2007 Lexus Rx 350 check engine light tampered with?

[RachWeber45]

I just recently bought a 2007 Lexus Rx 350 drives great. Only code that came up before purchase was a traction control (VSC) which is not that big of a deal. I take it to get smogged and it failed. The report says check engine light has been tampered with because it doesn’t come on at all. I had a mechanic take a look and he pulled out the cluster and it didn’t look like anything was amiss. There is no actual bulb it’s just a circuit board. All the wires are intact. He was baffled as to how someone could have made it to where only the check engine light doesn’t come on. Every other light works. Can anyone give me any input? TIA.

[zieke]

Rachel,  I'm guessing there is a loose solder joint somewhere either in the cluster or at the main computer if the light doesn't come on when you turn on the ign. before you start the car. If the smog people could check for codes I would think that result should be good enough to pass your RX.  The traction control is probably just a sensor if it stays on. You can also have auto zone or etc. reset the codes for free. Good luck.

[RX400h]

On 3/6/2024 at 8:53 AM, RachWeber45 said:

I just recently bought a 2007 Lexus Rx 350 drives great. Only code that came up before purchase was a traction control (VSC) which is not that big of a deal. I take it to get smogged and it failed. The report says check engine light has been tampered with because it doesn’t come on at all. I had a mechanic take a look and he pulled out the cluster and it didn’t look like anything was amiss. There is no actual bulb it’s just a circuit board. All the wires are intact. He was baffled as to how someone could have made it to where only the check engine light doesn’t come on. Every other light works. Can anyone give me any input? TIA.

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It’s interesting that your 2007 Lexus RX 350 has a check engine light issue. While I can’t diagnose the specific problem, I can offer some general insights:

1. Check Engine Light (CEL) Tampering: If the smog report indicates that the check engine light has been tampered with, it’s essential to address this issue. Tampering with the CEL can lead to a failed smog test.

2. No Bulb, Just a Circuit Board: The absence of an actual bulb for the check engine light suggests an electrical issue. The check engine light typically illuminates when the car’s onboard computer detects a fault in the engine or emissions system. Since the wires appear intact, it’s puzzling why only the check engine light is affected.

3. Possible Causes:

   • Faulty Bulb or LED: Even though there’s no physical bulb, there might be an LED or other light source on the circuit board. It could be malfunctioning.
   • Faulty Sensor or Wiring: The check engine light relies on various sensors and wiring. A faulty sensor (such as an oxygen sensor) or damaged wiring could prevent the light from illuminating.
   • ECU (Engine Control Unit) Issue: The ECU manages the check engine light. If it’s not sending the signal to illuminate the light, there could be an issue with the ECU itself.
   • Previous Owner Modifications: Sometimes previous owners modify wiring or disable lights intentionally. It’s possible someone altered the system to avoid addressing an underlying issue.

4. Next Steps:

   • Professional Diagnosis: Consider taking your Lexus to a certified mechanic or dealership. They can perform a thorough diagnostic scan to identify any stored trouble codes and assess the system.
   • Resetting the Light: If the issue is resolved, the mechanic can reset the check engine light. However, ensure that the underlying problem is genuinely fixed.
   • Legal Implications: Tampering with emissions-related systems can have legal consequences. Ensure the issue is resolved correctly to comply with regulations.

Remember that tampering with emissions systems can impact both performance and environmental compliance. Seek professional assistance to diagnose and rectify the issue.