DTC B1127: Driver's Door Key Cylinder Switch Signal Error
NOTE:
If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see
TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
).
- Clear the DTCs with the HDS.
- Turn the ignition switch OFF, and then back ON (II).
- Insert the ignition key into the driver's door key cylinder switch, and turn the key in LOCK and UNLOCK positions ten times.
- Check for DTCs with the HDS.
Is DTC B1127 indicated?
YES -Go to step 5.
NO -Intermittent failure. The driver's door key cylinder switch system is OK at this time.
- With the driver's door key cylinder in the neutral position, select KEYLESS with the HDS, and enter the DATA LIST.
- Check the ON/OFF information of the DRIVER'S DOOR KEY CYLINDER SWITCH (LOCK) and DRIVER'S DOOR KEY CYLINDER SWITCH (UNLOCK) in the DATA LIST.
Are both information indicators OFF?
YES -Go to step 12.
NO -Go to step 7.
- Disconnect the driver's door lock actuator 10P connector.
- Check the ON/OFF information of the DRIVER'S DOOR KEY CYLINDER SWITCH (LOCK) and DRIVER'S DOOR KEY CYLINDER SWITCH (UNLOCK) in the DATA LIST.
Are both information indicators OFF?
YES -Faulty driver's door key cylinder switch; replace the driver's door lock actuator.
NO -Go to step 9.
- Turn the ignition switch OFF.
- Disconnect the under-dash fuse/relay box connector T (34P).
- Check for continuity between the No. 31 (UNLOCK) and No. 32 (LOCK) terminals of the under-dash fuse/relay box connector T (34P) and body ground.Fig 1: Checking Continuity Between 31 (UNLOCK) And 32 (LOCK) Terminals Of Under-Dash Fuse/Relay Box Connector T (34P) And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Faulty MICU, replace the under-dash fuse/relay box.
NO -Go to step 12.
- Turn the ignition switch OFF.
- Disconnect the driver's door lock actuator 10P connector.
- Disconnect under-dash fuse/relay box connector T (34P).
- Check for continuity between the No. 31 (UNLOCK) and No. 32 (LOCK) terminals of the under-dash fuse/relay box connector T (34P).Fig 2: Checking Continuity Between 31 (UNLOCK) And 32 (LOCK) Terminals Of Under-Dash Fuse/Relay Box Connector T (34P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short in the wire between the LOCK and UNLOCK wires.
NO -Substitute a known-good MICU, and recheck. If the symptom/indication goes away, replace the original MICU, if not, replace the driver's door lock actuator.