07 GS450H help with code and issue

Beretta705 · December 9, 2020

I have a 07 GS450H thats throwing the code P3176

It says it the oil pump temp low and its not allowing the hybrid system to come on it is also followed by C1259 and C1310 codes please help

Britprius · December 9, 2020

Hi Samuel.

The code P3176 is caused by a temperature sensor in the transmission oil pump. This is probably caused by a short or open circuit in the wiring. The pump is an external electrically driven unit on the outside of the transmission on the drivers side.
The other two codes are for regen malfunction of the HV system, and HV system malfunction. These could be related to the oil pump problem.

John.

Beretta705 · December 9, 2020

15 minutes ago, Britprius said:

Hi Samuel.

The code P3176 is caused by a temperature sensor in the transmission oil pump. This is probably caused by a short or open circuit in the wiring. The pump is an external electrically driven unit on the outside of the transmission on the drivers side.
The other two codes are for regen malfunction of the HV system, and HV system malfunction. These could be related to the oil pump problem.

John.

Hello John

Thats what I was thinking and the pump looks corroded externally I don't think it has any issue with the actual control module itself as its receiving 12 volts nominally at the pump itself I figured its an internal issue.

What would be the best way to diagnose the issue before replacing the pump itself?

Also is there anyway to check the transmission fluid level I was wondering if it was also low as a fault

Britprius · December 9, 2020

The way to check the oil level is by removing the fill plug, and filling till oil spills out.

The pump can be removed from under the car. The main problem with the pump is bearing failure, and a new pump is £2500, but the bearings are standard ball races that can be bought for under £5.
The bearing numbers I will Check for you from my files, and let you know later.

John.

Lwerewolf · December 9, 2020

If it looks corroded externally... you don't really want to know how it is on the inside. As John said - the other two are most likely due to the pump.

Anyways - the hardest part about removing the pump is (at least in my opinion) removing the harness - it connects straight to the oil pump controller, which is under the air filter box.

Re: bearings - you might want to read through this: https://club-lexus(blocked word)/forum/viewtopic.php?t=103591&start=0

I changed both bearings and while the shift speed is definitely better, the pump does still make "bearings" noises when sufficiently hot (i.e. in summer weather, after some highway time at 140kph ~= 85mph).

I'd get a second hand pump and refurbish it beforehand if you want to minimize your downtime, for whatever reason. Otherwise, start with the simple stuff.

Info on the transmission (including fill procedure): https://slideplayer.com/slide/14432904/

Beretta705 · December 9, 2020

57 minutes ago, Britprius said:

The way to check the oil level is by removing the fill plug, and filling till oil spills out.

The pump can be removed from under the car. The main problem with the pump is bearing failure, and a new pump is £2500, but the bearings are standard ball races that can be bought for under £5.
The bearing numbers I will Check for you from my files, and let you know later.

John.

Ty sir

Beretta705 · December 9, 2020

1 hour ago, Lwerewolf said:

If it looks corroded externally... you don't really want to know how it is on the inside. As John said - the other two are most likely due to the pump.

Anyways - the hardest part about removing the pump is (at least in my opinion) removing the harness - it connects straight to the oil pump controller, which is under the air filter box.

Re: bearings - you might want to read through this: https://club-lexus(blocked word)/forum/viewtopic.php?t=103591&start=0

I changed both bearings and while the shift speed is definitely better, the pump does still make "bearings" noises when sufficiently hot (i.e. in summer weather, after some highway time at 140kph ~= 85mph).

I'd get a second hand pump and refurbish it beforehand if you want to minimize your downtime, for whatever reason. Otherwise, start with the simple stuff.

Info on the transmission (including fill procedure): https://slideplayer.com/slide/14432904/

Im just hoping that's where the temp sensor is and its not the sensor on the bearing in the manual pump body

Beretta705 · February 24, 2021

I have now replaced both the driver and the pump and changed the fluid. At no luck im still getting the same code and limp mode and don't know what else to do. I'm now only getting P2797 and the trans rattles at startup and shut down Any options or opinions would be appreciated

Mihanicos · February 25, 2021

Always remove the safety plug from the boot and wait 10 minutes before you do any work, give time to the capacitors to discharge. Observe all safety rules in case you accidentally touch any high voltage cables, terminals, pins etc.

P 2797 refers to the auxiliary transmission oil pump driver.

