS signal while engine is running. From what we can conclude, it is probably number 1. The FSM also stated: check starter motor.. However, the starter motor started and the engine is cranking... however kind of hard, but does fires up without gas pedal push, but takes may be 5-10 second of cranking.... Any clue ????

The plan to replace the main pulley to see if it help...

Thanks...

Post by **Q45tech** » Tue Nov 09, 2004 3:07 am

Since each cam tooth is 10 degrees and you have a 10 degree error in the electronic vs timing light reading. Still concerned you don't have the timing chain/gears correct.

Consider you can with a variable [offset adjustable] timing light use other cylinders besides number 1 to measure the bank to bank timing as every cylinder is 120 degrees apart

The engine is the same as all Maxima/I30/ even many Pathfinders in Asia.

Post by **Sam Ali** » Tue Nov 09, 2004 1:57 pm

The 5 degree ignition timing is read thru Nissan Consult, will ask them to check suing timing light and see the result..Thanks,

Post by **Sam Ali** » Thu Nov 11, 2004 2:36 pm

We do checked the ignition timing using timing light and electronics and they were both identical, although they seems to stay at 5 degree, but once in a while jumped to 11 degree. However, we decide to go to the basic and using a scope (analog) trying in check the POS,REF and Phase signal from the Crank Shaft and Camshaft. In the process when we are trying to hooked up the probe to the Ref signal, we found out that the REF cabling was spliced up in several location and making contact with the ground cable causing no or intermitten Ref signal. This was uncoovered below the nice hard protective plastic cover underneath the oil pan. Once we fixed the wiring the problem disappeared and the MIL light went away. Apparently, when the ECU is sensing bad REF signal, it flags the POS DTC not the REF DTC,,, only when the POS signal is disconnected it flags out both REF and POS DTC ...

I would thanks all who had help me during this several weeks for all your comments and feedbacks..

The only problem now is that the engine vibrates when put in D or R, and , the tech said it is the motor mounts which had been bad (F and R) that need replacing, idling is fine when in Neutral..