Hino 268A P0045 VNT Turbo Actuator Open Circuit - No Boost

Question

My 2014 Hino 268 is stuck in limp mode and throwing a constant P0045 code. The truck has zero power on hills and the turbo actuator doesn't seem to be cycling when I cycle the key. I am worried the VNT controller is fried or there is a break in the harness.

wrenchqueen · Accepted Answer

The issue was a broken power feed wire inside the loom approximately 6 inches back from the actuator plug. I performed a 'wiggle test' while monitoring voltage and found the break. I spliced in a new section of 14AWG wire with a heat-shrink butt connector and secured the loom with heavy-duty zip ties to prevent future rubbing. Total cost for the repair was under $10 for materials plus two hours of diagnostic time.

road_rambler · Answer

Check the wiring harness near the back of the cylinder head. These Hinos are known for the loom rubbing against the lifting eye or the fuel rail, which can chaff the signal wire for the VNT actuator.

turbo_tony · Answer

You need to use a multimeter to check for 24V at the actuator connector pins. If you have power and ground but the actuator isn't moving during the startup self-test, the internal motor inside the VNT housing is likely seized.

Sam Holloway · Answer

Have you checked the VNT linkage for carbon buildup? Sometimes the vanes get stuck and the motor draws too much current, causing the ECU to shut down the circuit and throw the P0045 open circuit code as a safety measure.

Hino 268A P0045 VNT Turbo Actuator Open Circuit - No Boost

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