ABS Code 5

I read out the error code and the reported code 5. I have followed the troubleshooting steps that are Haynes repair manual and come to the point where it says that I should change the ABS modulator from behind to front, to determine if it is the modulator or ABS control unit which is defective. Both these parts cost a whole lot of money here in Norway (3.000, - USD for both). What I'm wondering is if there is anyone out there have any tips about other things I should check before I go to the step of buying new parts. The bike is a 2003 model.
Best regards
Tore

Tore, have you have tested your brakes & confirmed that the ABS is not working?

Hi
Front and rear wheels are blocked when I brake hard enough. Tested it on a gravel road at low speed.Forgot to say that ABS light comes on as normal when I start, and starts blinking when I get up in about 10 kmh
TT

Check to make sure that the ABS sensor is not covered in dirt or bugs as I got my ST stuck in the mud once and got the sensor covered with mud and my ABS light was flashing until I cleaned it.

This is a very good idea. Norway has a wet climate.

A buddy had this happen on his Concurs......flashing ABS light. The dealer cleaned the sensor the 1st time. He cleaned it the second time. It was caused by wet roads & a film of dirt/magnesium chloride.

It was in the Spring. Here in Colorado, we spray magnesium chloride on the roads to melt ice. The magnesium chloride was still on the roads in early Spring, is water soluble, & puts a thing film on everything.

Hi
I have taken the sensors on the wheels and cleaned them, but ABS light is still blinking
I live in Northern Norway and despite long winter there is little chemical treatment of roads to melt snow. I may mention that my bike is imported from USA 3-4 years ago.TT

Code 5 is a problem with the rear modulator. If the computer isn't showing any other fault codes, the sensors and everything else are fine.

The change-the-modulators step doesn't require buying any parts. Drain the brake lines, remove modulators and re-install them in the opposite location (i.e., the rear one goes where the front one was and vice versa).

Before you do that, two things:

First, could you outline the troubleshooting steps you've been through? The Haynes manuals sometimes come up short compared to what's in the Honda manual, and if there are steps missing, those should be covered.

Second, given the age of your bike, there's a fair chance this problem is related to crud buildup in the connections. I'd disconnect and clean all of the connections involved with a good contact cleaner. If you can get CRC QD or Caig DeoxIt in the Great White Norge, try either of those; otherwise, find out what your local electronics repair people use. (WD-40 is not a contact cleaner.) The connections to clean should be two where the modulator mates with the wiring harness and the black, 12-pin connector on the ABS computer.

--Mark

I have done everything under "Fault code 5" except no. 26 and everything is ok. 26 was the next step. Attaching a picture of the manual

All contacts related to the modulator and ABS controller is controlled and is apparently okay. No dirt and completely clean.
The bike is a 2002 model first registered in 2003.

That's close to what's in the Honda manual, so I'd say the two things left to do are clean the connections and a modulator swap.

These bikes don't have a history of chucking ABS computers. The modulators 1100s did have some problems with crank angle sensor failures as they aged, so it's possible the ones on the 1300 have the same problem and are just getting old enough to show it.

By the way, I re-read the entire thread and spotted a couple of things that didn't add up:

I may mention that my bike is imported from USA 3-4 years ago.
...
The bike is a 2002 model first registered in 2003.

Click to expand...

Not that it matters for this discussion, but the first model year for the 1300 in North America was 2003.

--Mark

The original poster list he owns a 2003.

The police model, ST1100, was available in the US in 2003. 2002 model were left overs in 2003.

We need to know for sure which ST we're talking about.

I didn't read the whole trouble shooting process. Is one of the steps to disconnect the battery and reconnect it a short time latter (5 minutes)?

My bike was imported as a used motorcycle, according Chassis No. is the produced in 2002 and it is first registered in 2003 .........
I have not tried to disconnect the battery and reconnect after 5 minutes.
There is a ST1300, according STwiki and the parts catalog located there
Best reg
Tore T

I found a used ABS modulator on Ebay at a reasonable price, and ordered this. It was from a 2007 mod, and as far as I could investigate, it should fit, and it did.
Put it in, aired only rear brake (both nipples) from foot pedal, deleted error codes and took a test ride. Everything ok, ABS lamp lit properly but extinguished when I came up in about 10 Kmh.
Dismantled the old modulator and as you can see from the picture was the rust / corrosive inside. Looks like there's been an internal leak of brake fluid that has caused this.
Tested with heavy braking on gravel and ABS sytem works.

Nice to know that you found the problem and got the bike back on the road.

Glad you diagnosed the problem & got it fixed.

Can the modulator be repaired?

Thanks for posting the pictures of the innards. That's useful.

--Mark

Had this same issue on my 05. Swapping the modules was the fix. I think the double fluid flush was really the fix but what do I know.
Brian
Canoe BC

I've only had one problem with ABS and that was with my ST1100. The ABS turned out not to be the problem despite the codes it was throwing. It was just the symptom of something else. The ABS system is very sensitive to voltage fluctuations and I had an aftermarket relay that was going south on me at the same time. I replaced the relay with a new one and the ABS problem disappeared. No more flashing ABS light and now more codes.

Makes sense, if the parts are frozen or dragging the angle sensors can't provide a proper self check . Some of the newer Honda Sport Bikes have over $6500.00 worth of brake parts , you would not want to skimp on the brake fluid changes on those units or any other complex brake system , I would do mine every year depending on the conditions, cheap insurance. Here is some tech on the system.


Modulator motor control:
The ABS control unit monitors both the two wheel speed sensors and the two modulator crank angle sensors that provide
precise readings of each modulator’s crankshaft positioning (i.e., control piston position). The ABS control unit
directs its motor driven control signals (control unit with the built-in motor driver) to deliver high-amperage electrical
output to the control motors and thus operates the system.
• Self-diagnosis function:
The dual-CPU configuration ensures instant recognition of computer-related malfunctions, since the two CPUs run constant
checks on each other whenever the ignition switch is turned to “ON.”
When the ignition switch is turned to “ON,” the ABS control unit evaluates its internal circuits. The indicator blinks
when an abnormality is detected in the system. When the system is normal, the ABS indicator stays on indicating that
the ABS control unit is in the stand-by mode for the wheel speed sensor and modulator crank angle sensor signals. The
wheel speed sensors send signals to the control unit after the motorcycle starts to move (approximately 10 km/h or
above), then the control unit evaluates the system condition by activating the modulator control motors and receiving
signals from the crank angle sensors. The ABS indicator goes off when the system is found to be normal.
The control unit monitors its main functions while the motorcycle is moving, whether the brakes are engaged or not.
When it detects a problem, the ABS indicator blinks.
• Change-over function:
When the ABS control unit detects a problem through its self-diagnosis function, it stops the ABS function. The back-up
spring in the modulator pushes the control piston automatically to open the cut-off valve and restore conventional
brake operation.
• Problem code storage function:
Problem codes can be memorized and stored in the ABS control unit (up to two codes), and can be retrieved and indicated
by the number of times the ABS indicator blinks.