B1127

Factory Manual References

Factory service manual diagnostic procedure for 2006 acura csx

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 ).
  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch OFF, and then back ON (II).
  3. Insert the ignition key into the driver's door key cylinder switch, and turn the key in LOCK and UNLOCK positions ten times.
  4. 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.

  5. With the driver's door key cylinder in the neutral position, select KEYLESS with the HDS, and enter the DATA LIST.
  6. 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.

  7. Disconnect the driver's door lock actuator 10P connector.
  8. 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.

  9. Turn the ignition switch OFF.
  10. Disconnect the under-dash fuse/relay box connector T (34P).
  11. 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
    G06269268Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Faulty MICU, replace the under-dash fuse/relay box.

    NO  -Go to step 12.

  12. Turn the ignition switch OFF.
  13. Disconnect the driver's door lock actuator 10P connector.
  14. Disconnect under-dash fuse/relay box connector T (34P).
  15. 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)
    G06269269Courtesy 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.

DTC Troubleshooting Index

NOTE: Check the ECM/PCM for DTCs and troubleshoot ECM/PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first, then record all DTCs, and sort them by DTC type using the DTC troubleshooting index, then troubleshoot the DTC(s) in this order.
  • Battery voltage DTCs
  • Internal error DTCs
  • Loss of communication DTCs (beginning with the lowest number first; for example, if B1008 and B1011 are retrieved, troubleshoot B1008 first).
  • Signal error DTCs

MICU 

DTC DESCRIPTION

DTC Description DTC type
B1000  Communication bus line error (BUS-OFF) Loss of communication
B1001  MICU internal error (CPU error) Internal error
B1002  MICU internal error (EEPROM error) Internal error
B1008  MICU lost communication with gauge control module (A/T message) Loss of communication
B1011  MICU lost communication with gauge control module (VSP/NE message) Loss of communication
B1026 Front passenger's door lock switch LOCK/UNLOCK signal error Signal error
B1032  MICU lost communication with the SRS unit (CDS message)
CDS (Collision detection signal) input circuit malfunction		 Signal error
B1036  IG1 line input error Signal error
B1077 Windshield wiper (As) signal error Signal error
B1078 Daytime running lights signal error (Canada) Signal error
B1127 Driver's door key cylinder switch signal error Signal error
B1128 Driver's door lock switch signal error Signal error
B1129 Driver's door lock knob switch signal error Signal error
B1275 Combination light switch OFF position circuit malfunction ('07-09 models) Signal error
B1276 Combination light switch parking (SMALL) position circuit malfunction ('07-09 models) Signal error
B1278 Headlight switch ON position circuit malfunction ('07-09 models) Signal error
B1279 Headlight switch DIMMER position circuit malfunction ('07-09 models) Signal error
B1280 Turn signal switch circuit malfunction ('07-09 models) Signal error
B1281 Windshield wiper switch MIST circuit malfunction ('07-09) models Signal error
B1282 Windshield wiper switch INT circuit malfunction ('07-09) models Signal error
B1283 Windshield wiper switch LOW circuit malfunction ('07-09) models Signal error
B1284 Windshield wiper switch HIGH circuit malfunction ('07-09) models Signal error

Gauge Control Module 

DTC DESCRIPTION

DTC Description DTC type
B1150  Communication bus line error (BUS-OFF) Loss of communication
B1152 Gauge control module internal error (EEPROM error) Internal error
B1155 Gauge control module lost communication with the MICU (Headlight switch message) Loss of communication
B1156 Gauge control module lost communication with the MICU (Wiper switch message) Loss of communication
DTC B1157 Gauge control module lost communication with the MICU (MICU message) Loss of communication
B1159 Gauge control module lost communication with the MICU (DOORSW message) Loss of communication
B1160 Gauge control module lost communication with the MICU (DRLOCKSW message) Loss of communication
B1168 Gauge control module lost communication with the ECM/PCM (Engine messages) Loss of communication
B1169 Gauge control module lost communication with the PCM (A/T message) Loss of communication
B1170 Gauge control module lost communication with ABS/VSA modulator-control unit (ABS/VSA message) Loss of communication
B1175 Fuel level sensor (Fuel gauge sending unit) circuit open Signal error
B1176 Fuel level sensor (Fuel gauge sending unit) circuit short Signal error
B1177 Battery voltage abnormal ('06 model) Battery voltage
B1178 F-CAN communication line error Loss of communication
B1183 Gauge control module lost communication with EPS control unit (EPS message) Loss of communication
B1187 Gauge control module lost communication with the SRS unit (SRS message) Loss of communication
B1188 Gauge control module lost communication with the MICU (RM message) Loss of communication

