2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1278
4. Install the fuse that supplies B+ to terminal 56-X2 of the ECM.
5. Ignition ON, test for greater than 4.8 V between the 5-volt reference circuit terminal 3 and the low reference circuit terminal 1.
瀚慖f less than the specified value, test for an open/high resistance in the 5-volt reference circuit. If the circuits/connections test normal,
replace the ECM.
6. Test for 4.8-5.2 V between the signal circuit terminal 2 and ground.
瀚慖f the voltage is greater than specified range, test for a short to voltage in the signal circuit. If circuit/connections test normal, replace the
ECM.
瀚慖f the voltage is less than the specified range, test for a short to ground or an open/high resistance in the signal circuit. If
circuit/connections test normal, replace the ECM.
7. If all circuits/connections test normal, test or replace the crankshaft position sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Crankshaft Position Sensor Replacement (See: Powertrain Management/Computers and Control Systems/Crankshaft Position
Sensor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
programming
P0336
DTC P0335, P0336, or P0338 (LAU)
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 P0335
- Crankshaft Position Sensor Circuit
DTC P0336
- Crankshaft Position Sensor Performance
DTC P0338
- Crankshaft Position Sensor Circuit High Duty Cycle
Diagnostic Fault Information
Circuit/System Description
The crankshaft position sensor is located on the rear of bank 1 of the engine block. The crankshaft position sensor is a hall effect switch that works
in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel is spaced 6 degrees apart with one span
having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center (TDC) for cylinders 1 and 4.
The ECM determines when cylinder 1 is on the compression stroke by monitoring the crankshaft position sensor and the camshaft position sensors.
The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the crankshaft position sensor and the
camshaft position sensor inputs.
Conditions for Running the DTC