You need to read the freeze frame data where the first thing to check is the voltage value to the driver circuit which should be no less than 10 volts. From the freeze frame data, you should be able to read further codes, ie 865 and 895. If you get 895 together with 865, check the voltage of the oil pump motor driver circuit [ Not less than 10v ] .

P 2797 865 refers to the oil pump control performance. the problem may be with the ecu, the oil pump motor controller, the oil pump motor assembly, or the harness.

First switch the car off and disconnect all connectors from the auxiliary pump. The measured voltage from all terminals on the connectors should be less than 1v.

If you terminals U, V and W are marked on the pump, the measured resistance value between W-U and W-V should less than 1 Ohm.

Then measure the insulation resistance of each pin on the pump with a multimeter and it should be more than 10 K ohms.

Since you have replaced the pump and the diver, by the process of elimination, assuming the new parts are ok, the problem may be with the harness, the connectors, the conditions of their pins and anything that inhibits good conductivity of all common contacts.

Make certain that the ground connection to the gear box and the pump is good and has no contact resistance. It is of paramount importance to have a good ground especially on cars with electronics everywhere. Disconnect both auxiliary Battery terminals and measure the resistance from the Battery ground terminal to the auxiliary oil pump. You should get nearly zero on the multimeter and not more than i Ohm.

The oil level in the transmission should be at the correct level. To check, add oil by removing the hose on the transmission to the oil cooler which is higher than the other hose from the cooler. Normally you add about half a litre more the amount you drained. Circulate the oil with engine running and go through the gears one by one making a stop of about 5 seconds at least at each gear. Do this twice. With the engine running, observe the fluid temperature. Drain between 30C and 40C, preferably 35C. Make certain you have no line pressure code. If you have, add another half litre of oil and repeat the process until the line pressure code is eliminated.

Chris.

Beretta705 · February 25, 2021

4 hours ago, Mihanicos said:

Always remove the safety plug from the boot and wait 10 minutes before you do any work, give time to the capacitors to discharge. Observe all safety rules in case you accidentally touch any high voltage cables, terminals, pins etc.

P 2797 refers to the auxiliary transmission oil pump driver.

You need to read the freeze frame data where the first thing to check is the voltage value to the driver circuit which should be no less than 10 volts. From the freeze frame data, you should be able to read further codes, ie 865 and 895. If you get 895 together with 865, check the voltage of the oil pump motor driver circuit [ Not less than 10v ] .

P 2797 865 refers to the oil pump control performance. the problem may be with the ecu, the oil pump motor controller, the oil pump motor assembly, or the harness.

First switch the car off and disconnect all connectors from the auxiliary pump. The measured voltage from all terminals on the connectors should be less than 1v.

If you terminals U, V and W are marked on the pump, the measured resistance value between W-U and W-V should less than 1 Ohm.

Then measure the insulation resistance of each pin on the pump with a multimeter and it should be more than 10 K ohms.

Since you have replaced the pump and the diver, by the process of elimination, assuming the new parts are ok, the problem may be with the harness, the connectors, the conditions of their pins and anything that inhibits good conductivity of all common contacts.

Make certain that the ground connection to the gear box and the pump is good and has no contact resistance. It is of paramount importance to have a good ground especially on cars with electronics everywhere. Disconnect both auxiliary battery terminals and measure the resistance from the battery ground terminal to the auxiliary oil pump. You should get nearly zero on the multimeter and not more than i Ohm.

The oil level in the transmission should be at the correct level. To check, add oil by removing the hose on the transmission to the oil cooler which is higher than the other hose from the cooler. Normally you add about half a litre more the amount you drained. Circulate the oil with engine running and go through the gears one by one making a stop of about 5 seconds at least at each gear. Do this twice. With the engine running, observe the fluid temperature. Drain between 30C and 40C, preferably 35C. Make certain you have no line pressure code. If you have, add another half litre of oil and repeat the process until the line pressure code is eliminated.

Chris.

Chris.

I appreciate the write up I am a prius mechanic mostly and know them well.

I ran the techstream to turn on the pump through the utilities program but I keep getting a error code same as before with the other pump and driver. Also when I refilled the transmission I used a fluid transfer pump and filled till it came out of the fill plug. So what you are saying is it could be a air pocket in the system, or an electrical fault on the units themselves. I will look to see if there is an error code later........ ty

Mihanicos · February 25, 2021

I quoted the method recommended by Lexus. The line pressure code is stressed all the way in the procedure to check the oil level, addition of transmission fluid and fluid replacement. Fluid circulation is also imperative for all above operations.

