Wire Harness Problem

[mj mike]

I'm new to LOC...Have a GX '03 with no major problems until last week. My wife turned off car, removed key and the radio, and panel lights stayed on, along with A/C. Tried resetting, took out fuses, etc, but no luck. Dealer has spent many hours trying to identify problem (ruled out ignition switch). They say the factory has NEVER seen this problem before! Their recommendation is to replace the entire wire harness. Estimate would be aprrox. 6K to replace. Anyone ever hear of this problem before?

[SailorDanH]

Replacing the entire wiring harness is what I'd do if I was the shop manager, had no brains and no scruples, and was short on meeting my revenue targets for the month.

I recommend going to a non-Lexus service facility. I have first hand knowledge of situations like yours in which the Lexus team took the easy way out even though the cost was much greater (to the customer).

[1990LS400]

So the dealer would rather take a shotgun approach instead of diagnosing the problem? Ridiculous. A proficient automotive electrician should be able to quickly diagnose the problem using the electrical diagrams for your car, the diagnostic instructions in the shop manuals, and by verifying voltage, continuity and resistance starting at the audio and A/C systems and working backwards along the harness.

The problem could be caused by something as as simple as corrosion in a fuse block. Do you know the car's history ... e.g. it isn't one of the "Katrina cars" that has "flooded" the market?

[mj mike]

Replacing the entire wiring harness is what I'd do if I was the shop manager, had no brains and no scruples, and was short on meeting my revenue targets for the month.

I recommend going to a non-Lexus service facility. I have first hand knowledge of situations like yours in which the Lexus team took the easy way out even though the cost was much greater (to the customer).

[mj mike]

Replacing the entire wiring harness is what I'd do if I was the shop manager, had no brains and no scruples, and was short on meeting my revenue targets for the month.

I recommend going to a non-Lexus service facility. I have first hand knowledge of situations like yours in which the Lexus team took the easy way out even though the cost was much greater (to the customer).

Thanks. I was hoping the dealer would've gotten a top level tech involved. Can't believe I'm the first one with this problem.

[mj mike]

So the dealer would rather take a shotgun approach instead of diagnosing the problem? Ridiculous. A proficient automotive electrician should be able to quickly diagnose the problem using the electrical diagrams for your car, the diagnostic instructions in the shop manuals, and by verifying voltage, continuity and resistance starting at the audio and A/C systems and working backwards along the harness.

The problem could be caused by something as as simple as corrosion in a fuse block. Do you know the car's history ... e.g. it isn't one of the "Katrina cars" that has "flooded" the market?

Thanks for the info. No, it's not a Katrina model. Amazing that we have it for 6 years and 105K miles and this happens. Want to trade in, but most likely need to get this fixed first.

[mann777]

This is definetely not a harness issue here, as to what you have quoted, It has to between the Ignition box and the ECU, there is error code getting generated which are retaining few functions. Just ask the dealer prior to changing the harness to do a Flash Re-programming of the ECU. My Gut feeling is the ECU is slowly dying. I had the similar issue on the LS400, This happened with the Ignition and headlamp and the Interior light being on after the keys removed. I finally had to disconnect the battery. Manage to get a ECU from the yard. It has been 4 years and perfectly working.

[mj mike]

This is definetely not a harness issue here, as to what you have quoted, It has to between the Ignition box and the ECU, there is error code getting generated which are retaining few functions. Just ask the dealer prior to changing the harness to do a Flash Re-programming of the ECU. My Gut feeling is the ECU is slowly dying. I had the similar issue on the LS400, This happened with the Ignition and headlamp and the Interior light being on after the keys removed. I finally had to disconnect the battery. Manage to get a ECU from the yard. It has been 4 years and perfectly working.

Thanks for the input. Will have the dealer do the flash reprogram of the ECU. I also have the LS430. Hopefully, this won't be an issue with that car.