How To Fix A Hydrogen-powered Vehicle With An Insulation Fault?

Jul 13, 2023

Truck Model:

QINGLING FCEV (Fuel cell electric vehicle) GVW 8.3ton.

 

 

Problem Description:

Insulation alert popping out during driving.

 

 

Analyse & Diagnostic:

Press the T3O low voltage switch and remove the BMS maintenance switch;

2. Unplug the EAC plug, then a resistance of 0.18 megohms detected;

3. Takeout the multi-combined to boost DCDC high-voltage harness, then the resistance value of 0.18 megohm at the multi-combined end detected;

4. Check the high-pressure parts on the multi-combined harness one by one; the resistance value of the directional booster pump and the high pressure wiring harness is detected to be too low, and there are visible water drops at the joints.

 

 

Troubleshooting:

1. Replace the directional power pump and its wiring harness; add power steering oil, then check for any leak, and drain out after;

2. Confirm that the whole vehicle’s insulation resistance value is 3.0 megohms, and no more alerts.