2003 Tahoe Camshaft Positioning Sensor Codes

Just changed out the plugs the other day. Drove it like 300 miles, no issues. Started it the next day it sets a PO342, PO340 code, (low input, perfomance) Starts a little funky, but starts. Replaced the Cam sensor, still get the code. Check the Red wire out of the connector, didn't quite get batt. voltage. Batt Vol. was 11.93, I got 11.0 volts out of the rRed wire. I got about the same out of the Red and the Black / Pink wire, (I think it's the Black / Pink wire) I couldn't find the Brown / Red wire in the loom to check it to the computer...I'm pissed, I just paid this thing off. Never had ONE issue when I was paying on it.

this problem may be from you being too hard on the wire harness. this/these vehicles have fragile wires. copper is expensive!

what is required is to first inspect connectors C-1/2 of the PCM/computer.

then measure the resistance of the runs to/from the sensor/pcm.

C1-62 is ground to B of sensor,C2-39 to C is 12volts, and C1-73 is sensor sig output A.

with the engine running the battery volts should be 13.75VDC. could be the alternator is shot. that is quite common as the voltage regulators made at this time were defective.

new alternators use the updated regulators more resistant to corrosion.

J Cat,
Thanks for the reply. I don't understand your discription on the connectors. I'm kinda lame on the lingo. Could you explain in laymens terms? Ha....

Really appricate all your efforts!!!

J Cat,
Thanks for the reply. I don't understand your discription on the connectors. I'm kinda lame on the lingo. Could you explain in laymens terms? Ha....

Really appricate all your efforts!!!

the pcm is the computer. C1/C2 is the computer connector number. the pin number is the other number. C1-19 connector 1 pin 19. anyway if the replacement did not fix it the wires are most probable. actually this is not common for the sensor to go bad CAM SENSOR. cranksensors on occation have been reported. wiring is most likely the problem . use ohmmeter to check for bad wires. make sure the connector pins are clean and the gasket is there to protect from corrosion.

JCat,
Which connector on the PCM is which? Does it say somewhere "Connector 1, 2"? How do you determine which pin you are to probe? Are the pins numbered?

JCat,
Which connector on the PCM is which? Does it say somewhere "Connector 1, 2"? How do you determine which pin you are to probe? Are the pins numbered?


the connectors are marked/when the connector is removed you will see numbers next to the pins.

also the pcm should have numbers on it of what connector goes to that recepticle.

REMOVE THE BATTERY NEGATIVE CONNECTION BEFORE DOING THIS !

JCat,
Thanks for all the info....I'll let you know how it all works out. It may be a week before I get to it.

Well I probed the wires between the connector of the camshaft positioning sensor and C1-73, of the computer connector, no continuity. The other 2 wires had continuity. Do I cut the wire near the camshaft positioning sensor and then cut the wire near the computer and put a new wire in? OR should I strip the wire and jumper it just to see what happens?

Well I probed the wires between the connector of the camshaft positioning sensor and C1-73, of the computer connector, no continuity. The other 2 wires had continuity. Do I cut the wire near the camshaft positioning sensor and then cut the wire near the computer and put a new wire in? OR should I strip the wire and jumper it just to see what happens?

use a needle very small dia . and stab the wire[needle connected to meter lead] to locate the open portion. my guess is the open will be close to the connector of either end.

C-1 pin 73 is the sensor signal out . when you find the open point you could jump this with a wire. then solder and seal with liquid tape.

I just found a bunch of new pig tail connectors, hopefully I'll have the right one for the PCM and the camshft sensor connector. I'll replace and see what happens. Thanks for your support, really appricate it.

JCat,
Finally got to it. It's fixed, no codes, no pending codes, runs great. It must have been a broken or damaged wire somewhere in the loom. Out of about 1,000 different pins I have, I couldn't find the right ones for the CPM connector nor the camshaft sensor connector. I removed the pin from the connector on the sensor and reused it. Worked great. On the computer side I cut the wire just long enough to add my new wire.

Thanks for all your help!!:rofl:

JCat,
Finally got to it. It's fixed, no codes, no pending codes, runs great. It must have been a broken or damaged wire somewhere in the loom. Out of about 1,000 different pins I have, I couldn't find the right ones for the CPM connector nor the camshaft sensor connector. I removed the pin from the connector on the sensor and reused it. Worked great. On the computer side I cut the wire just long enough to add my new wire.

Thanks for all your help!!:rofl:

good to here you did thid yourself. you did save a large amount compared to having a repair shop fix this. most likely they would start by replacing all the components PCM etc.

as these vehicles age I am seeing more wiring issues like this. the wires are too small.

