Major Error in Lexus Repair Manual
artbuc
08-08-2007, 07:39 AM
RE: 1999 Lexus Repair Manual RM626U2 for RX300
Electrical troubleshooting checks given in Volume 2, pages SF-42 and SF-46 for IACV are WRONG! IACV's in this vehicle are magnetic induction type and resistance measurements across the open and close circuits are meaningless. Also, you can't manually open/close valve by applying 12VDC across circuits. The info contained in this Lexus manual applys to rotary solenoid type valves like the one in my 99 Avalon.
After getting low/rough cold start idle at 78k miles, I removed the IACV to give it a good cleaning. Thought I may as well do the electrical checks per my Repair Manual even though I know electrical failures in an IACV are very rare. Based on bogus manual info, I concluded IACV was bad and purchased a new one from Lexus. It checked-out exactly like my old one!. Called Lexus and couldn't find anyone to give me an explanation. After some research I connected with an engineer from Wells Engine Management Systems who makes an aftermarket IACV for the RX. I think they may also be an OEM supplier to Toyota. The Wells engineer explained why the Repair Manual electrical checks would not work on this IACV.
I called Lexus Materials Distribution and they confirmed that the Repair Manual they are selling today is exactly the same one I purchased in 1999. It has not been been corrected to deal with this error.
I have asked Lexus to reimburse me for the $224 I spent on a new IACV. They said they would consider my request and get back to me in a couple days.
Electrical troubleshooting checks given in Volume 2, pages SF-42 and SF-46 for IACV are WRONG! IACV's in this vehicle are magnetic induction type and resistance measurements across the open and close circuits are meaningless. Also, you can't manually open/close valve by applying 12VDC across circuits. The info contained in this Lexus manual applys to rotary solenoid type valves like the one in my 99 Avalon.
After getting low/rough cold start idle at 78k miles, I removed the IACV to give it a good cleaning. Thought I may as well do the electrical checks per my Repair Manual even though I know electrical failures in an IACV are very rare. Based on bogus manual info, I concluded IACV was bad and purchased a new one from Lexus. It checked-out exactly like my old one!. Called Lexus and couldn't find anyone to give me an explanation. After some research I connected with an engineer from Wells Engine Management Systems who makes an aftermarket IACV for the RX. I think they may also be an OEM supplier to Toyota. The Wells engineer explained why the Repair Manual electrical checks would not work on this IACV.
I called Lexus Materials Distribution and they confirmed that the Repair Manual they are selling today is exactly the same one I purchased in 1999. It has not been been corrected to deal with this error.
I have asked Lexus to reimburse me for the $224 I spent on a new IACV. They said they would consider my request and get back to me in a couple days.
Automotive Network, Inc., Copyright ©2025