Diagnostic Aids

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

An intermittent CKP sensor signal may cause DTC P0336 to set. Wiggle the wiring harness with the engine running and observe the CKP Signal Missed parameter of the scan tool. If the parameter indicates anything other than 0, there is an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections and Inducing Intermittent Fault Conditions in Wiring Systems.
A short from the 12-volt reference circuit to the Low reference circuit internally in the camshaft position (CMP) or crankshaft position (CKP) sensor can cause all three DTCs P0336, P0340, and P1345 to set.

DTC P0336

Step	Action	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check- Engine Controls?	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	Observe the Freeze Frame/Failure Records data 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
3	Inspect all of the circuits going to the crankshaft position (CKP) sensor for the following: Routed too closely to fuel injection wiring or components Routed too closely to after-market add-on electrical equipment Routed too closely to solenoids, relays, and motors If you find incorrect routing, correct the harness routing. Did you find and correct the condition?	Go to Step 9	Go to Step 4
4	Test for an intermittent and for a poor connection at the CKP 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 9	Go to Step 5
5	Test for an intermittent and for a poor connection of the CKP sensor circuits at the engine control module (ECM). Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 9	Go to Step 6
6	Remove the CKP sensor. Refer to Crankshaft Position (CKP) Sensor Replacement . Visually inspect the CKP sensor for the following conditions: Physical damage Loose or improper installation Wiring routed too closely to secondary ignition components The following conditions may cause this DTC to set: Excessive air gap between the CKP sensor and the reluctor wheel Electromagnetic interference in the CKP sensor circuits Foreign material passing between the CKP sensor and the reluctor wheel Insufficient fuel Did you find and correct the condition?	Go to Step 9	Go to Step 7
7	Inspect the CKP reluctor wheel for the following conditions: Physical damage Improper installation Excessive endplay or looseness Refer to Crankshaft Reluctor and Oil Pump Drive Gear Replacement in Engine Mechanical-6.6L. Did you find and correct the condition?	Go to Step 9	Go to Step 8
8	Replace the CKP sensor. Refer to Crankshaft Position (CKP) Sensor Replacement . Did you complete the replacement?	Go to Step 9	-
9	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 10
10	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	Go to Diagnostic Trouble Code (DTC) List	System OK