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2004 Dodge Neon P0340 Code: Won't Start, Cranks But No Fire - Diagnosis & Fixes

Model: 2004 Dodge Neon Fault Code: P0340 Posted: 2015-02-05 10:58

My 2004 Dodge Neon suddenly died while driving on the highway and will not start. The engine cranks normally, all electrical systems function properly, but it fails to fire up. I've received a P0340 diagnostic code indicating an issue with the camshaft position sensor. I have already replaced both the camshaft position sensor and crankshaft position sensor, yet the vehicle still won't start. It turns over when the key is turned, but no combustion occurs. What could be causing this? Any troubleshooting steps or common causes for a 2004 Dodge Neon with P0340 that won't start despite proper electrical function?

Related fault codes
P0340
Comments (8)
Anonymous 2015-02-05 12:14

Note: 'cranking' and 'turning over' are often used interchangeably, but the issue here is clearly not starting or firing. Basic checks to perform: Is there spark? Is fuel pressure present—use a fuel pressure gauge? The P0340 code does not always indicate a faulty sensor; it may point to wiring issues or signal circuit problems. Always verify the actual circuit before replacing components. More details at: http://www.obd-codes.com/p034-0

Anonymous 2015-02-05 15:31

I confirm there is spark and the fuel pump activates when the key is in the 'accessory' position. The vehicle simply won't start. I understand that a P0340 code doesn't always mean the sensor is faulty, but I'm at a loss after replacing several components under the hood. I've done extensive tuning and maintenance at home, yet no success in getting it to fire up.

Anonymous 2015-02-05 16:17

Without a reliable OBD2 scanner, start with basic diagnostics: Are there sparks at all four spark plugs? What do the plugs look like—wet, dry, black, or tan? The fuel pump kicks on in accessory mode. Try spraying carburetor or brake cleaner into the throttle body while someone attempts to crank it—does the engine respond (firing)? Also, check for 12V at the injector connectors (typically dark green/orange wire) at any injector.

Anonymous 2015-02-05 18:22

The spark plugs and plug wires are brand new. Before replacement, only the third and fourth plugs showed brown deposits. I will try the throttle body spray test tomorrow when it's light out and warmer. I’ve confirmed that there is 12V at each injector connector.

Anonymous 2015-02-06 10:07

New spark plugs do not guarantee proper ignition—spark must be delivered to the correct cylinder in the right sequence. Try the throttle body spray test and report results. This can help determine if the engine is actually firing or just cranking.

Anonymous 2015-02-08 21:52

The check engine light is on, and a P0300 code has appeared—what does this mean? How should I diagnose and fix it?

Anonymous 2015-02-08 21:55

Additional codes PO154 and PO151 have surfaced—what do these mean and how can they be addressed?

Anonymous 2015-02-08 23:29

bcombee wrote: The codes PO154 and PO151 came up—what are they? Please start a new topic with more detailed information about these specific codes.