R33 GTST (not GTR) Wiring Schematics Anyone? (Active LSD)

[jacobzking]

Anyone have R33 GTST schematics they can share.  I've had a few guys share schematics for the GTR, but have not come across the GTST schematics.  STILL trying to get my Active LSD to work. (93 R33 GTST).

Specifically looking for the 6 pin connector Active LSD "Gravity Sensor" schematics (GTST only has the 6 pin connector, unlike the GTR that has a 6 AND a 4 pin)

And then the ABS/A-LSD CU schematics.

 

These are my error codes.  And I've tried 2 other gravity units, all with the same results:

62 FR and RR G sensor 2 and circuit

65 G- sensor 2 power supply and circuit

66 Side G sensor and circuit

[joshuaho96]

2 hours ago, jacobzking said:

Anyone have R33 GTST schematics they can share.  I've had a few guys share schematics for the GTR, but have not come across the GTST schematics.  STILL trying to get my Active LSD to work. (93 R33 GTST).

Specifically looking for the 6 pin connector Active LSD "Gravity Sensor" schematics (GTST only has the 6 pin connector, unlike the GTR that has a 6 AND a 4 pin)

And then the ABS/A-LSD CU schematics.

 

These are my error codes.  And I've tried 2 other gravity units, all with the same results:

62 FR and RR G sensor 2 and circuit

65 G- sensor 2 power supply and circuit

66 Side G sensor and circuit

You need to do the following diagnostic flows to narrow down the issue:

 

If you need a wiring diagram you can find it here under A-LSD/ABS: http://yariksteel.ru/manual/R33/Skyline_R33_elektroprovodka.pdf

Edited August 22, 2023 by joshuaho96

[jacobzking]

On 8/21/2023 at 11:46 PM, joshuaho96 said:

You need to do the following diagnostic flows to narrow down the issue:

 

If you need a wiring diagram you can find it here under A-LSD/ABS: http://yariksteel.ru/manual/R33/Skyline_R33_elektroprovodka.pdf

 

Is there a flow chart like this for the GTST that you know of?  Since the GTST only has one plug on the sensor, and is missing some of those pinouts on the CU.

I ran through the flow chart and got the appropriate 8V at the 2 pins on the G sensor connector (pins 27-29).  At that point, according to Nissan, needs a new G sensor.  Ive tried 3 different sensors, but what are the chances all 3 are bad?  I've also tried checking voltage out of the sensor (pins 41 and 43) and I'm getting much less than 2.5V.

PS: I get codes 62 (FR and RR G sensor 2 and circuit).  65 G Sensor 2 Power Supply and circuit.  66 Side G sensor and Circuit.

 

[joshuaho96]

On 9/17/2023 at 11:12 AM, jacobzking said:

 

Is there a flow chart like this for the GTST that you know of?  Since the GTST only has one plug on the sensor, and is missing some of those pinouts on the CU.

I ran through the flow chart and got the appropriate 8V at the 2 pins on the G sensor connector (pins 27-29).  At that point, according to Nissan, needs a new G sensor.  Ive tried 3 different sensors, but what are the chances all 3 are bad?  I've also tried checking voltage out of the sensor (pins 41 and 43) and I'm getting much less than 2.5V.

PS: I get codes 62 (FR and RR G sensor 2 and circuit).  65 G Sensor 2 Power Supply and circuit.  66 Side G sensor and Circuit.

 

I'm not really sure what you're saying when you said you ran through the flow chart. Pin 92 appears to be a ground. I would verify that has a good connection. Pin 27 and 29 relative to ground should be 8V as you said. For the GTST single plug if pin 27 and 29 are +8V then 26 and 28 should be the signal output. Verify that the supply voltage stays at roughly 8V with the sensor connected. Then verify that the voltage you get at pin 27 and pin 29 is also what you expect. On a flat table not moving it should be 2.5V. Then check against pin 40, 41, 42, and 43 on your A-LSD control unit. On the g-sensor those are equivalent to pin 27, 26, 28, and 29 respectively if I'm reading the wiring diagram correctly that I linked in my previous post. Should be page 28 of 31 where the A-LSD/ABS control unit pinout is shown. If you can't find it see below:

If you have verified the signals are making it through the harness ok with everything connected up then yes, if you aren't getting about 2.5V from the signal pins relative to body earth you have a dead sensor. It's also not that unlikely because it is basically a glorified pendulum with some springs in there attached to a potentiometer to measure position. If someone dropped the sensor at any point from when it was built to any number of shipping depots and junkyards between the point of manufacture and you over the past 3 decades it's possible that the potentiometer breaks or the springs are permanently deformed and it'll read weird values just sitting there. The red shock sensor not reading excessive force is not proof that the sensor works. Just plain wear and tear can also break those sensors, springs have a rated lifespan after which they can snap or the spring constant just isn't accurate anymore.

