What this code means
B1077 may indicate that the MICU is not seeing the windshield wiper motor park signal as expected.
What the vehicle may do
- The wipers may not work correctly.
- The wipers may not park correctly.
- The code can be intermittent even when the wipers appear to work at the moment.
Possible fault areas
- Possible wiper motor issue.
- Possible park-signal circuit issue.
- Possible wiper power feed, ignition feed, or ground issue.
- Possible relay circuit board or related wiring issue.
- Possible MICU or under-dash fuse and relay box issue.
Diagnostic path
Opening and code meaning
On this 2010 to 2017 Honda Accord with the 2.4 gas engine, B1077 points to a windshield wiper motor park signal error in the MICU and front wiper circuit. In plain language, the control unit may not be seeing the wiper park signal the way it expects. The driver may notice the wipers not working correctly, not parking correctly, or the fault may show up during a scan even if the concern is intermittent. The possible fault areas are the wiper motor, the park-signal circuit, the wiper power and ignition feeds, ground, relay circuit board, wiring between the relay board and under-dash fuse and relay box, and the MICU inside the under-dash fuse and relay box. Work this one in order, because the first split is whether the wiper motor actually runs.
Start by reproducing the operating conditions
Start by clearing the DTCs with the HDS. Cycle the ignition to LOCK (0) and then back to ON (II), or use the engine start/stop button to go OFF and then back ON. Turn the windshield wiper switch to LOW or HIGH for 15 seconds or more, then turn the switch OFF. Now answer the first question: does the wiper motor work? If it does, go straight into code confirmation. If it does not, skip ahead to the fuse and feed side of the diagnosis.
Confirm whether B1077 returned
If the wiper motor works, check for DTCs with the HDS. If B1077 is indicated again, continue with the wiper motor park-signal test path. If B1077 is not indicated, treat it as an intermittent failure; the system is OK at this time.
Check the wiper motor AS signal path
With the ignition in LOCK (0), or the start/stop system in OFF mode, perform the windshield wiper motor test. The key question is whether the motor runs and pulses normally. If it does not run and pulse normally, replace the windshield wiper motor. If it does run and pulse normally, move to the FR WIPER AS line check.
Check the FR WIPER AS line for an open or short
For the FR WIPER AS line, disconnect the windshield wiper motor 4P connector and under-dash fuse/relay box connector E (36P). Jumper windshield wiper motor 4P connector No. 4, WHT, to body ground. Then check continuity between under-dash fuse/relay box connector E (36P) No. 28, WHT, and body ground, with the ignition in LOCK (0) or OFF mode. If there is continuity, repair a short to ground in the wire. If there is no continuity, repair an open or high resistance in the wire.
If the wiper motor did not work, check the fuses first
If the first check showed the wiper motor does not work, check fuse No. A12-8, 30 A, at the under-hood fuse/relay box, and fuse No. B12, 7.5 A, at the under-dash fuse/relay box. If both fuses are OK, continue to the power feed checks. If either fuse is not OK, replace the fuse. If the fuse blows again, repair the short to ground in the No. A12-8, 30 A, and/or No. B12, 7.5 A, fuse circuit.
Check the +B WIPER feed
Next, disconnect relay circuit board connector B (14P). With the ignition in LOCK (0) or OFF mode, measure voltage between relay circuit board connector B (14P) No. 10, RED, and body ground. If there is battery voltage, the +B WIPER wire is OK and you continue. If there is not battery voltage, repair an open or high resistance in that wire.
Check the IG1 WIPER feed
Now disconnect relay circuit board connector C (10P). Turn the ignition to ON (II), or select ON mode with the start/stop button. With relay circuit board connector B (14P) and connector C (10P) disconnected, measure voltage between relay circuit board connector C (10P) No. 7, PNK, and body ground. If there is battery voltage, the IG1 WIPER wire is OK. If there is not battery voltage, repair an open or high resistance in that wire.
Check the relay board ground
Turn the ignition back to LOCK (0), or select OFF mode. With relay circuit board connectors B (14P) and C (10P) still disconnected, check continuity between relay circuit board connector B (14P) No. 3, BLK, and body ground. If there is continuity, the ground wire is OK. If there is no continuity, repair an open or high resistance in the ground wire or a poor ground at G301.
Test the relay circuit board
With the feeds and ground checked, test the relay circuit board. If the relay circuit board is OK, continue into the control-line and motor-circuit continuity checks. If the relay circuit board is not OK, replace the relay circuit board.
Check the FR WIPER INT RLY CL- line
Disconnect under-dash fuse/relay box connector E (36P). With the ignition in LOCK (0) or OFF mode, under-dash connector E disconnected, and relay circuit board connectors B (14P) and C (10P) disconnected, jumper relay circuit board connector B (14P) No. 12, PUR, to body ground. Check continuity between under-dash fuse/relay box connector E (36P) No. 22, PUR, and body ground. If there is continuity, the FR WIPER INT RLY CL- wire is OK. If there is no continuity, repair an open or high resistance in the wire.
Check the WIPER HI/LO RLY CL- line
Next, keep the connectors disconnected and jumper relay circuit board connector B (14P) No. 4, LT BLU, to body ground. Check continuity between under-dash fuse/relay box connector E (36P) No. 29, LT BLU, and body ground. If there is continuity, the WIPER HI/LO RLY CL- wire is OK. If there is no continuity, repair an open or high resistance in the wire.
Check the wiper high-speed motor circuit
Now disconnect the windshield wiper motor 4P connector. With OFF mode selected, under-dash connector E disconnected, relay circuit board connectors B and C disconnected, and the wiper motor connector disconnected, check continuity between relay circuit board connector B (14P) No. 2, GRY, and windshield wiper motor 4P connector No. 3, GRY. If there is continuity, the FR WIPER HI wire is OK. If there is no continuity, repair an open or high resistance in the wire.
Check the wiper low-speed motor circuit
Then check the low-speed circuit. With the same disconnected setup, check continuity between relay circuit board connector B (14P) No. 11, ORN, and windshield wiper motor 4P connector No. 1, ORN. If there is continuity, the FR WIPER LO wire is OK. If there is no continuity, repair an open or high resistance in the wire.
Final component decision in this path
After the feed, ground, relay-board, control-line, and motor-circuit checks pass, perform the windshield wiper motor test again. If the wiper motor runs and pulses normally, the fault is in the MICU; replace the under-dash fuse/relay box. If the wiper motor does not run and pulse normally, replace the windshield wiper motor.
Closing takeaway
The clean way through B1077 is to split the diagnosis early: if the motor works, prove the park-signal side; if it does not, prove the fuses, feeds, ground, relay board, control lines, and motor circuits before making the final call. Take your time with connector identification and continuity setup, because this code depends on the MICU seeing the correct wiper park behavior. For more diagnostic training, visit stepdiagnostics.com.
Final check
B1077 is often best approached by first proving whether the wiper motor runs, then following the circuit path in order without jumping to a component call.
For more guided automotive diagnostics, visit STEP Diagnostics.
