The 2004 Toyota Camry, known for its reliability, can occasionally experience no-start issues. This article details a challenging case study of a 2004 Camry with intermittent no-start problems, highlighting the diagnostic process and potential solutions.
A Persistent Problem: Intermittent No-Start
A 2004 Toyota Camry with a 2.4L DOHC engine and approximately 120,000 miles presented with an intermittent no-start condition. The vehicle would occasionally cut out while driving and sometimes restart. Initially, aftermarket camshaft and crankshaft position sensors were replaced, providing temporary relief. However, the issue returned, eventually leading to a complete no-start situation.
Initial Diagnosis and Attempts
The vehicle exhibited injector pulse but no spark. While an ohmmeter indicated functionality in the crankshaft position sensor, a known issue with aftermarket sensors prompted the installation of an OEM sensor. This temporarily resolved the problem, but the no-start condition reoccurred after a short period.
Further investigation included sending the Powertrain Control Module (PCM) for testing, which revealed no faults. Harness and connector inspections showed no damage. A PCM from a comparable Camry was installed, resulting in normal operation for three days before the problem resurfaced.
Further Troubleshooting Steps
Extensive testing revealed that maintaining power to the 15-amp ignition fuse allowed the engine to run. Voltage fluctuations were observed on both ignition fuses, but this behavior was also present in a known good Camry. Relays were inspected and reinstalled. Interestingly, after connecting a battery charger and holding the ignition key in the start position for an extended period, the engine started and ran flawlessly for several hours before the no-start issue returned.
Seeking Solutions: Possible Causes
Despite exhaustive efforts, the root cause remained elusive. All components tested within specifications when the engine was running. There were no Diagnostic Trouble Codes (DTCs) stored. Fuel pressure was normal, and no evidence of fuel system related shutdowns was found. Attempts to induce a limp mode were unsuccessful. Even with a known good PCM, the problem persisted. Potential causes for this type of intermittent no-start condition in a 2004 Toyota Camry could include:
- Wiring Harness Issues: Despite visual inspection, intermittent wiring harness faults can be difficult to detect and may require specialized testing equipment.
- Faulty Ignition Switch: A malfunctioning ignition switch may not consistently provide the necessary power to the ignition system.
- Grounding Problems: Poor grounding can disrupt electrical signals and contribute to intermittent starting issues.
- Intermittent Relay Failure: While relays were inspected, an intermittent failure could be occurring under specific conditions.
Conclusion
This case highlights the complexities of diagnosing intermittent no-start problems in a 2004 Toyota Camry. While the initial focus was on sensors and the PCM, the problem likely lies within a less obvious electrical fault. Further diagnostic steps, including a thorough inspection of the wiring harness, ignition switch, and grounding points, are recommended. Specialized electrical testing equipment might be necessary to pinpoint the intermittent fault.
