• | 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 | P0340 | P0340 | -- | -- |
CMP Sensor Signal Circuit | P0340 | P0340 | P0340 | P0341 |
Low Reference Circuit | -- | P0340 | -- | -- |
Camshaft Position Signal | P0340 | P0340 | P0340 | P0341 |
The camshaft position (CMP) sensor is a 1X sensor. The CMP sensor provides one digital ON/OFF signal to the ignition control (IC) module per revolution of the camshaft. The CMP sensor is connected directly to the IC module and sends the CMP sensor pulses to the powertrain control module (PCM) on the camshaft position signal. This information is used by the PCM to determine the position of the valve train relative to the crankshaft position (CKP). By monitoring the CMP and CKP signals, the PCM can accurately time the operation of the fuel injectors. The PCM monitors the CMP sensor for errors. The CMP sensor wiring includes the following circuits:
• | The CMP sensor signal circuit |
• | A shared 12-volt reference circuit |
• | A shared low reference circuit |
• | A camshaft position signal circuit |
• | 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 6 low engine speed signals and 0 camshaft position signal. |
• | The above condition is met for more than 8 seconds. |
DTC P0340 is a Type B DTC.
DTC P0340 is a Type B DTC.
Electronic Ignition (EI) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
⇒ | If less than the specified range, test the IC module ignition voltage circuit for an open/high resistance or short to ground. |
⇒ | If greater than the specified value, test the low reference circuit for an open/high resistance. |
⇒ | If less than the specified range, test the 12-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the IC module. |
⇒ | 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 IC module. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the IC module. |
⇒ | If the CMP Sensor RPM parameter increments, replace the CMP sensor. |
⇒ | If the CMP Sensor RPM parameter increments, replace the IC module. |
⇒ | If the CMP Sensor RPM parameter does not increment, test the camshaft position signal circuit for an open/high resistance, short to ground, or a short to voltage. If all circuits test OK, replace the PCM. |
⇒ | If the Duty Cycle does not increment, replace the CMP sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for IC module, and PCM replacement, setup, and programming |