My apologies for the somehow detailed write up, I had no idea of your backround. I am an electrical engineer and maintaining and repairing my cars is my hobby.

Please keep us updated and I will help in any way I can to find the fault.

Chris.

Beretta705 · March 1, 2021

On 2/25/2021 at 6:16 AM, Mihanicos said:

I quoted the method recommended by Lexus. The line pressure code is stressed all the way in the procedure to check the oil level, addition of transmission fluid and fluid replacement. Fluid circulation is also imperative for all above operations.

My apologies for the somehow detailed write up, I had no idea of your backround. I am an electrical engineer and maintaining and repairing my cars is my hobby.

Please keep us updated and I will help in any way I can to find the fault.

Chris.

You or anyone else wouldn't happen to have a wiring diagram for this car that will show the grounds would you I'm still having issues tracing it back to figuring out the issue

Cleaned all the connectors I'm getting good voltage. I still can't activate the pump using the Techstream utility without getting a fault P2797 865

ColinBarber · March 1, 2021

I assume you have read through this post:

You can get wiring diagrams from here for around £4 for an hour's access:

https://www.lexus-tech.eu

Mihanicos · March 1, 2021

Attached herewith, please find the relevant circuit diagrams.

Chris.

Beretta705 · March 7, 2021

This may be one of my issues

When I received the used pump the connector plug was broken so we took the plug off the old pump and put the wiring on the used pump back In too the old connector I'm wondering if the wires are in the wrong order

Pictures included in the plug itself which wires are in which spot

Beretta705 · March 7, 2021

Mihanicos · March 8, 2021

Attached here are the pin connections.

Chris

Steven Lockey · March 8, 2021

On 2/25/2021 at 7:13 AM, Mihanicos said:

Always remove the safety plug from the boot and wait 10 minutes before you do any work, give time to the capacitors to discharge. Observe all safety rules in case you accidentally touch any high voltage cables, terminals, pins etc.

Please please please never assume the capacitors are discharged no matter how long you wait.
They can hold a shocking (literally!) amount of power for a long time after the device has been unplugged.

Always assume they are charged till you've tested and made SURE.

Beretta705 · March 8, 2021

5 hours ago, Mihanicos said:

Attached here are the pin connections.

Chris

Ty again Chris for all your help

Is there anyway to determine WVU there's no marking on the wiring or pump

Beretta705 · March 8, 2021

3 hours ago, Steven Lockey said:

Please please please never assume the capacitors are discharged no matter how long you wait.
They can hold a shocking (literally!) amount of power for a long time after the device has been unplugged.

Always assume they are charged till you've tested and made SURE.

I mostly work on Prius but I also rebuild HV traction batteries but I do appreciate your concern so many people don't realize what they are playing with

Mihanicos · March 8, 2021

Regretfully I cannot find anywhere in the circuit diagrams the information you want no matter where I looked and under which heading.

The wiring from the hybrid control ecu to the oil pump motor controller is shown clearly with the connector numbers and the pins. The oil pump motor controller should have the terminals marked on it. From the circuit diagram W,U,V is the three phase supply to the motor.

The other option is to look at another oil pump and verify the connections.

Chris.

Beretta705 · March 8, 2021

2 hours ago, Mihanicos said:

Regretfully I cannot find anywhere in the circuit diagrams the information you want no matter where I looked and under which heading.

The wiring from the hybrid control ecu to the oil pump motor controller is shown clearly with the connector numbers and the pins. The oil pump motor controller should have the terminals marked on it. From the circuit diagram W,U,V is the three phase supply to the motor.

The other option is to look at another oil pump and verify the connections.

Chris.

That's the issue which color wire is VWU

Steven Lockey · March 8, 2021

8 hours ago, Beretta705 said:

I mostly work on Prius but I also rebuild HV traction batteries but I do appreciate your concern so many people don't realize what they are playing with

Wasn't specifically directed at you 🙂

Beretta705 · March 8, 2021

6 hours ago, Mihanicos said:

Regretfully I cannot find anywhere in the circuit diagrams the information you want no matter where I looked and under which heading.

The wiring from the hybrid control ecu to the oil pump motor controller is shown clearly with the connector numbers and the pins. The oil pump motor controller should have the terminals marked on it. From the circuit diagram W,U,V is the three phase supply to the motor.

The other option is to look at another oil pump and verify the connections.

Chris.

That's the issue which color wire is VWU