LS2 Swap and throwing P0343 code...
10-07-2011, 08:41 AM
#1
LS2 Swap and throwing P0343 code...
Alright guys/girls, looking for some help in trying to diagnose this problem. I have a 2002 GMC RCSB and I did a LS2 swap. Now when I fire it up I throw the P0343 code which is a high input on the cam sensor. I have already changed the sensor out and it still throws the code. The engine fires up fine sometimes and other times its spins for awhile and back fires through the exhaust. Any ideas would be greatly appreciated.
10-17-2011, 12:17 PM
#4
Alright guys/gals, I switched the wires on the katech ext. harness and I'm still getting the same code and problems. Does anyone else have a clue what I could do, its annoying that my truck looks like a piece of junk cuz it won't start?
11-29-2011, 11:25 AM
#8
DTC P0343
Circuit Description
The camshaft position (CMP) sensor works in conjunction with a 1 X reluctor wheel on the camshaft. The powertrain control module (PCM) provides a 12-volt reference to the CMP sensor as well as a low reference and a signal circuit.
The CMP sensor determines whether a cylinder is on a firing stroke or on an exhaust stroke. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The sensors internal circuitry detects this and produces a signal which the PCM reads. The PCM uses this 1 X signal in combination with the crankshaft position (CKP) sensor 24 X signal in order to determine CKP and stroke. This diagnostic for the CMP sensor checks for a loss of CMP sensor signal.
As long as the PCM receives the CKP sensor 24 X signal, the engine will start. The PCM can determine top dead center (TDC) for all cylinders by using the CKP sensor 24 X signal alone. The CMP sensor 1 X signal is used by the PCM to determine if the cylinder at TDC is on the firing stroke, or the exhaust stroke. The system attempts synchronization and looks for an increase in engine speed indicating the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes the PCM incorrectly synchronized to the exhaust stroke and re-syncs to the opposite cam position. A slightly longer cranking time may be a symptom of this condition.
Conditions for Running the DTC
The engine speed is less than 4,000 RPM.
Conditions for Setting the DTC
The PCM detects the CAM signal is stuck high when the signal should be low for 1.5 seconds.
Diagnostic Aids
The following conditions may cause this DTC to set:
• Camshaft reluctor wheel damage
• The sensor coming in contact with the reluctor wheel
Using Freeze Frame/Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass or a fail. Operate the vehicle within the same Freeze Frame conditions such as RPM, load, vehicle speed, temperature, etc. that you observed. This will isolate when the DTC failed.
The CMP sensor output can be tested. The sensor must be supplied with a power and a ground. The engine must be cranking to perform this test. You can measure the duty cycle at the signal circuit of the sensor. The duty cycle should be between 45–55 percent for a good sensor.
1. Connect a scan tool.
2. Start the engine.
3. Use the scan tool in order to monitor the CMP signal input high-to-low and low-to-high transition parameter.
Does the scan tool parameter increment? YES or NO
Circuit Description
The camshaft position (CMP) sensor works in conjunction with a 1 X reluctor wheel on the camshaft. The powertrain control module (PCM) provides a 12-volt reference to the CMP sensor as well as a low reference and a signal circuit.
The CMP sensor determines whether a cylinder is on a firing stroke or on an exhaust stroke. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The sensors internal circuitry detects this and produces a signal which the PCM reads. The PCM uses this 1 X signal in combination with the crankshaft position (CKP) sensor 24 X signal in order to determine CKP and stroke. This diagnostic for the CMP sensor checks for a loss of CMP sensor signal.
As long as the PCM receives the CKP sensor 24 X signal, the engine will start. The PCM can determine top dead center (TDC) for all cylinders by using the CKP sensor 24 X signal alone. The CMP sensor 1 X signal is used by the PCM to determine if the cylinder at TDC is on the firing stroke, or the exhaust stroke. The system attempts synchronization and looks for an increase in engine speed indicating the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes the PCM incorrectly synchronized to the exhaust stroke and re-syncs to the opposite cam position. A slightly longer cranking time may be a symptom of this condition.
Conditions for Running the DTC
The engine speed is less than 4,000 RPM.
Conditions for Setting the DTC
The PCM detects the CAM signal is stuck high when the signal should be low for 1.5 seconds.
Diagnostic Aids
The following conditions may cause this DTC to set:
• Camshaft reluctor wheel damage
• The sensor coming in contact with the reluctor wheel
Using Freeze Frame/Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass or a fail. Operate the vehicle within the same Freeze Frame conditions such as RPM, load, vehicle speed, temperature, etc. that you observed. This will isolate when the DTC failed.
The CMP sensor output can be tested. The sensor must be supplied with a power and a ground. The engine must be cranking to perform this test. You can measure the duty cycle at the signal circuit of the sensor. The duty cycle should be between 45–55 percent for a good sensor.
1. Connect a scan tool.
2. Start the engine.
3. Use the scan tool in order to monitor the CMP signal input high-to-low and low-to-high transition parameter.
Does the scan tool parameter increment? YES or NO
