Hi everyone,

Recently picked up a 2006 GS300 with 130,000 Km's on the clock as as my daily run around. I thought it would help reduce the number of km's I put on the LS600hL . Unfortunately having a few issues with the transmission... it isn't going into 5th or 6th gear. I have read that this could be to do with the Engine Management Computer or solenoids. Also not getting the shifter position showing up in the dash cluster. When I scan the vehicle I get the following errors on my scan tool:

-P0705 Transmission Range Sensor Circuit
-P3000 Battery Control System
-P0003 Fuel Volume Regulator Control Circuit Low

Any insight or suggestions would be greatly appreciated

 

I know the older GS have trans computer issues, there is a service that can rebuild them. Others may have more info.

 

I think you may have a battery or alternator issue, I would get both tested out. If you have a low voltage, say alternator is bad it would kill other modules in the car. So I would start with the obvious, check the battery terminals make sure there clean and nice and tight. Then I would drive to an auto parts store and have them test your battery and alternator.

If the cars been sitting for awhile, unused the 3GS like to pop up battery codes.

 

Transmission issues are common for the 3rd Gen GS, the most likely problem is the ECT module that can't be purchased new anymore and any 2nd hand options WILL have the same problem; there are places that can repair them. 80% of the time this is the cause of GS300 transmission problems.

Given you also don't have the shift light I would guess it's the ECT module causing the concern, though the not ****ing into 5/6th can also hint toward the Line Pressure solenoid and the Lock-up solenoid. People mistakingly replace the 2 shift solenoids hoping it will fix the problem...it won't. Even if you repair the module it's a good practice to replace the transmission filter and flush the transmission as it's marketed as 'Lifetime Fluid (WS Fluid in Toyota world)'. People assume it means lifetime of the vehicle and never replace it, the truth is its lifetime of the warranty and needs to be done at 150,000kms.

Your P3000 and P003 codes could be from a failing alternator. Generally 'low circuit codes appear in lower than ideal voltage situations or battery failure/ replacements, you cannot replace this with a non-genuine option. Well, you can replace it but it will fail prematurely. It has to be a genuine item for the 2006 model.

 

Hi mate,

thanks for the detailed reply, appreciate your response. I need to send the ECT module away for repair, I’ve found a few companies that do this here in Aus and I guess then go from there. If issues arn’t resolved then move on to solenoids?

Alternator is definitely dead… what are your thoughts on reconditioning the failed genuine one that is currently in the vehicle. My only concern about a new genuine one is the cost, it’s over 2 grand for one

 

Not a problem mate, where in Aus are you sending it to? The standard price here in QLD is around 600 bucks, I would be very surprised if the module repair didn't fix it completely. The solenoids are points of failure but not a common one.

Recon should be fine* it's just the non-OEM ones don't have the same resistance across something within the alternator itself, I can't remember exactly what part but I know they won't work for long and it can cause issues downstream.

*I've never dealt with a recon one, I worked for Lexus as a technician and only ever replaced failed units with OEM replacements. We did try the aftermarket option for a few cars over the years and every one of them came back at some point with the same issues. Some in a month, some in 6, some lasted a year but they all died the same death in the end.