2010 Cadillac Truck SRX FWD V6-3.0L Page 1472

2010 Cadillac Truck SRX FWD V6-3.0L Page 1472

Circuit/System Description

The 4X camshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an

output signal circuit. The camshaft position 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 camshaft position 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 4 varying width output pulses per camshaft revolution that represent

an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of the camshaft. The ECM

decodes the narrow and wide tooth pattern to identify camshaft position. The ECM uses the cylinder 1 intake camshaft position sensor to determine

injector and ignition system synchronization. Also, the cylinder 1 intake camshaft position sensor is used to determine camshaft to crankshaft

relationship. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses camshaft

position sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and for limp-home

operation.

Conditions for Running the DTC

Note: The ECM detects engine movement by sensing the airflow through the MAF sensor when airflow is greater than 3 g/s, or by sensing

crankshaft position sensor pulses.

* DTC P0102, P0103, P0335, P0336, P0641, P0651, or P0697 is not set.

* The engine is cranking or running.

* The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

* The ECM detects that the starter is commanded ON and the engine has been cranking for more than 4 seconds without a camshaft position

sensor pulse.

* The ECM detects that the engine has started, but did not receive a camshaft position sensor pulse during the first engine revolution.

* The ECM detects that the engine is running, but does not receive a camshaft position sensor pulse for 800 of 1,000 engine cycles.

Action Taken When the DTC Sets

* DTCs P0340, P0345, P0365, and P0390 are Type B DTCs.

* The camshaft position actuator is commanded to the Home or Parked position.

Conditions for Clearing the MIL/DTC

DTCs P0340, P0345, P0365, and P0390 are Type B DTCs.

Diagnostic Aids

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

* The cylinder 1 intake camshaft position sensor is used for injector and ignition system synchronization. A stalling condition will occur if the

CMP sensor signal is intermittent and a DTC will not set. Inspect all cylinder 1 intake camshaft position sensor circuits for poor connections.

Reference Information

Schematic Reference

Engine Controls Schematics (LAU) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics

(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)

Description and Operation

Electronic Ignition System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Electronic

Ignition System Description)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit