What this code means
B1080 may indicate that the relay control module and body control module do not agree on the IG1 ignition power state.
What the vehicle may do
- The vehicle may show body-electrical behavior related to ignition ON status.
- Some functions can appear inconsistent if the module sees an ignition-state mismatch.
Possible fault areas
- Possible IG1_METER power feed circuit issue.
- Possible connector or terminal condition in the related circuit.
- Possible body control module fault area.
Diagnostic path
Opening context
For B1080 on this Civic, think of it as an IG1 power supply plausibility problem between the relay control module and the body control module. The vehicle may have body-electrical behavior that changes with ignition state, because the module is comparing the hard IG1 input against the IG1 message it sees over B-CAN. Broadly, the fault area can include the IG1_METER power feed circuit, related connector or terminal issues, or a possible body control module problem. Start with the basic system checks, and if other codes are present, check what they mean first so you do not chase this code out of order.
How the code sets
The logic for this code is a comparison. If the relay control module sees a difference between the IG1 signal input and the IG1 signal coming from the body control module over B-CAN for the required amount of time, it judges that as abnormal and stores B1080. So the diagnosis is not just asking whether ignition power exists. It is asking whether the circuit state and the network-reported state agree.
Reproduce the operating condition
To confirm the condition, turn the vehicle to the ON mode, then wait for at least 6 seconds. That gives the module time to run the comparison before you move into the circuit check.
Run the IG1_METER check
Next, use the HDS function for IG1_METER Circuit Inspection. Perform the inspection at body control module connector A, the 66P connector, using the female terminals, with IG Mode connected. The normal condition for the IG1_METER circuit inspection is ON with 12 V battery voltage, circuit type 1.
Use the result to choose the path
If the IG1_METER circuit inspection is abnormal, treat it as a circuit problem. If the power supply inspection shown in the table is abnormal, continue with the additional Power Supply Inspection to locate the failure. If the IG1_METER circuit inspection is normal, the diagnostic path points toward a problem with the body control module. Do not guess past that split; let the IG1_METER result decide the next move.
Takeaway
The takeaway on B1080 is simple: confirm the ignition state, run the IG1_METER inspection, and separate a circuit-side fault from a body control module-side fault based on that result. For more diagnostic training, visit stepdiagnostics.com.
Final check
This code often comes down to checking whether the IG1 circuit state matches what the module network is reporting, then following the circuit result instead of guessing.
For more guided automotive diagnostics, visit STEP Diagnostics.