From looking at the wiring diagram I can also tell you the pinout of the 6 pin sensor connector for the g-sensor is 100% identical between the GTR and the GTST A-LSD. The only difference is that the ATTESA has two longitudinal sensors for some reason while the GTST only uses one. 

[jacobzking]

18 minutes ago, joshuaho96 said:

I'm not really sure what you're saying when you said you ran through the flow chart. Pin 92 appears to be a ground. I would verify that has a good connection. Pin 27 and 29 relative to ground should be 8V as you said. For the GTST single plug if pin 27 and 29 are +8V then 26 and 28 should be the signal output. Verify that the supply voltage stays at roughly 8V with the sensor connected. Then verify that the voltage you get at pin 27 and pin 29 is also what you expect. On a flat table not moving it should be 2.5V. Then check against pin 40, 41, 42, and 43 on your A-LSD control unit. On the g-sensor those are equivalent to pin 27, 26, 28, and 29 respectively if I'm reading the wiring diagram correctly that I linked in my previous post. Should be page 28 of 31 where the A-LSD/ABS control unit pinout is shown. If you can't find it see below:

If you have verified the signals are making it through the harness ok with everything connected up then yes, if you aren't getting about 2.5V from the signal pins relative to body earth you have a dead sensor. It's also not that unlikely because it is basically a glorified pendulum with some springs in there attached to a potentiometer to measure position. If someone dropped the sensor at any point from when it was built to any number of shipping depots and junkyards between the point of manufacture and you over the past 3 decades it's possible that the potentiometer breaks or the springs are permanently deformed and it'll read weird values just sitting there. The red shock sensor not reading excessive force is not proof that the sensor works. Just plain wear and tear can also break those sensors, springs have a rated lifespan after which they can snap or the spring constant just isn't accurate anymore.

From looking at the wiring diagram I can also tell you the pinout of the 6 pin sensor connector for the g-sensor is 100% identical between the GTR and the GTST A-LSD. The only difference is that the ATTESA has two longitudinal sensors for some reason while the GTST only uses one. 

you da man!

[jacobzking]

Update: after 3 "faulty" used OEM sensors, I tried one of the DoLuck aftermarket/digital for a GTR (I had to modify the connector plug) sensors and now my error 65 code is GONE! (65 G- sensor 2 power supply and circuit) and I'm just left with these 2...

62 FR and RR G sensor 2 and circuit

66 Side G sensor and circuit

 

So it looks like maybe it was a bunch of old bad, sensors after all.  Not to track down these 2 errors codes.

[Duncan]

Good persistence, and thank goodness there are (better) aftermarket options to keep these cars working today

[joshuaho96]

2 hours ago, jacobzking said:

Update: after 3 "faulty" used OEM sensors, I tried one of the DoLuck aftermarket/digital for a GTR (I had to modify the connector plug) sensors and now my error 65 code is GONE! (65 G- sensor 2 power supply and circuit) and I'm just left with these 2...

62 FR and RR G sensor 2 and circuit

66 Side G sensor and circuit

 

So it looks like maybe it was a bunch of old bad, sensors after all.  Not to track down these 2 errors codes.

Still the same deal, follow the diagnostic workflows posted earlier in the thread. If you can verify it's getting the right supply voltage and then verify that the signal outputs are sane then it's either a harness fault or your A-LSD control unit is damaged somehow.

[schalachi]

Hi my chassis is ECR33-029657 how do I know if I have active LSD?

[r32-25t]

Stick your head under the rear of the car and have a look 

[Duncan]

20 minutes ago, r32-25t said:

Stick your head under the rear of the car and have a look 

that really is the easiest.

there have been some threads on here to decode the model code if you want to check that, I just had a quick look in FAST and the decode section there does not cover all digits in r33 GTST; the digits it does cover don't include the ALSD option

 

[joshuaho96]

On 3/22/2024 at 10:18 AM, schalachi said:

Hi my chassis is ECR33-029657 how do I know if I have active LSD?

If the rear diff cover is finned and your gauge cluster has an A-LSD warning light you have the A-LSD.

[schalachi]

On 3/25/2024 at 9:44 PM, joshuaho96 said:

If the rear diff cover is finned and your gauge cluster has an A-LSD warning light you have the A-LSD.

Thanks. Mine does not.

[R32RB20]

On 08/11/2023 at 6:09 AM, jacobzking said:

Update: after 3 "faulty" used OEM sensors, I tried one of the DoLuck aftermarket/digital for a GTR (I had to modify the connector plug) sensors and now my error 65 code is GONE! (65 G- sensor 2 power supply and circuit) and I'm just left with these 2...

62 FR and RR G sensor 2 and circuit

66 Side G sensor and circuit

 

So it looks like maybe it was a bunch of old bad, sensors after all.  Not to track down these 2 errors codes.

Thank you for posting a follow up with the fix it really helps others when they are having the same problems