P0D18Battery Charging System A High Voltage Interlock Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- P0D18 flags a charging HVIL signal that sits too high. On the Chevrolet Volt and Cadillac ELR GM tests the loop in two states: with the 5 V source off, a sensed level above 24 % of reference (5 of 6 samples in 2011, 5 of 8 for 2014 and ELR), and with it on, a level above 44 % (4 of 6), set the code as Type A, MIL after one trip. A high value may point to a break or added resistance in the loop or a short to a voltage. Polestar stores P0D1800 in the BECM of the 2021–2023 Polestar 2 with a propulsion warning and resolves it with BECM software 2.10 (TJ 36713). Kia lists P0D1812 for the 2023 Niro EV among the codes that lead to ICCU replacement (bulletin 298). The low case is P0D17, the open loop P0D15.
- What you may notice
- Malfunction indicator lamp (GM Type A)
- Propulsion or high-voltage warning in the cluster
- Slow or no AC charging
- Likely causes
- PossibleHigh resistance or partial break in the interlock loop
- PossibleBattery module software needing an update (Polestar 2)
- PossibleFaulty integrated charging unit (Kia Niro EV ICCU)
- RareInterlock wire shorted to a voltage source
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €50 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.