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Category: Lexus
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I have a Lexus 2002 RX300. A few days ago my car began to

Customer Question

Hi Jason, I have a Lexus 2002 RX300. A few days ago my car began to accelerate unexpectedly and gears wouldn't change. I had it diagnosed and received error codes P765 and P770 and P1135. Also note that I started it yesterday and drove it down street with no problems, only minor squeaking sound coming under hood. What is going on? Please advise as I haven't had any major issues with this SUV and am very concerned. Thank you
Submitted: 2 years ago.
Category: Lexus
Expert:  scionking replied 2 years ago.

Any recent work to this like valve covers, or spark plugs?

I'm questioning the ground on the back of the intake.

Customer: replied 2 years ago.
No recent work performed.
Expert:  scionking replied 2 years ago.

I would still check the ground on the back side of the intake manifold, this is known to give oxygen sensor and transmission sensor codes.

Customer: replied 2 years ago.
Please elaborate as I'm not following you. Do I need to have it diagnosed again or do I need to physically check something?
Expert:  scionking replied 2 years ago.

Yes sorry I had to step away from the computer for a bit, there is a ground wire that needs to be check to confirm whether is connected well, it is in the back center of intake manifold, I can send you a picture of it?

Expert:  scionking replied 2 years ago.

Ground location circled in red in first pic, arrow 1 points to the actually ground wire removed in picture.

Ground location shown in second picture( there is also circled in red one on the side of intake, wouldn't hurt to check that to)

Expert:  scionking replied 2 years ago.

They uploaded in a different order 1 is 2 and 2 is 1.

I've witnessed these grounds installed by a thread or two at time of repair then months/miles later the bolt backs out and losses connection when it falls out. This is commonly removed when doing spark plugs of valve cover gaskets. I would first eliminate this as a possibility before progressing any further in finding the cause of the check engine light.