2010 Cadillac Truck SRX FWD V6-3.0L Page 1480

2010 Cadillac Truck SRX FWD V6-3.0L Page 1480

P0391

DTC P0341, P0346, P0366, or P0391 (LF1)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0341

- Intake Camshaft Position Sensor Performance Bank 1

DTC P0346

- Intake Camshaft Position Sensor Performance Bank 2

DTC P0366

- Exhaust Camshaft Position Sensor Performance Bank 1

DTC P0391

- Exhaust Camshaft Position Sensor Performance Bank 2

Diagnostic Fault Information

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. This information is then used to determine the optimum ignition and

injection points of the engine. 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, to control camshaft

phasing, and for limp-home operation.

Conditions for Running the DTC

* DTCs P0335, P0336, P0641, P0651, or P0697 are 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 engine has started, but has received either of the following during the first engine revolution:

- Less than or more than 4 camshaft position sensor pulses, if equipped with an automatic transmission

- Less than 4 or more than 8 camshaft position sensor pulses, if equipped with a manual transmission

* The ECM detects that the engine is running, but receives less than 398 camshaft position or more than 402 camshaft position sensor pulses

per 100 engine cycles in 800 of 1000 engine cycles.

Action Taken When the DTC Sets