Owner's Problem Description
The owner of a 2007 Lexus RX350 is inquiring about the location of ignition coil B, specifically for cylinder #2, after receiving a check engine light with the P0352 code. They had previously replaced ignition coil #6 and were charged more for labor due to its difficult access. They want to confirm if ignition coil #2 is accessible and whether they might incur additional labor costs for this repair.
Professional Technical Analysis
The 2007 Lexus RX350 is equipped with a 3.5L V6 engine and features individual ignition coils for each cylinder, specifically designed for efficient ignition timing and performance. The P0352 code indicates a malfunction in ignition coil #2, which requires prompt attention to avoid potential engine misfires and reduced performance. Based on the vehicle's design, the ignition coils are mounted on the engine's valve covers, with cylinders #2, #4, and #6 located on the rear side, while cylinders #1, #3, and #5 are positioned at the front. The ignition coil for cylinder #2 is located on the passenger side of the engine bay, making it more accessible compared to the rear coils, which often require additional labor due to their positioning. In this case, previous experiences with labor costs for accessing ignition coils have led to concerns about being overcharged. Understanding the layout of the engine's ignition system is crucial for effective diagnostics and repairs, as proper access can significantly influence repair time and cost. Overall, the vehicle is in good condition, but the check engine light suggests a need for immediate investigation to ensure optimal engine performance and reliability.
Possible Causes
Most common causes (ordered by frequency):
- Ignition Coil #2 Failure: The P0352 code indicates a malfunction in the ignition coil for cylinder #2, which may be due to electrical issues such as short circuits or open circuits within the coil itself. Testing the resistance of the coil should yield a value between 0.5-1.5 ohms when checked for primary resistance. If the coil is found to be defective, replacing it with an OEM part (P/N 90919-02200) is recommended. - Check engine light illuminated, resistance testing shows out of specification values, potential visible damage to the ignition coil.
- Wiring or Connector Issues: Faulty wiring or corroded connectors leading to poor connection can also result in the P0352 code. Visual inspection of the wiring harness and connectors related to the ignition coil is necessary. Resistance should be measured for continuity, and any corroded or damaged connectors should be replaced. - Corrosion observed at connectors, intermittent connection issues during testing, voltage drop noted in wiring.
- PCM (Powertrain Control Module) Issues: In some cases, malfunction of the PCM can lead to erroneous codes like P0352. If the wiring and the ignition coil are both verified to be functional, testing the PCM for proper operation may be necessary. This can involve using a scan tool to check for additional fault codes and verifying PCM output signals. - No additional codes found, PCM output signals not showing expected values during testing.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - OBD-II Code Retrieval: Begin by using a professional OBD-II scanner or the GeekOBD APP to retrieve the P0352 code. Ensure to check the freeze frame data for additional context on when the fault occurred, such as engine temperature and RPM. This can help in identifying the conditions that triggered the fault.
- STEP 2 - Visual Inspection: Conduct a thorough visual inspection of the ignition coil #2 and its wiring. Look for signs of wear, damage, or corrosion on the coil and connectors. Any visible issues should be documented and addressed before proceeding with electrical tests.
- STEP 3 - Resistance Testing: Measure the resistance of ignition coil #2 using a multimeter. The primary resistance should fall within 0.5-1.5 ohms. If the resistance is out of specification, replace the coil with an OEM part and retest the system.
- STEP 4 - Conduct Continuity Tests: Use a multimeter to check the continuity of the wiring harness and connectors related to ignition coil #2. Ensure there are no breaks or shorts in the wiring that could affect the coil's operation.
