Abs Light On, Avensis 2000 1.8 Vvti (Does My Harness-Side Abs Ecu Conn

[Avensis Dan]

Hi All,

My first post on the TOC forum! Wish I'd been here a lot earlier.

In short:

• Four weeks ago had my mechanic run diagnostics on ABS light. He changed the ABS ECU pump, but couldn't 'talk' to the car computer to clear the code. Went to Toyota, but they didn't know what the problem could be. Wife and I spent Easter weekend with the service manual, trying different tests, and trying to clear the code manually. Current hunch is pointing to the harness-side ABS ECU connector needing to be replaced.

Our car spec:

• Toyota Avensis 1.8 Vermont VVTI Petrol (2000) 5 door hatchback, right hand drive (originally bought in UK, imported to Sweden)

Question:

• Does my harness-side ABS ECU connector need replacing?

The long version:

After almost four weeks of troubleshooting the ABS light, I need some OBJECTIVE advice to fix get the ABS light off, and the ABS functional again.

History of issue:

1. Nov. 10, 2013, a mouse hole appears in the RHS passenger arm rest upholstery (by the door). (I didn't realise until two days ago that the right rear (RR) ABS sensor cabling and junction connector was routed under side of the seat)

2. Nov. 15, 2013, I take the car to my mechanic with an ABS light on. He says its probably the pump, but needs to do more diagnostics. I say we'll wait until after winter.

3. Mar. 10, 2014, mechanic says the ABS ECU (modulator pump) needs changing. Quotes £360 for a new one. At the same time, he can't read the error code.

4. I ordered a second-hand ABS ECU through from the UK (Orange Autosalvage via 1stChoice.co.uk)

5. Mar. 25-28, 2014, mechanic changed the ABS ECU, but the ABS light is still on. He blames the old pump, and can't get his OBDII to communicate with the car brakes to clear the code.

6. Apr. 4, 2014, car goes to Toyota service centre, but they can't get their diagnostics to talk to the car's computer either. They go through the "Terminals of ECU" sheet (DI-134 in the Diagnostics section of Service Repair Manual).

Results are that wrong voltage reading on Ts (A6 - 11) - GND (A6 - 16, 19) of 3.30v. They couldn't say how long it would take to find the problem.

7. Apr. 11, 2014, took it to another garage who also couldn't get their OBDII diagnostic to talk to the computer. At least they didn't charge.

8. Apr. 17, 2014, took the car home, and spent a long Easter weekend with the Haynes manual, the Avensis Service Repair Manual 1997-2003, YouTube and Google!

9. Apr. 20, 2014, discovered the mouse mess whilst looking for the rear right sensor connector. Both sensor side cables chewed right off, and one damaged after the connector. Both fixed. ABS light still on. Manual reset tried.

Checks / tasks done:

• continuity of sensors and cables to ABS ECU connector - All OK

• continuity and physical inspection of sensor connectors - All OK

• tried to (unsuccessfully) clear code by putting jumper wire from port 4-13 on DLC3 (OBDII port) under steering wheel. Turn on ignition. Depress brake pedal eight times within 3 seconds. Turn off ignition. Pull out jumper wire. Turn on ignition. - Not Good

• drove 3 miles after that to 'reset' ABS. - Not Good

Problems:

On the ABS ECU connector, there is no continuity between TS and GND. From the Avensis Service Repair Manual, it's telling us to change the connector. Has anyone had this done?

(Mechanic recommends us to get the old ABS ECU refurbished and reinstalled. That's a £500 experiment I'm not going to do. He says the connector looks good, and hardly ever needs replacing - but can be replaced).

Appreciate any advice!

[Avensis Dan]

The manual check gives blinks out the error code as 36.

[Konrad C]

Hi Dan,

I have to admit limited knowledge to your issue, but googled the following link - http://www.toyotaownersclub.com/forums/topic/47053-abs-and-speed-sensor-diagnostics/

This may answer some of your query.

You mentioned mouse. Have you had the car interior stripped out to access the wiring. The mouse may have chewed a few cables.

When the abs light is on for a reason, once that reason is cleared, the car has to be driven over 10 mph at a distance of over 30 metres to reset the light.

I have not read all the long part of your post, but your short version seemed to cover the subject. Many apologies.

Hope you find the problem without too much time and expense .

Konrad

[Avensis Dan]

Hi Konrad,

Thanks for replying, and for the link.

Admittedly, I haven't stripped the whole car, but I have done continuity tests from the DLC3 and the ABS ECU connector as well as from the sensor junctions to the ABS ECU connector. All showed continuity with the multimeter.

The only broken link is between TS and ground.

I took it to another Toyota service centre today to confirm our suspicion that the ABS ECU connector needs replacing. There's a limit to our DIY diagnostics!

I'll try the 10 mph tip once I get access to the car again.

Fingers crossed!