What it means
The control circuit B of the battery charger coupler status indicator reports a control circuit high condition. Charging status display impaired.
At a glance
- Usually lights the check-engine light
How it works
The charger coupler status indicator uses control circuit B to display charging or coupler status. The control module monitors the signal level and sets P0D8B when circuit B is higher than expected, which may result from a wire shorted to battery positive or an open indicator path.
Common causes
Most likely first.
- Wire shorted to B+
- Open lamp
Symptoms
- Coupler status indicator may not work correctly
How to diagnose it
- Use a scan tool to save freeze-frame data and check whether circuit B is reported high during an indicator command or charging attempt.
- Observe the coupler status display and note whether the circuit B indication is absent, stuck, or otherwise abnormal.
- With the vehicle powered down according to the manufacturer's procedure, inspect circuit B wiring for damage that could contact a battery-positive feed.
- Inspect circuit B connectors and the indicator element for an open connection, backed-out terminal, corrosion, or damage.
- Test circuit B for an unintended connection to battery positive and check continuity through the indicator path using the manufacturer's procedure.
- If wiring and the indicator path pass, test the control module connector and circuit B output.
Common fixes
- Repair circuit B wiring shorted to a battery-positive feed.
- Reconnect or repair an open circuit B connector or terminal.
- Replace the indicator element if it is open.
- Repair the circuit B module connection if testing identifies the fault.
Can I keep driving?
The coupler status display may not reliably show the circuit B state, though this code alone does not confirm that charging has stopped. Check charge status elsewhere on the vehicle and stop if a separate charging fault appears.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.