• | 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 |
---|---|---|---|---|
12-Volt Reference Circuit | P0385¹ | P0385¹ | -- | -- |
CKP Sensor Signal Circuit | P0385¹ | P0385¹ | P0385¹ | P0386 |
Low Reference Circuit | -- | P0385¹ | -- | -- |
Medium Resolution Engine Speed Signal | P0385¹ | P0385¹ | P0385¹ | P0386 |
¹ Engine Cranks but does not run |
The crankshaft position (CKP) sensor contains 2 hall-effect switches in one housing. This sensor configuration produces 2 separate CKP sensor pulses. These pulses occur when 2 interrupter rings, mounted to the crankshaft balancer, the outer one containing 18 evenly spaced windows and blades, the inner one containing 3 unevenly spaced windows and blades, pass by the sensors. The 18X sensor produces 18 pulses per engine revolution. The 3X sync sensor produces 3 pulses per engine revolution, each pulse representing a pair of companion cylinders. Both sensors are connected directly to the ignition control (IC) module. The sensor wiring includes the following circuits:
• | The CKP sensor 1 signal circuit |
• | The CKP sensor 2 signal circuit |
• | A shared 12-volt reference circuit |
• | A shared low reference circuit |
• | A low resolution engine speed signal circuit |
The IC Module uses the sensors to determine the engine position and speed. A signal converter within the IC Module, using the 18X CKP sensor 1, produces a digital 18X output signal to the powertrain control module (PCM) on the medium resolution engine speed signal circuit. The PCM monitors the low resolution engine speed signal circuit for errors.
• | The engine is cranking or running for more than 3 seconds. |
• | The DTC runs continuously when the above condition is met. |
Important: The PCM detects engine movement by sensing the airflow through the mass air flow (MAF) sensor is more than 3 g/s, or by sensing CMP sensor pulses.
• | The PCM detects 36 medium resolution engine speed signals for every 2 engine revolutions while receiving, 1 camshaft position signal and a number other than 0 or 6 low resolution engine speed signals. |
• | The above conditions are met for more than 8 seconds. |
DTC P0386 is a Type B DTC.
DTC P0386 is a Type B DTC.
Electronic Ignition (EI) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | Close routing of secondary ignition wires |
• | Close routing of aftermarket electrical equipment |
• | Close to solenoids, motors, and relays |
⇒ | Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference. |
⇒ | If greater than the specified value, test the low resolution engine speed signal circuit for an open/high resistance. |
⇒ | If the sensor is loose, inspect the sensor and the O-ring for damage. Replace as necessary. |
• | Engine oil for debris and contamination |
• | Crankshaft reluctor wheel for damage |
• | The timing chain, tensioner, and sprockets for wear or damage |
⇒ | If debris is found in the engine oil, inspect the internal engine components to determine the cause. Repair or replace any worn or damaged components. |
⇒ | If the Duty Cycle does not increment, replace the CKP sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for IC Module, and PCM replacement, setup, and programming |