GOOD LUCK.

good to here you did thid yourself. you did save a large amount compared to having a repair shop fix this. most likely they would start by replacing all the components PCM etc.

as these vehicles age I am seeing more wiring issues like this. the wires are too small.

GOOD LUCK.

Hopefully Either one of you Respond.

I am having this same problem following the same maintenance.
About 3 Months Back I changed my Plugs and Wires (Not sure if it matters, But i saw SurfingFool21 did the same thing.)

About a Month Ago My Check Engine Light Came on, and My Tahoe Began Starting Rough, but running the same as normal.
I read the Code and got a PO432. "CamShaft Position Sensor Bank 1 Circuit Low"

So I Changed The Cam Shaft Position Sensor Located behind the Intake Manifold. I then Cleared the Code and It came Right Back On and My Tahoe Continued to Start Rough but Run Normal.

I Came across this Thread, and Followed the steps. I Checked Continuity From the PCM to the Camshaft Position Sensor Harness for All Three Wires. In the Brown Wire I Got .5, Black and Pink I Got 1.7 and for The Pink Wire I Got 32.5.
I am under the impression that Sense I Got a reading I have Continuity.

I Put Everything back together and Started Her up, Fired Right Up. I pulled it out of my garage, Drove about a mile brought it back, Turned it off and on quite a few Times, no check engine light. Started right up every time.
About an Hour later I went back tried to start it and it was hard again. It started up and the check engine light was back on. And the hard starting was back. I turned it off and on a bunch of time with intermittent hard starts.

I Don't know what else to do. Any help and/or suggestions would be Amazing , this is driving me nuts, and any shop will probably charge me a boat load in Diagnostic a parts.

Thank You In Advance!!!!:banghead:

***I have an 03 Chevy Tahoe LT

Code is Actually PO342

do the voltage readings again. follow the instructions given. use the connector pins ID to report any readings. also you must make sure the meter ground is properly connected to the battery ground.


never use any test lights ! when the signal lost is found then trace that wire back to locate the open which is most likely near the PCM. could also be corroded connector at the pcm. disconnect battery ground before messing with any connector removals.

Thank You for the quick response!!


I did Voltage Readings on the Plug with the Vehicle running.

C1-61=.2-.3 Volts

C2-39=13.67 Volts

C1-73=.2-.3 Volts

Last Night When I checked Resistance

C1-61=.4 Ohms

C2-39=32.5 Ohms

C1-73=1.4 Ohms

c1-62 is ground. should be no voltage. check with ohm meter that this is going to ground.

I have Continuity From Ground at CSPS Plug To Ground.

I have Continuity From Ground at CSPS Plug To Ground.

with the readings I would say the sensor is not creating a signal. you are at the sensor , engine on . and measuring the output signal correct. ? measure at sensor from the ground wire to the output signal wire see what voltage is .

with the readings I would say the sensor is not creating a signal. you are at the sensor , engine on . and measuring the output signal correct. ? measure at sensor from the ground wire to the output signal wire see what voltage is .

I am At the Sensor, Car On, Measuring output Signal. Ill Check Ground to Output as soon as I can.

Do think it is at all Weird that I Read 32.5 Resistance in the 12 volt wire From PCM-Plug
Also is it normal that The Car runs As usual but starts Hard?

I am At the Sensor, Car On, Measuring output Signal. Ill Check Ground to Output as soon as I can.

Do think it is at all Weird that I Read 32.5 Resistance in the 12 volt wire From PCM-Plug
Also is it normal that The Car runs As usual but starts Hard?

with the PCM plug disconnected from the pcm and you measure the resistance from the pcm end to the sensor end the resistance should be zero or very low ohms. is that what you did ?

with the PCM plug disconnected from the pcm and you measure the resistance from the pcm end to the sensor end the resistance should be zero or very low ohms. is that what you did ?

Yes, I followed the Instructions you gave SurfingFool21.

C1-62-.4
C2-39-32.5
C1-73-1.4

Yes, I followed the Instructions you gave SurfingFool21.

C1-62-.4
C2-39-32.5
C1-73-1.4


I checked Again and Realized i was checking C1-39, it was the wrong wire.

I have Normal Continuity in all 3 wires, I Removed the CSPS and Reinstalled it.
Still the same thing.

Ive Run out of ideas.

I checked Again and Realized i was checking C1-39, it was the wrong wire.

I have Normal Continuity in all 3 wires, I Removed the CSPS and Reinstalled it.
Still the same thing.

Ive Run out of ideas.

the connectors at the pcm should be checked for corrosion.

so now you have found the correct wires see if you get at the pcm what you get at the sensor. use a needle to probe the wire .

when its done use liquid tape to seal the punctures.