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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 XLR 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC P0340, P0341, P0345, P0346, P0365, P0366, P0390, or P0391

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

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

DTC P0341: Intake Camshaft Position (CMP) Sensor Performance Bank 1

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

DTC P0346: Intake Camshaft Position (CMP) Sensor Performance Bank 2

DTC P0365: Exhaust Camshaft Position (CMP) Sensor Circuit Bank 1

DTC P0366: Exhaust Camshaft Position (CMP) Sensor Performance Bank 1

DTC P0390: Exhaust Camshaft Position (CMP) Sensor Circuit Bank 2

DTC P0391: Exhaust Camshaft Position (CMP) Sensor Performance Bank 2

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference Circuit

P0069, P0107, P0340, P0345, P0365, P0390, P0452, P0522, P0532, P0641, P1183, P2228

P0340, P0345, P0365, P0390

P0641

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CMP Sensor Signal Circuit

P0340, P0345, P0365, P0390

P0340, P0345, P0365, P0390

P0340, P0345, P0365, P0390

P0341, P0346, P0366, P0391

Low Reference Circuit

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P0340, P0345, P0365, P0390

P0340, P0345, P0365, P0390

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Circuit/System Description

The 4X camshaft position (CMP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit, and an output signal circuit. The CMP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the CMP sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with 2 narrow, and 2 wide output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the CMP sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition timing and fuel injection points of the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control the CMP actuator if equipped, and for limp-home operation.

Conditions for Running the DTC
    • The engine is running.
    • DTC P0641 or P0651 are not set.
    • The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

P0340, P0345, P0365, P0390

    • The ECM detects that the starter is commanded on and the engine has been cranking, and rotation detected, for more than 4 seconds without a CMP sensor pulse.
    • The ECM detects that the engine is rotating, but did not received a CMP sensor pulse during the first 100 engine cycles.
    • The ECM detects that the engine is running but did not receive a cam sensor pulse for 3 seconds.
    • The ECM detects that the engine is rotating but did not receive a CMP sensor pulse during any 100 engine cycles.

P0341, P0346, P0366, P0391

    • Less than 4 or more than 10 CMP sensor pulses during the first 2 engine revolutions.
    • The ECM detects that the engine is running, but receives approximately 400 CMP pulse per 200 engine cycles.

Action Taken When the DTC Sets
    • DTCs P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391 are Type B DTCs.
    • The CMP actuator is commanded to the parked position.
    • A fault on one intake CMP sensor will park both intake camshaft actuators. A fault on one exhaust CMP sensor will park both exhaust camshaft actuators.

Conditions for Clearing the DTC

DTCs P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391 are Type B DTCs.

Diagnostic Aids

With a DTC set, the engine may crank for an extended period of time during start-up.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Description and Operation

Electronic Ignition (EI) System Diagnosis

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Special Tools Required

J 35616 Connector Test Adapter Kit

Circuit/System Verification
  1. Ignition OFF, inspect the engine wiring harness carrying the CMP sensor circuits for the following conditions:
    2. • Close routing of aftermarket electrical equipment
    • Close to solenoids, motors, and relays
         ⇒Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  2. Observe that the following parameters are all incrementing:
    3. • Exhaust CMP bank 1 active
    • Intake CMP bank 1 active
    • Exhaust CMP bank 2 active
    • Intake CMP bank 2 active
    ⇒If the vehicle passes the Circuit/System Verification Test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records data list.
  3. Engine running, observe the DTC information with a scan tool. DTCs P0340, P0341, P0345, P0346, P0365, P0366, P0390, or P0391 should not set.
  4. 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 data.

Circuit/System Testing

P0340, P0345, P0365, P0390

  1. Ignition OFF, disconnect the appropriate camshaft position (CMP) sensor wire harness connector.
  2. Test for less than 1 ohm of resistance on the CMP low reference circuit, from the CMP sensor harness connector terminal B, and ground.
    3. ⇒If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, test for 4.8-5.2 volts on the CMP 5-volt reference circuit, from the CMP sensor harness connector terminal A and ground.
    4. ⇒If less than the specified range, test the 5-volt reference circuit for an open/high resistance or short to ground. If the circuit test normal, replace the ECM.
    ⇒If greater than the specified range, test the 5-volt reference circuit for short to voltage. If the circuit tests normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts on the CMP signal circuit, from the CMP harness connector terminal C and ground.
    5. ⇒If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
    ⇒If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  5. Ignition OFF, connect a fused jumper wire to the CMP signal circuit terminal C, on the CMP sensor harness connector.
  6. Ignition ON, momentarily touch the other the other end of the fused jumper wire to the battery negative post. The CMP active counter parameter on the scan tool, should increment with each individual grounding to the battery negative post.
    7. ⇒If the CMP active counter increments, replace the CMP sensor.
    ⇒If the CMP active counter does not increment, replace the ECM.

P0341, P0346, P0366, P0391

  1. Ignition OFF, inspect the CMP sensor for correct installation.
    2. ⇒If the CMP sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary.
  2. Inspect the engine for the following conditions:
    3. • Engine oil for debris
    • Camshaft reluctor wheel for damage
    • The timing chain, tensioner and sprockets for wear or damage
    ⇒If debris is found in the engine oil, inspect the internal engine components to determine the root cause. Repair or replace any worn or damaged components.

Component Testing

Important: You must perform the Circuit/System Testing before proceeding with Component Testing.

  1. Inspect the CMP sensor for correct installation. Remove the CMP sensor from the engine and inspect the sensor O-ring for damage.
    2. ⇒If the sensor is loose, incorrectly installed, or damage, replace the CMP sensor.
  2. Connect the CMP sensor harness connector to the CMP sensor.
  3. Ignition ON, engine OFF. Observe the CMP Active Counter parameter on the scan tool.
  4. Pass a flat steel object repeatedly across the tip of the sensor that faces the reluctor wheel. The CMP Active Counter parameter should increment with each pass of the steel object.
    5. ⇒If the parameter does not increment, replace the CMP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust
    •  Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake
    •  Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust
    •  Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake
    •  Control Module References for ECM replacement, setup, and programming