A question on SRS ECU interchangeability

[yarihari]

Hi - I hope someone will be able to help me before I go and do something daft!

I have a solid SRS warning light on my 2002 Yaris T-Sport. With help from the forums here, I have pulled the 31 DTC pointing to the SRS ECU as the problem. The reset procedure appears to work but the code remains, and all connections look good under the seat and to the ECU.

Unfortunately I am struggling to find an identical second-hand SRS ECU (89170-0D010), and I have inadvertently been sent a different one (89170-52090) by a seller, although it has come from the same car.

My question is this: if I fit this other SRS ECU, is there a risk that I could cause more damage?!

Thanks!

[CTScott]

89170-0D010 is for an 01 to 03 3 door Yaris.

89170-52090 is for a 99 to 01 3 door Yaris.

Both indicate driver, passenger and side impact airbags. From my experience experimenting with 2nd generation Yaris SRS ECUs (and figuring out how to reset the crash data EEPROM within them), I believe that the 52090 will be OK in your car. It won't do any damage and in a worst case will complain about a missing sensor.

[yarihari]

Thanks for this, and also your other guides on getting the DTC out. Invaluable stuff :-)

I had a go but the middle connector is of a different size. I will try another model and will post an update later.

[CTScott]

Thanks for this, and also your other guides on getting the DTC out. Invaluable stuff :-)

I had a go but the middle connector is of a different size. I will try another model and will post an update later.

Interesting. So the connector D4 (the middle one of the 3) was different? Did it have more or less pins, or was the plastic housing just physically different?

On the US 1st gen Yaris (aka Toyota Echo) D4 is identical from 1999 through 2005.

[yarihari]

Yup, it has more pins although some of them aren't is use. The middle plug on the 89170-52090 is 8 pins wide, and the 89170-0D010 I think is 11 pins wide.

[yarihari]

A wee update... I tried fitting an 89170-0D100 which I thought had a similar airbag configuration (drivers, pax, & side) but this came up with DTC's 31, 32 and 33. It also kept blowing the ECU-IG fuse which brought the ABS and handbrake warning lights up.

I was thinking I might try a 89170-52140 next - if I can get the drivers & pax to work I'll be happy.

[CTScott]

A wee update... I tried fitting an 89170-0D100 which I thought had a similar airbag configuration (drivers, pax, & side) but this came up with DTC's 31, 32 and 33. It also kept blowing the ECU-IG fuse which brought the ABS and handbrake warning lights up.

I was thinking I might try a 89170-52140 next - if I can get the drivers & pax to work I'll be happy.

52140 is for a 2002 Japanese built Yaris
0d100 is for a 2003 JDM or French 5 door Yaris