Climate Control Unit 

DTC DESCRIPTION

DTC Description DTC type
B1200  Communication bus line error (BUS-OFF) Loss of communication
B1202 Climate control unit internal error (EEPROM error) Internal error
B1205 Climate control unit lost communication with the gauge control module (VSP/NE message) Loss of communication
B1206 Climate control unit lost communication with the gauge control module (ECT message) Loss of communication
B1207 Climate control unit lost communication with the gauge control module (ILLUMI message) Loss of communication
B1220 Recirculation control motor circuit short Signal error
B1225 In-car temperature sensor circuit open Signal error
B1226 In-car temperature sensor circuit short Signal error
B1227 Outside air temperature sensor circuit open Signal error
B1228 Outside air temperature sensor circuit short Signal error
B1229 Sunlight sensor circuit open Signal error
B1230 Sunlight sensor circuit short Signal error
B1231 Evaporator temperature sensor circuit open Signal error
B1232 Evaporator temperature sensor circuit short Signal error
B1233 Air mix control motor circuit open Signal error
B1234 Air mix control motor circuit short Signal error
B1235 Air mix control motor stuck Signal error
B1239 Mode control motor circuit open or short Signal error
B1240 Mode control motor, linkage, door malfunction Signal error
B1241 Blower motor circuit malfunction Signal error
B2983 Recirculation control motor, linkage, door malfunction Signal error
B2986 Recirculation control motor circuit open Signal error

HandsFreeLink Control Unit 

DTC DESCRIPTION

DTC Description DTC type
B1750 Communication bus line error (BUS-OFF) Loss of communication
B1775 Microphone input/output short to power/open Signal error
B1776 Microphone input/output short to ground/open Signal error
B1779 HFL switch (HFL talk/HFL back buttons) circuit open/short Signal error
B1780 HFL switch (HFL talk/HFL back buttons) circuit short Signal error
B1792 HandsFreeLink control unit internal error Internal error

Immobilizer-Keyless Control Unit 

DTC DESCRIPTION

DTC Description DTC type
B1900  Communication bus line error (BUS-OFF) Loss of communication
B1905 Immobilizer-keyless control unit lost communication with the MICU (DRLOCKSW message) Loss of communication
B1906 Immobilizer-keyless control unit lost communication with the gauge control module (A/T message) Loss of communication
B1925 Ignition key switch signal error Signal error

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 ).
  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch OFF, and then back ON (II).
  3. Insert the ignition key into the driver's door key cylinder switch, and turn the key in LOCK and UNLOCK positions ten times.
  4. 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.

  5. With the driver's door key cylinder in the neutral position, select KEYLESS with the HDS, and enter the DATA LIST.
  6. 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.

  7. Disconnect the driver's door lock actuator 10P connector.
  8. 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.

  9. Turn the ignition switch OFF.
  10. Disconnect the under-dash fuse/relay box connector T (34P).
  11. 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
    G06269268Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Faulty MICU, replace the under-dash fuse/relay box.

    NO  -Go to step 12.

  12. Turn the ignition switch OFF.
  13. Disconnect the driver's door lock actuator 10P connector.
  14. Disconnect under-dash fuse/relay box connector T (34P).
  15. 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)
    G06269269Courtesy 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.

Supporting Diagrams & Locations

Reference material from the factory manual for this diagnostic procedure.

Diagram

Circuit Diagram

Diagram

Circuit Diagram

Diagram

Circuit Diagram

Diagram

Body Controller Area Network (B-CAN) and Fast Controller Area Network (F-CAN)

Diagram

Gateway Function

Diagram

Circuit Diagram

Location

Component Location Index

Location

Component Location Index

Location

Component Location Index

Location

Component Location Index

Fuse/Relay

DTC B1905: Immobilizer-Keyless Control Unit Lost Communication with MICU (DRLOCKSW Message)

Fuse/Relay

DTC B1925: Ignition Key Switch Signal Error

Fuse/Relay

Immobilizer-keyless Control Unit Input Test

Fuse/Relay

Immobilizer indicator blinks

Related Procedures

Procedure

Immobilizer-keyless Control Unit Replacement

Procedure

Delete or add multiple keys

Procedure

Immobilizer indicator blinks

Procedure

Immobilizer indicator does not go off

Procedure

General Check before Troubleshooting

Procedure

Doors automatically relock after being unlocked with the transmitter even though a door has been opened

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