← Back to list

1999 Toyota Camry P0340 Code: Can the PCM Be Diagnosed Without Replacement?

Model: 99 Toyota Camry Fault Code: P0340 Posted: 2007-06-19 08:01

Hello, My sister-in-law owns a 1999 Toyota Camry with a 4-cylinder engine. Recently, I detected a P0340 trouble code using my OBD2 scan tool. The vehicle exhibits classic symptoms of hard starting, misfiring, and loss of power—typically requiring about 20 minutes to start successfully. During operation, only cylinders 3 and 4 are firing consistently. I've already performed ohm and voltage tests on all relevant sensors and wiring, and the results appear normal. My questions are: 1. What are the expected voltage levels and signal patterns from the camshaft position sensor? 2. Is there a way to diagnose or test the Powertrain Control Module (PCM) without replacing it—especially since replacement can be costly? 3. Given that the camshaft position sensor is a known common issue on this model, is there an easy method to verify if the sensor itself is faulty? 4. Could I have missed another underlying cause? Are there any other potential issues to consider? Any insights or troubleshooting steps would be greatly appreciated.

Related fault codes
P0340
Comments (3)
Anonymous 2007-06-19 09:19

It's possible that the timing belt has slipped—this is a common issue on older Toyota Camrys and can cause misfiring and erratic engine behavior. A visual inspection of the timing belt and related components may reveal signs of slippage or wear.

Anonymous 2007-06-19 10:27

Before replacing any parts, confirm whether the cylinders that aren't firing are experiencing a lack of fuel, spark, or both. This helps isolate whether the issue lies with ignition, fuel delivery, or sensor input to the PCM.

Anonymous 2007-06-19 10:51

While my experience with Toyota vehicles isn't always positive, most 4-cylinder models will only fire on two cylinders when the timing belt has slipped. If the vehicle has high mileage and is due for a belt replacement anyway, it's advisable to inspect the timing belt before investing in expensive repairs like a PCM or camshaft sensor replacement.