CEL Crank position sensor!

[AF808fighter]

Last couple days my truck won't shut off when I turn off the ignition and pull the key out, first few times I had to go backward against the starter, grinding it a little then the truck would turn off. After doing this 3-4 times the check engine light comes on and today at Advance Auto parts they ran the CEL and it came back "crank position sensor". I figured my issue was with the ignition switch which I'll be changing out tomorrow. What does the crank have to do with the whole situation? Is it throwing a code because I cranked against the running alternator/starter to shut the truck off? Truck is not over heating, and there is no popping sound or misfiring..its running smooth as ever. I am now just unplugging the MAF to shut down the engine per one of the members here, thanks for that tip btw.... 130,000 miles and this is the first real problem.

 

[brian2sun]

I would change the ignition and then reset the ECU by pulling the neg. terminal off the battery for about 40-45 minutes. If the problem is still there, then do the CPS.

 

[TheDurk]

I would change the ignition and then reset the ECU by pulling the neg. terminal off the battery for about 40-45 minutes. If the problem is still there, then do the CPS.

I agree--the ECU probably couldn't believe somebody was doing what you were doing and chalked it up to a bad sensor. More technically, the data generated was outside normal parameters as rotations were disturbed by the starter and a CPS code was generated. Reset and keep your fingers crossed.

 

[Runnah]

Hey hate to resurrect and jump this thread all at once but I can’t start a new thread because although I’ve been a member for a while I don’t post much.

So I have a 1996 T4R 3.4L M/T with a 1st gen S/C and URD 7th injector.

It’s been stalling out for last two months. First once in a while and now 2-3 x/mile. Tach goes to zero. No sputtering just dead. If in gear and rolling I just turn the key off and then on and I’m back in business, sailing along. If it occurs while stopped it won’t start until I turn the key to the off position and then back to the on and start. Otherwise it just cranks with no start.

I have a code P0335 Crankshaft position sensor. I tested the sensor as well as ground in pigtail. All good. I’m thinking either the pigtail wire or the ECM is bad. Does anyone have the wiring schematic for the CPS to ECM and whether there would be signal voltage from ECM to sensor or vice versa and what that signal should be. I know the sensor creates its own signal so Idk. Ignition is being lost or shut down and by me having to turn the key off before i can restart says that powering off resets something. I’m thinking a fault in the ECM but I’d like to test first. BTW I replaced the CPS with a good one from my 1st gen Tacoma And as I said bench tested so it’s good. And the original from my 4Runner went into the Tacoma and is working just fine.

Thanks for any help you can give.

 

[TheDurk]

Hey hate to resurrect and jump this thread all at once but I can’t start a new thread because although I’ve been a member for a while I don’t post much.

So I have a 1996 T4R 3.4L M/T with a 1st gen S/C and URD 7th injector.

It’s been stalling out for last two months. First once in a while and now 2-3 x/mile. Tach goes to zero. No sputtering just dead. If in gear and rolling I just turn the key off and then on and I’m back in business, sailing along. If it occurs while stopped it won’t start until I turn the key to the off position and then back to the on and start. Otherwise it just cranks with no start.

I have a code P0335 Crankshaft position sensor. I tested the sensor as well as ground in pigtail. All good. I’m thinking either the pigtail wire or the ECM is bad. Does anyone have the wiring schematic for the CPS to ECM and whether there would be signal voltage from ECM to sensor or vice versa and what that signal should be. I know the sensor creates its own signal so Idk. Ignition is being lost or shut down and by me having to turn the key off before i can restart says that powering off resets something. I’m thinking a fault in the ECM but I’d like to test first. BTW I replaced the CPS with a good one from my 1st gen Tacoma And as I said bench tested so it’s good. And the original from my 4Runner went into the Tacoma and is working just fine.

Thanks for any help you can give.

EWD 1996 below. Props for giving year and engine. Too many people don't.

The only diagnostic in the EWD re the CPS is:

RESISTANCE AT ECU WIRING CONNECTOR
(DISCONNECT WIRING CONNECTOR)
NE -E2 : 140-180 OHMS

Beyond this, the only check on the ECU is swap in a new one.

I don't have a 1996 FSM. You really should follow the protocol in the P0335 section. Closest I have is 2000. Also attached. Probably the same.

Shot in the dark: Have you had the timing belt or Water pump done lately? If so, you should consider the possinility the crank bolt was not tightened to spec and is coming loose. The would allow the crank sprocket to shift forward and signal gets funky. If such work coincided with the onset of problems, they may have damaged one of the teeth on the crank sprocket and that messes up the signal.

 

[Runnah]

Hey thanks for reply and info. Truly appreciated.
RESISTANCE AT ECU WIRING CONNECTOR
(DISCONNECT WIRING CONNECTOR)
NE -E2 : 140-180 OHMS

So I tested continuity along harness between CPS plug and ECU plug(E7 pins 6 and 12) and had continuity. Then tested resistance and came up with 1.7 ohms. Forgive my ignorance but should I be testing resistance between NE and E2? I'm not sure what that is referring to. As I said I have S/C and 7th. E7 pin 12 wiring runs from factory E7 plug into URD module before it then goes into factory ECU. So I tested for continuity along that line as it ran in and out of URD module and came up with no continuity. So I'm not sure if that is normal or not. Do you have insight on that? If not I should hit up the URD thread and ask.

Timing belt was done 50k ago. I pulled and pushed on crank pulley and didn't feel any play FWIW.