ABS Error Codes 71 to 78

[2win2rbo]

I have recently upgraded from auto transmission to 5 speed manual. After a while, the ABS light went on and yes, the brakes are locking already. Codes 71 to 78 mean low voltage and incorrect voltage on all four wheels. I have not touched the rear wheels during the conversion or the abs system. Is it possible that there's an open circuit in one of the abs wheel speed sensors?

[toyomoho]

What are the codes: 71 and 78 or 71 thru 78.

If open circuit in one sensor the code would be for that sensor such as: code 38, open circuit in right rear sensor.

This could be a wiring issue.

[new echo owner]

How did you pull the codes? Those codes, I think, are for the speed sensor input test. Clear the codes and see if they reset.

N.E.O.

[2win2rbo]

Originally Posted by new echo owner

How did you pull the codes? Those codes, I think, are for the speed sensor input test. Clear the codes and see if they reset.

N.E.O.

You're right, that's for the speed sensor diagnostic test. I found a main loose ground cable underneath the air filter box, connected it and those codes did not appear again. I redid the Tc, E1 diagnostic check and I had ABS trouble code 32 which is: Left Front Signal Malfunction. I'm going to have a look at the sensor tomorrow. I think I may have greased the area quite a lot before I put the CV in.

[new echo owner]

If you didn't disconnect the sensor or unbolt the retainer on the wheel well, there is a good chance that the harness to the sensor is damaged.

N.E.O.

[ASG14]

^ Yeah, I did the SAME thing when I replaced an axel, my stupidity. Same wheel too, lol.

Replaced the ABS speed sensor 1 1/2 years later (few weeks ago actually), and all fine.

[2win2rbo]

Does the gen 3.5 have sensor rings (that goes with the CV) for the ABS wheel speed sensors? I don't remember pulling one out.

[new echo owner]

It is part of the outer joint on the axle shaft, unless you had put in a different axle, there is no reason that would change.

N.E.O.

[Nervous]

Sorry to recover the old thread, but I have the code 71 after Ts-E test as well. What was the culprit after all?

[2win2rbo]

Originally Posted by Nervous

Sorry to recover the old thread, but I have the code 71 after Ts-E test as well. What was the culprit after all?

ABS Code 71 means that the right front speed sensor is getting insufficient voltage. When I had the code I just checked for a loose grounding around the engine bay. After reinstalling a loose ground wire, I reset the ABS and the code's gone.

[Nervous]

Thx! And resetting ABS computer is just disconnecting/connecting back the big ABS connector?

[2win2rbo]

Originally Posted by Nervous

Thx! And resetting ABS computer is just disconnecting/connecting back the big ABS connector?

There's a better way to do that.

You can
1) put a jumper wire on Tc and E1 on DLC1;
2) remove the short pin (from DLC1 as well);
3) Turn the ignition switch on;
4) depress the brake pedal 8 or more times within 3 seconds;
5) check that you have the normal code or that the codes are erased; and
6) put the short pin back.

[TedL]

Originally Posted by 2win2rbo

There's a better way to do that.

You can
1) put a jumper wire on Tc and E1 on DLC1;
2) remove the short pin (from DLC1 as well);
3) Turn the ignition switch on;
4) depress the brake pedal 8 or more times within 3 seconds;
5) check that you have the normal code or that the codes are erased; and
6) put the short pin back.

Is step 4 correct as written? Seems awfully fast to get through 8 cycles.

[2win2rbo]

Originally Posted by TedL

Is step 4 correct as written? Seems awfully fast to get through 8 cycles.

Yes it has to be awfully fast.

[Nervous]

But what exactly does this reset? I don't have ABS code (I mean, ABS light is not ON all the time, I have code 71 only after doing Ts-E test; but it is not stored in ABS ECU, I think). So, is the reset still necessary?