DTC P0340 or P0345. Cadillac STS 2005

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 Engine 🢒 Engine Controls - 4.6L (LH2) 🢒 DTC P0340 or P0345

Circuit Description

The intake camshaft position (CMP) sensor is a hall integrated circuit (IC) type sensor that works in conjunction with an 8-tooth reluctor wheel used to determine the position of the intake camshaft. The engine control module (ECM) supplies a 12-volt pull up voltage on the CMP sensor signal circuit. As the teeth on the reluctor wheel passes the CMP sensor, it sends a digital signal which is an image of the reluctor wheel to the ECM. The ECM processes this information to determine the exact position of the camshafts, and to determine the optimum ignition and injection points of the engine. The CMP sensor wiring consists of a 12-volt reference circuit, a low reference circuit, and a signal circuit. If the ECM cannot see a change in the intake CMP sensor signal, DTC P0340 or P0345 will set.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

•	DTC P0340 Intake Camshaft Position (CMP) Sensor Circuit Bank 1

•	DTC P0345 Intake Camshaft Position (CMP) Sensor Circuit Bank 2

Conditions for Running the DTC

•	The engine is running.

•	DTC P0340 or P0345 runs continuously when the above condition is met.

Conditions for Setting the DTC

The ECM does not detect a signal from the intake CMP sensor for more than 1 second.

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 3 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

•	The following conditions may cause this DTC to set:

-	Damage to the camshaft reluctor wheel

-	Damage to the CMP sensor

-	The sensor coming in contact with the reluctor wheel

-	Foreign material passing between the sensor and the reluctor wheel

•	If the condition is intermittent, refer to Intermittent Conditions .

Test Description

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

This step verifies that the condition is present.

This step determines if the signal circuit is shorted to voltage. A normal operating signal circuit will not illuminate a test lamp.

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

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 3

Go to Diagnostic Aids

Turn OFF the ignition.
Disconnect the affected intake camshaft position (CMP) sensor.
Turn ON the ignition, with the engine OFF.
Probe the 12-volt reference circuit with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

Turn OFF the ignition.
Jumper the CMP circuits from the CMP sensor to the CMP sensor harness connector. Refer to Using Connector Test Adapters in Wiring Systems.
Turn ON the ignition, with the engine OFF.
Measure the voltage drop from the low reference circuit of the CMP sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage more than the specified value?

0.2 V

Go to Step 9

Go to Step 5

Turn OFF the ignition.
Remove the jumper wires from the CMP sensor.
Turn ON the ignition, with the engine OFF.
Measure the voltage from the CMP sensor signal circuit to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage greater than the specified value?

11 V

Go to Step 6

Go to Step 10

Probe the CMP sensor signal circuit with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

Go to Step 11

Go to Step 7

Turn OFF the ignition.
Disconnect the engine control module (ECM).
Measure the resistance of the CMP sensor signal circuit. Refer to Circuit Testing in Wiring Systems.

Is the resistance more than the specified value?

5 ohms

Go to Step 12

Go to Step 13

Test the 12-volt reference circuit for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 14

Test the low reference circuit for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 14

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

Did you find and correct the condition?

Go to Step 18

Go to Step 14

Test the signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 14

Repair the high resistance in the signal circuit of the CMP sensor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 18

Test for an intermittent and for a poor connection at the CMP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 15

Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 17

Remove the CMP sensor. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake or Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake .
Visually inspect the CMP sensor for the following conditions:

•	Physical damage

•	Loose or improper installation

Did you find and correct the condition?

Go to Step 18

Go to Step 16

Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake or Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake .

Did you complete the replacement?

Go to Step 18

Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 18

Clear the DTCs with a scan tool.
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 2

Go to Step 19

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK