2001 Tahoe P0342 [SOLVED]

[whitehoe01]

Ive had a p0342 for a little while. Just got the camshaft sensor changed and the code hasn't gone anywhere.
Reset the code and it instantly post as pending.
bought a new harness and replaced It. The prior wiring wasn't done well. My wiring has been crimped and is nice and tight.
The p0342 code remains. I don't know what the issue is. Can someone please help!

 

[OR VietVet]

Based off of what I just read maybe a problem with the reading of the camshaft itself.

Possible causes

- Faulty Camshaft Position Sensor
- Camshaft Position Sensor harness is open or shorted
- Camshaft Position Sensor circuit poor electrical connection
- Faulty starter motor
- Starting system circuit
- Dead (Weak) battery
Help with this

Tech notes

Sometimes and in some models, low battery voltage or a weak starter can can trigger a Camshaft Position Sensor code.

Help with this

When is the code detected?

The camshaft position sensor signal is sent the Powertrain Control Module (PCM) is too low

Symptoms

- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/Loss of Power
- Engine Stall

P0342 GMC Description

The Camshaft Position Sensor is an electronic device used in an engine to record the rate at which the camshaft is spinning. This information is used by the Engine Control Module(ECM) to control ignition and fuel injection. The camshaft position sensor senses the retraction of camshaft (intake) to identify a particular cylinder. The camshaft position sensor senses the piston position. The sensor system consists of a rotating part, typically a disc, as well as a static part, the actual sensor.
When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change. The changing gap causes the magnetic field near the sensor to change. The change in the magnetic field cause the voltage from the sensor to change.
When the crankshaft position sensor (POS) system becomes inoperative, the camshaft position sensor provides various controls of engine parts instead, utilizing timing of cylinder identification signals.

 

[SLCHOE]

P0342 CMP Sensor Circuit Low Voltage

It is almost definitely a problem with the CAM sensor wiring (or possibly also while VERY rare a problem with the PCM itself) since you have a new CMP.

So disconnect your CMP. Turn the Key On Engine Off.

Take a multimeter and check pin C (Red wire) for 12V. If OK, Check Pin B (Pink with Black stripe) for ~5 Volts. If OK Check Pin A (Brown with White stripe) a short to ground (Very low Ohms).

 

[whitehoe01]

I'll check with my dmm today. I had the engine swapped back in October. Cylinder 7 on my old engine had very low compression.
So after the engine swap I drove the truck home to find out a code popped up. When I read it it was the p0342. The mechanic said it could have been due to the weak battery I had at the time
I wasn't driving the truck b/c I travel for a living and my company gives me rentals.

So now that I'm getting ready to move I decided to go ahead and fix the problem. Went to autozone and bought a new sensor. Swapped it yesterday and the truck is running much better. . Have a brand new northstar agm battery under the hook and a 370amp mechman alternator. Battery rest at 12.9 and with the truck on voltage is around 14.7 so I know its not a weak battery issue as mentioned in the first comment...

while changing everything last night I noticed duct tape.. not factory loom... the wires were twisted together, no solder or a butt connector crimped or anything so I automatically thought that was the issue. Got 3 butt connectors and crimped them rather than leaving twisted wires and duct tape...
I few times it's started right up other times it was a rough start damn near stalling.
I hope they didn't mess something up further up in the harnes. I'll inspect a bit once the sun is up

 

[whitehoe01]

Voltage on the red is 10.57
Pink with brown is only showing 0.02

So I'll go buy thr wire and replace it

---------- Post added at 10:49 AM ---------- Previous post was at 10:26 AM ----------

is there a specific fuse or relay involved as well? I just want to have everything in order

 

[whitehoe01]

Cut the harness off and tested the red wire itself. Its at 10.76 No higher with the key on... is that good enough or is something wrong with the pcm?

 

[SLCHOE]

Cut the harness off and tested the red wire itself. Its at 10.76 No higher with the key on... is that good enough or is something wrong with the pcm?

Red wire should read whatever the battery voltage is. If your battery also reads the same then its good. If it's lower then you have a high resistance somewhere in the circuit dropping that difference in voltage.

Pink/black should be low reference voltage so ~5 volts. If you get nothing, try backprobing that wire at the PCM.

 

[Chevyman95]

Did you ever get this figured out?

 

[flintman]

Red wire should read whatever the battery voltage is. If your battery also reads the same then its good. If it's lower then you have a high resistance somewhere in the circuit dropping that difference in voltage.

Pink/black should be low reference voltage so ~5 volts. If you get nothing, try backprobing that wire at the PCM.

on a multimeter as the frequency is too high.

New to the site but love my Chevy/GMC trucks, long time mechanic but HVAC engineer by trade, I need to dig into a cam sensor issues on an 05 Tahoe, I did replace the sensor for multi cam sensor codes and now only have a PO342. I did check for power and seems good(battery voltage) but need to load test the wires as may not have good voltage under load. Do you you know if pink/black is grounded on the block or does it go back to the PCM and what you reference above is that correct? I do have a scope and will check out the data line as well. I did notice playing around with the wires at the rear of the block I had my oil pressure gauge that always displayed over 80 psi (thought the gauge was junk) but it now works moving around the wires and I'm curious if it uses the same ground, either that, I have some broken or almost broken wires in the sleeve, which I love diggin into. One last thing, Does anyone have the full pin out of the PCM?

 

[Fless]

Wiring diagrams are on charm.li. See below for an example of where to find the cam sensor diagram, but verify your vehicle info when you get there.

The link A Wiring Diagram Index under the Powertrain Management link is a key to which diagram has the cam sensor wiring. You can also use the very first link to look up your code and follow the diagnostic path.

https://charm.li/Chevrolet/2005/Tahoe%202WD%20V8-5.3L%20VIN%20T/Repair%20and%20Diagnosis/

 

[flintman]

Wiring diagrams are on charm.li. See below for an example of where to find the cam sensor diagram, but verify your vehicle info when you get there.

The link A Wiring Diagram Index under the Powertrain Management link is a key to which diagram has the cam sensor wiring. You can also use the very first link to look up your code and follow the diagnostic path.

https://charm.li/Chevrolet/2005/Tahoe%202WD%20V8-5.3L%20VIN%20T/Repair%20and%20Diagnosis/

View attachment 471283

Thanks yes fixing a wiring issue without a diagram is like trying to get to a place without a map, i guess now google maps lol Thanks again

 

[flintman]

After load testing all the wires I found the ground was broken. Used a toner and about 3 inches back from the sensor the wire was broken inside the coating. That was a pain to to put a new harness with the manifold on but I did. Ended up heat shrink and solder. No more code. Thank for the website. Had what I needed.