No power to cam or crank sensor. Help please!

You need to make sure all relays are powering up and functional and all the fuses are good before you go any further.

 

All relays and fuses under hood are good. Open circuit relay is good but isn’t getting any power. Not sure what’s going on there

 

You need to trace that down because that relay is very important. Matter of fact, that relay is 100% your issue and I wish I knew that issue was going on sooner because that relay powers EFI.

 

The green and yellow wire to the open circuit is the one not gettin power. Also read the codes. Only getting p0335, crankshaft position sensor a circuit malfunction.

 

Pulled the relay out and tested it. It working perfectly. Plugged it back in and no clicking. No power coming from green and yellow wire. Traced it back to the ecu. Continuity is good tho

 

What exactly tells the ecu to send power out?

 

I might be wrong, but I think you're totally mistaken about the crank and cam sensors not having power. For some reason you are under the assumption that one of the wires should have voltage. Why do you think that?

The standard values at the computer terminals were posted on the first page of this thread. NE is crank position sensor and G is cam position sensor, and it says there is just a pulse generated WHILE IDLING (between NE+ & NE-, G+ & G-). The sensors are just pick-up coils (hall effect sensors) that generate a small voltage when a rotor passes by them.

 

This DTC would indicate the ECU is not picking up the signal the crank position sensor produces. This can be due to defective sensor, defective wiring or harness, etc
The ECU will not fire the truck up unless it detects the correct signal from the crank and cam position sensors.

 

There have been a few valid posts since I started putting this one together and broke for dinner but here goes anyway.

"Not getting power" could apply to the relay coil and/or the circuit contacts.

Look at the "theory of operation" diagram below, work backwards from the ECM at lower right. The "NE" signal comes from the crank position sensor on the 5vz and the cam position sensor on the 3rz. Otherwise the diagram is the same for both engines.

Note the following, all troubleshooting hints.

The CO and EFI relay contact circuits are in series.

The ECM controls the CO relay (ground switched at ECM FC).

The ignition switch controls the EFI relay (positive switched).

The "STA" signal is pulled from the starter relay. The book says anything over 6v. Essentially any level of battery voltage diminished somewhat by the starters heavy draw.

The diagram description below is a bit off. Both the "STA" and the "NE" signal will independently and separately close the CO relay allowing the fuel pump to run. Both signals simultaneously is not required. The "STA" signal initially starts the pump, once the engine is turning the (now present) "NE" signal maintains pump operation when the key is released to "run". Should the engine stop turning for any reason the "NE" signal will drop out and the pump will shut off (safety feature).

The cam and crank sensors are not "powered". They "generate" a 5v "pulse" input to the ECM so it knows what the crank and cams are doing. Speed, position, intake/exhaust stroke orientation and even misfire detection are some of the things the ECM uses the inputs for. It would be tough to get any kind of operating electrical readings from these fellows with out a specialized diagnostic meter/reader with oscilloscope type functions.

 

The open circuit relay is good. I took it out and tested it via the FSM and it was operating as it should. And also checked the power and grounds in the plug in for the OC relay and it was only getting power from the EFI relay wire. The FC wire (green with yellow stripe) didn’t have any voltage to it. Traced it back and checked for voltage for the FC wire at the ECM and it had no voltage coming straight out of the computer. The ignition switch is working properly. All of the underhood relays are working. I’m curious to know which wires are powering the ecu because I want to test that circuit. Also the cam and crank sensor circuit is not powered, no voltage at all going to any of the wires in that circuit

 

Did you check the fuses under the dash?

 

Post #13 has all the values in it for the computer.

 

Wait. You posted you have a crank sensor code. Have you run the diagnostic steps to check it?

 

Any time you have a code that makes the ECM think the engine is not running it will shut the fuel off to the engine it thinks is not running.

I think this may have started as a Poor connection or poor after Market sensors.

Now so many different variables have been added to the mix the problem has gotten worse.

Figure out the crank sensor code issue then go from there.

 

Looks like you missed that the ECM grounds the CO relay coil. The 12v does not come from the ECM, it comes from the EFI relay contact circuit. Check for that, with key on. And again the cam and crank sensors are not "powered".

As mentioned, figure out the crank sensor circuit code. Note that both sensors use a ground point inside the ECM for accurate reference. Sometimes called a reference ground.
I don't have a 97 book but some years this ground point is common or shared by both sensors. Could be common inside the ECM or connected together outside like the diagram below. Meaning if it's open, both sensors will not function and the crank sensor circuit code may have just been the first to trigger (speculation).

Not your year but nearly identical.

 

Crankshaft code. It’s a new sensor

 

I think I’m gonna get another new sensor and see if that is the problem. The one I got is new but could be faulty. Not sure what else to do to figure out that code. Besides everything I’ve done already.

 

This is a new OEM sensor right? Lots of counterfeit knockoffs that even look pretty close to OEM making the rounds through the ebays and the Amazons

 

I got it off rockauto

 

Have you ohm tested the wires from the ecm to the crankshaft sensor plug? Or ohm tested crankshaft sensor?