• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
5-Volt Reference Circuit | P0651 | P0335 | P0651, P2135 | -- |
CKP Sensor Signal Circuit | P0335 | P0335 | P0335 | P0336 |
Low Reference Circuit | -- | P0335 | P0335 | -- |
The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes between the peaks and valleys of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to sequence the ignition timing and fuel injection events for the engine. The ECM also uses CKP sensor output information to determine the crankshaft relative position to the camshaft, to detect cylinder misfire, and to control the CMP actuator if equipped.
• | DTC P0340, P0341, P0641, or P0651 is not set. |
• | The engine is cranking or running. |
• | The DTC runs continuously when the above conditions are met. |
Important: The ECM detects engine movement by sensing the airflow through the MAF sensor, when airflow is greater than 3 grams per second, or by sensing camshaft position (CMP) sensor pulses.
• | The ECM detects that the starter is commanded on and the engine has been cranking for more than 3 seconds without a CKP sensor pulse. |
• | The ECM detects that the engine is running, but has not received a CKP sensor pulse for 2 of 10 engine cycles. |
• | DTC P0335 is a Type B DTC. |
• | The CMP actuator if equipped is commanded to the parked position. |
• | The ignition system defaults to a limp home mode. The CMP sensor is used to determine engine position. |
DTC P0335 is a Type B DTC.
• | With this DTC set, the engine may crank for an extended period of time during start-up. |
• | This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test. |
Electronic Ignition (EI) System Description
• | Circuit Testing |
• | Wiring Repairs |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
J 35616-A/BT-8637 Connector Test Adapter Kit
• | Close routing of aftermarket electrical equipment. |
• | Close to solenoids, motors, and relays. |
⇒ | If any of these are determined to be a possible source of electrical interference, correct any wire harness routing or component placement conditions. |
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
⇒ | If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the 5-volt reference 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 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | 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. |
⇒ | If the CKP Active counter increments, test or replace the CKP sensor. |
⇒ | If the CKP Active counter does not increment, replace the ECM. |
Important: You must perform the Circuit/System Testing before proceeding with Component Testing.
⇒ | If the sensor is loose, incorrectly installed, or damaged, replace the CKP sensor. |
⇒ | If the parameter does not increment, replace the CKP sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.