DTC P0343, P0348, P0368, or P0393. Cadillac STS 2005

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 Engine 🢒 Engine Controls - 3.6L (LY7) 🢒 DTC P0343, P0348, P0368, or P0393

Circuit Description

Each camshaft is equipped with a camshaft position (CMP) sensor that the engine control module (ECM) monitors. The CMP sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the CMP sensor signals in order to determine the position of the camshafts.

The ECM supplies 5 volts to the CMP sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The CMP sensors provide a signal to the ECM on the signal circuits. If the ECM detects the CMP signal voltage is more than a predetermined voltage, within a certain number of crankshaft revolutions, this DTC sets.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

•	DTC P0343 Intake Camshaft Position (CMP) Sensor Circuit High Voltage Bank 1

•	DTC P0348 Intake Camshaft Position (CMP) Sensor Circuit High Voltage Bank 2

•	DTC P0368 Exhaust Camshaft Position (CMP) Sensor Circuit High Voltage Bank 1

•	DTC P0393 Exhaust Camshaft Position (CMP) Sensor Circuit High Voltage Bank 2

Conditions for Running the DTC

•	The engine is operating.

•	DTCs P0343, P0348, P0368, P0393 run continuously once the engine is operating.

Conditions for Setting the DTC

The CMP sensor signal voltage is always high and the ECM detects no pulses from the CMP sensor for more than 4 seconds.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

•

The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

•	The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail.

•	A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

•	A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

•	Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

•	Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.

•	The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views .

•	For an intermittent condition, refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step determines that the condition is present.

This step tests the signal circuit of the CMP sensor. This circuit is pulled-up to about 5 volts.

The ECM produces a measurable steady-state amperage that provides the 5-volt reference to the CMP sensors. If the amperage on the 5-volt reference circuit is less than the specified value , test for a condition in the 5-volt reference circuit.

This step tests for high resistance in the low reference circuit of the CMP sensors. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

Important: If DTC P0118 also sets, refer to DTC P0118 .

Turn ON the ignition, with the engine OFF.
Clear the diagnostic trouble codes (DTCs) with a scan tool.
Start the engine.
Observe the DTC information with a scan tool.

Does the scan tool indicate that DTC P0343, P0348, P0368, or P0393 failed this ignition?

Go to Step 4

Go to Step 3

Observe the Freeze Frame/Failure Records for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 4

Go to Diagnostic Aids

Turn OFF the ignition.
Disconnect the appropriate camshaft position (CMP) sensor connector.
Turn ON the ignition, with the engine OFF.
Measure the voltage between the signal circuit of the CMP sensor and the engine control module (ECM) housing with a DMM.

Is the voltage within the specified range?

4.5-5.5 V

Go to Step 5

Go to Step 7

Set up a DMM to test amperage on the 400 mA scale.
Measure the amperage from the 5-volt reference circuit of the CMP sensor to the ECM housing.

Is the amperage more than the specified value?

80 mA

Go to Step 6

Go to Step 8

Turn OFF the ignition.
Remove the ECM/TCM fuse from the underhood electrical center.

Notice: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.

Measure the resistance between the low reference circuit of the CMP sensor and the ECM housing with a DMM.

Is the resistance less than the specified value?

5 ohms

Go to Step 10

Go to Step 9

Test the signal circuit of the CMP sensor for an open or for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.