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ABS Blinking


Krishnaprasad
06-30-2023, 11:08 AM
Greetings!,
I am new to this automotive forums hope some one can help me with an issue that i am facing,
a customer came in with this following complaint: Vehicle turning off abruptly on slow speed, Check engine light and ABS is blinking.

The vehicle specifications is as follows:
Make: Toyota
Model: Hiace
Year of Manufacture: 2014
Gear box type: Manual
Engine: 2tr
ECU number: M6

upon connecting diagnosing tool no Engine code is shown, surprisingly in the initializing screen it is shown that ABS not equipped, i looked to confirm if the abs system was equipped, it was equipped in the vehicle, I went into generic EOBD to check but the system failed to run every protocol then i checked the ECU unit to see if it was tampered with there was a external wire that is being connected to a romatic DBW speed limiter. I Also noticed that the Check engine light was blinking constantly but the ABS light was blinking in a pattern indicating a code i guess, the pattern is as follows:

3 blink pause 1 blink pause
3 blink pause 2 blink pause
3 blink pause 3 blink pause
3 blink pause 4 blink pause
4 blink pause 1 blink long pause

I have checked the wiring to the speed limiter to double check if any loose connection is making the issue. but, the connection seems to be fine. I removed and reconnected the ABS Control unit wire to check for loose wire, bend pin, dust etc. Then i checked if any cracked wheel speed sensor is making the issue, here also the sensor looks pretty ok (Physically looks ok and sensor sticks to a metal, DID NOT check with a multimeter), i removed the ECU of this vehicle and put the ECU to another vehicle of same make model that started up just fine with no trouble code, indicating that the ECU is fine.

what can be the most probable cause, and any advice on how should i proceed with diagnosing the vehicle

any help would be appreciated greatly


Krishna Prasad

fredjacksonsan
07-01-2023, 07:58 AM
Welcome!

Based on "shutting off at low speed" and the other ord things, I would look for loose electrical connections first. Did the customer install anything new before the problem? (I know a guy that had a poorly installed speaker that touched the ECU, and the magnetic field caused shutdowns)

Krishnaprasad
07-01-2023, 10:35 PM
Welcome!

Based on "shutting off at low speed" and the other ord things, I would look for loose electrical connections first. Did the customer install anything new before the problem? (I know a guy that had a poorly installed speaker that touched the ECU, and the magnetic field caused shutdowns)

Thankyou for the insight fredjacksonsan

The issue was resolved, the vehicle had a speed governor that was connected to multiple ECU wires by back probing. this was an old unit according to the customer, after seeing your comment i asked him if it has been tampered with. it seems that he had taken it to another technician and he had removed the governor to access the evaporator/blower casing instead of unbolting the module and keeping it aside he decided to cut the wires and slide it aside.

upon refitting the unit he must have messed up connections as there was 2 green wire one indicating speed sensor one indicating POS i just removed the unit as a whole and started her up all lights gone.

now i have ordered another speed governor that is easy to install and have simple wiring connections.

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