Guidance needed 2005 Hino 268 ABS

[Trkmed]

Hello,
I recently acquired an 05 Hino 268 with Allison transmission. The truck had low power and The ABS light on.
i am thinking the two are related. I have no code reader for this truck but pulled the blink codes.
hydraulic brakes ABS code 2-2 left front modulator valve I checked the ohms on the truck side
and both valve checked good. How do I tell if the ABS module is bad or if it’s something else?
after the batteries where disconnected and truck moved the ABS tight went out , however as it was idling
for 5 minutes the light came back on.

thank you

 

[Hino123]

If the ABS light is on the torque converter will not lock up. I have Meritor software that I use. Diagnosis by blink codes only can be tricky. The service manuals are available for free from Meritor Wabco. I would get the proper service manual and go diagnose the blink codes from there.

 

[Trkmed]

Thanks, I Do have the manuals, but I cant seem to find the part that talks about the ABS module failure Or troubleshooting the module.
i don’t mind getting the software but I am trying to keep cost on the low end as the truck is not a money maker for me.
just for fun

 

[Hino123]

You need use the diagram in the manual, load test ALL powers and grounds at the module. Verify the data link is operational, check Can resistance 60 ohms and check your cab voltages for your high/low split. 2.6v high and 2.4v low. Roughly. If you have all that then try a test module if you have a sister truck. That’s how I check my modules. I’m slightly confused though as you said you tested the modulator valves and also stated it was a hydraulic brake truck. Where is the ECU on this truck or is it hydraulic or air brakes ?

 

[Trkmed]

Hydraulics, modulation valve ohm ok , control unit in the cab under fuse panel right side of dash.
I am using the wabco maintenance manual 39. Maybe a more complete manual is out there.
i just have the single truck as it was basically given to me.

thank you for your time.

 

[Hino123]

PM me the vin. Somethings not jiving here. The ABS module is attached to the pump motor on the frame on hydraulic brake trucks. The abs ecu for air brake trucks is mounted in the fuse relay center. This is a 05 so I could be wrong but a complete vin would straighten it out on my end.

 

[Hino123]

Here is the manual for a cab mount D Version ECU. Follow the trouble tree and ohm out the valves from the grey X1 connector. Inlet valve and outlet valve resistance. This will tell you if it is the ecu or the wiring from the valve to the ECU. At the bottom of the valve it pins out the inlet valve (IV) and (OV) outlet valve. The modulator/pump assy is on the lh of the frame behind the cab. Let us know what you find.

 

[Trkmed]

I am thinking it is the ECU as the modulator itself pin out as good on the modulator pin 8 and 13 outlet valve is about 3.4 ohms
pin 8 and 12 inlet valve is about 6.4 ohms (unplugged.) the ECU end of the harness with the modulator plugged in is pin 3 and 2
inlet valve 6.5 ohms and pin 3 and 1 outlet valve 3.5 ohms.

time to start looking for an ECU?
thoughts please

 

[Hino123]

Yeah sounds like you got it basically covered. You could load test the wires from the ECU to the pump just to 100% verify the integrity of the wires, it sounds like the modulator resistance is correct though. You could un pin the lh side and swap the pins to the rh side and see if the code follows or stats the same. If it stays then you know it is the ECU. I would load test ALL the powers and grounds just be sure. Then if all that checks out. Maybe look on Ebay for one out of a wreck????

 

[Trkmed]

Okay,
so I switched the pins from R/F to L/F and the code comes back as 2-2 , I clear the codes and after about 2 minutes off idle time the abs light is on it’s the 2-2 code, I will be looking for a control unit.