03 5.3 ignition schematic?

[NITROUS]

I was thinking that also Greg but you can unplug the cam sensor and the vehicle still run since the PCM uses the CKP and it has to be functioning since the plugs are wet. Look at the PCM and make sure the pin that triggers the coils works and also make sure you can read RPM with a scanner. If you can't see RPM something else is wrong.

[RedHeartbeat]

An incompatible throttle pedal module won't let it fire either.

[NITROUS]

I think they'd see a DTC if that was the case unless no MIL light is checked.

[LSXmyford]

yep, first post.

new cam and crank sensor.



ok fellas, ease up a little.

Lets knock things out one at a time.

to make things easier for me to process, could you quote my messages, and break them down, responding to each section individually? Id appreciate it.

When you says system voltage, it would be correct for me to think that would be voltage from battery + to ground, correct?

if yes, then the cam and crank ground wires are off alot, which would mean ground correct? Im 30mi away and hes taking care of things, so he wont be able to double check the two harness grounds until later this evening.


this engine came out of a wrecked vehicle, so it ran for sure up until it ran off the road. allegedly, it was driven around the shop that my bro purchased it from.

engine is bone stock.


throttle pedal sensor is new, remember it was throwing a code for this, so it was replaced, now no codes.




id like to throw this out there again.
when he tested the four wires at the coil, one was 11.4 volts roughly, one was a ground, two were dead as a hammer with or without key on, did not test with cranking engine, should he? again, resistance from coil packs to pcm were tested and confirmed ok.


is there another way to read rpm, he just has a basic scanner tool. could he connect the multimeter, set on ohms to the rpm wire? I have no idea, just speculating?



know off the top of your head which pin signals the coils, what voltage should he see, should it be intermitant, Im guessing 5v and yes? he has the pin sheet with what is what, just wanna double check.

[LSXmyford]

should add. he purchased a new coil pack, checked for spark. nada.
he is using the newly programmed pcm.

[gmc6]

this might help you out.

[LSXmyford]

thanks

it points out the specific wires and colors...should help.

[KySilverado]

Damn this would be much easier if photobucket would coop.

Cam Sensor
Brn/white - CMP sensor signal
PNK/Black - Low reference
Red - 12v reference

CKP
Dk Blue/White - Sensor signal
Yellow/Black - Low ref
Lt. Grn - 12v ref

[KySilverado]

Only thing I've found for testing the CKP wiring .

1. Turn ON the ignition, with the engine OFF.
2. Disconnect the crankshaft position (CKP) sensor.
3. Measure the voltage from the CKP sensor 12-volt reference circuit and a good ground with the DMM.
4. Compare the measured voltage with the system voltage.

Is the difference in the voltage more than the specified value?
0.5 V

[468Blazer]

Hope this helps somewhat.

Camshaft Position sensor
Brn/White-CMP Sensor Signal-Checked at C1 Pin 73--Flucuates from 0-10.4 volts when cranking
PNK/BLK-Low Reference-Checked at C1 Pin 61--No voltage with crank or not
RED-12 Volt Reference-Checked at C2 Pin 39--11.44 Volts

Crankshaft Position Sensor
DK BLU/WHT-CKP Sensor Signal-Checked at C1 Pin 12--Flucuates from 0-10 volts when cranking
YEL/BLK-Low reference-checked at C1 Pin 21--No voltage with crank or not
LT GRN-12 Volt Reference-Checked at C1 Pin 2--11.4 volts

I also checked the other PINS for the "low reference" and recieved no voltage.
Checked the wires that are a 5 volt reference and get 5 volts exactly.

What I'm thinking if the low reference wasn't recieving anything through the crankshaft position then wouldn't that kill all "low references from getting anything since the CKP is what is needed to start.
I totally understand the "new" CKP sensor could be bad. Could I take the sensor itself out and test the leads for resistance and what should they be?
Travis