Diagnostic Trouble Code
P2318
Ignition Coil G Primary Control Circuit Low
Technical Description P2318
Ignition Coil G Primary Control Circuit Low
Severity Level P2318
When a P2318 is stored, the cause should be diagnosed as soon as possible. Symptoms which likely accompany these codes will usually demand immediate attention.
Symptoms P2318
1
Engine misfire
2
Diminished engine performance
3
Reduced fuel efficiency
4
Other related codes
5
Fuel injector operation for the affected cylinder may be disabled by the PCM
Possible Causes P2318
1
Bad relay or blown fuse (fusible link)
2
PCM failure
3
Open or shorted wiring or wiring connectors (wildlife damage)
4
Defective ignition coil
5
Faulty camshaft or crankshaft sensor or wiring
Solutions & Repair Steps P2318
You will need a diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of reliable vehicle information in order to accurately diagnose a code P2318.
You may save yourself time and trouble by searching for technical service bulletins (TSB) that replicate the code stored, vehicle (year, make, model, and engine), and symptoms exhibited. This information may be found in your vehicle information source. If you find the right TSB, it could yield a speedy solution to your diagnosis.
After you connect the scanner to the vehicle diagnostic port and retrieve all stored codes and pertinent freeze frame data, write the information down (in case the code proves to be an intermittent one). After that, clear the codes and test drive the vehicle until one of two things happens; the code is restored or the PCM enters readiness mode.
The code may be more difficult to diagnose if the PCM enters readiness mode at this point, because the code is intermittent. The condition which caused the P2318 to be stored may need to worsen before an accurate diagnosis can be made. If the code is restored, continue with the diagnosis.
You may obtain connector face views, connector pinout charts, component locator charts, wiring diagrams, and diagnostic flow charts (pertaining to the code and vehicle in question) using your source of vehicle information.
Perform a visual inspection of related wiring and connectors. Repair or replace wiring that has been cut, burned, or damaged. Wiring on top of the engine is often damaged by wildlife attempting to stay warm in cold climates.
Use the DVOM to test voltage and ground circuits at the ignition coil in question. If no voltage is detected, check the system relay and related fuses. Replace defective relays and/or blown (or otherwise defective) fuses as required.
If voltage and ground are detected at the coil, test the corresponding ground circuit at the PCM connector with the engine running. If ground pulse is detected there, suspect an open circuit between the coil in question and the PCM. If no ground pulse is discovered there, suspect a defective PCM, or a programming error.
You may save yourself time and trouble by searching for technical service bulletins (TSB) that replicate the code stored, vehicle (year, make, model, and engine), and symptoms exhibited. This information may be found in your vehicle information source. If you find the right TSB, it could yield a speedy solution to your diagnosis.
After you connect the scanner to the vehicle diagnostic port and retrieve all stored codes and pertinent freeze frame data, write the information down (in case the code proves to be an intermittent one). After that, clear the codes and test drive the vehicle until one of two things happens; the code is restored or the PCM enters readiness mode.
The code may be more difficult to diagnose if the PCM enters readiness mode at this point, because the code is intermittent. The condition which caused the P2318 to be stored may need to worsen before an accurate diagnosis can be made. If the code is restored, continue with the diagnosis.
You may obtain connector face views, connector pinout charts, component locator charts, wiring diagrams, and diagnostic flow charts (pertaining to the code and vehicle in question) using your source of vehicle information.
Perform a visual inspection of related wiring and connectors. Repair or replace wiring that has been cut, burned, or damaged. Wiring on top of the engine is often damaged by wildlife attempting to stay warm in cold climates.
Use the DVOM to test voltage and ground circuits at the ignition coil in question. If no voltage is detected, check the system relay and related fuses. Replace defective relays and/or blown (or otherwise defective) fuses as required.
If voltage and ground are detected at the coil, test the corresponding ground circuit at the PCM connector with the engine running. If ground pulse is detected there, suspect an open circuit between the coil in question and the PCM. If no ground pulse is discovered there, suspect a defective PCM, or a programming error.