P0340 RB25DET ER34 Skyline - Car Wouldn't Start

[GoHashiriya]

Had a strange one today at the track. Engine was hot - very hot, but luckily managed to cool it down for a good 5 minutes before this occured. 

I stalled the car when pulling out of the pit (amateur, I know) and the car wouldn't start. I thought the starter was dead and got some guys to help me push start the car, which was fine. After, I checked the code and it threw a P0340 for the cam sensor - which is where exactly? I replaced the crank sensor (CAS) not long ago, maybe 5k kms, with a rebuilt one here in Japan (could also be a dud). When searching for P0340, I really can't find much related to the 25det. Googling cam sensor just displays images of the crank sensor, I believe the names are used interchangably.

I'm tempted to chuck a new starter in seeing as they're cheap and the car is at 255k on what I believe is the original. But basically, I'll be shipping this car back to Europe from Japan very soon. I have two weeks before my next (last) track session and would really like to not accidentally cook the engine if I stall it when it's hot. There's also the issue that the car has to be operational for the shipping company. So I ask, has anyone had this code/phenomena before and solved the issue?

[joshuaho96]

7 hours ago, GoHashiriya said:

Had a strange one today at the track. Engine was hot - very hot, but luckily managed to cool it down for a good 5 minutes before this occured. 

I stalled the car when pulling out of the pit (amateur, I know) and the car wouldn't start. I thought the starter was dead and got some guys to help me push start the car, which was fine. After, I checked the code and it threw a P0340 for the cam sensor - which is where exactly? I replaced the crank sensor (CAS) not long ago, maybe 5k kms, with a rebuilt one here in Japan (could also be a dud). When searching for P0340, I really can't find much related to the 25det. Googling cam sensor just displays images of the crank sensor, I believe the names are used interchangably.

I'm tempted to chuck a new starter in seeing as they're cheap and the car is at 255k on what I believe is the original. But basically, I'll be shipping this car back to Europe from Japan very soon. I have two weeks before my next (last) track session and would really like to not accidentally cook the engine if I stall it when it's hot. There's also the issue that the car has to be operational for the shipping company. So I ask, has anyone had this code/phenomena before and solved the issue?

What is the actual code? These aren't OBD2 cars, they don't use OBD2 generic codes. If the starter is dead it won't crank. Most likely the code is that your ECU is losing the signal from the CAS altogether for whatever reason. The ECUs in these cars are pretty basic and don't do anything like cam correlation codes or any other plausibility checks.

[GoHashiriya]

That would explain a lot re my findings.  The code I got from NDS was “Code 11 cam angle sensor circuit (CAS) P0340” - should have specified. Also, should have mentioned the engine is stock.
 

The starter motors were cheaper than I thought so ordered one anyway last night, will throw it in this weekend. 

[joshuaho96]

1 hour ago, GoHashiriya said:

That would explain a lot re my findings.  The code I got from NDS was “Code 11 cam angle sensor circuit (CAS) P0340” - should have specified. Also, should have mentioned the engine is stock.
 

The starter motors were cheaper than I thought so ordered one anyway last night, will throw it in this weekend. 

Looks like you want to check for power and ground on the CAS, then try seeing if there's continuity on the cam/home and crank signal wires from the CAS to the ECU harness. You can try also backprobing the ECU connector to see what kind of voltage those wires are delivering in the specified conditions in that table. Easiest way of course is an oscilloscope to read signal from those pins but not sure you can easily find one of those.

You can also just use NDS while cranking to see if it reports RPM. If it does the ECU is getting some kind of signal. Oscilloscope will tell you how noisy it is.

Edited August 23, 2023 by joshuaho96

[GTSBoy]

58 minutes ago, joshuaho96 said:

but not sure you can easily find one of those.

Cheap handhelds available on Aliexpress. I bought one for <<$200 which is excellent (the blue Hantek 2 channel one) which is over $200 now (I think). But there are <<$100 options for even lighter duty examples. If you don't need more than 10MHz it's really very cheap to own one these days.

[GoHashiriya]

7 hours ago, joshuaho96 said:

Looks like you want to check for power and ground on the CAS, then try seeing if there's continuity on the cam/home and crank signal wires from the CAS to the ECU harness. You can try also backprobing the ECU connector to see what kind of voltage those wires are delivering in the specified conditions in that table. Easiest way of course is an oscilloscope to read signal from those pins but not sure you can easily find one of those.

You can also just use NDS while cranking to see if it reports RPM. If it does the ECU is getting some kind of signal. Oscilloscope will tell you how noisy it is.

 

6 hours ago, GTSBoy said:

Cheap handhelds available on Aliexpress. I bought one for <<$200 which is excellent (the blue Hantek 2 channel one) which is over $200 now (I think). But there are <<$100 options for even lighter duty examples. If you don't need more than 10MHz it's really very cheap to own one these days.

Cheers for this. I'll check if we have one at work I can nab and go from there. 

Backprobing is easy, but yeah, need the full story really. If it is $1-200 for an oscilloscope, I might just try the backprobing method and buying a spare CAS to cover me. They're also about $150-200 for these rebuilt units. Plus, I could probably sell it in Europe at a profit if I need to.