DTC Troubleshooting Index
NOTE:
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
MICU - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1000 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1001 | MICU internal (CPU) error | Internal Error |
| B1002 | MICU internal (EEPROM) error | Internal Error |
| B1005 | MICU lost communication with relay control module (RM message) | Loss of Communication |
| B1007 | MICU lost communication with combination switch control unit (HLSW message) | Loss of Communication |
| 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 |
| B1013 | MICU lost communication with driver's MPCS unit (ASLOCKSW message) | Loss of Communication |
| B1014 | MICU lost communication with driver's MPCS unit (DOORSW message) | Loss of Communication |
| B1015 | MICU lost communication with driver's MPCS unit (DRLOCKSW message) | Loss of Communication |
| B1016 | MICU lost communication with keyless access control unit (PANIC message) | Loss of Communication |
| B1032 | MICU Collision detection system (CDS) input error | Signal Error |
| B1575 | Automatic lighting sensor circuit malfunction | Signal Error |
Relay Control Module
RELAY CONTROL MODULE - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1050 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1055 | Relay control module lost communication with MICU (MICU message) | Loss of Communication |
| B1056 | Relay control module lost communication with MICU (ALARM message) | Loss of Communication |
| B1060 | Relay control module lost communication with gauge control module (VSP/NE message) | Loss of Communication |
| B1061 | Relay control module lost communication with gauge control module (A/T message) | Loss of Communication |
| B1062 | Relay control module lost communication with combination switch control unit (HLSW message) | Loss of Communication |
| B1063 | Relay control module lost communication with combination switch control unit (WIPSW message) | Loss of Communication |
| B1064 | Relay control module lost communication with driver's MPCS unit (DOORSW message) | Loss of Communication |
| B1065 | Relay control module lost communication with driver's MPCS unit (DRLOCKSW message) | Loss of Communication |
| B1066 | Relay control module lost communication with keyless access control unit (PANIC message) | Loss of Communication |
| B1075 | Headlight signal error | Signal Error |
| B1076 | Windshield wiper signal error | Signal Error |
| B1077 | Windshield wiper (As) signal error | Signal Error |
| B1078 | Daytime running lights malfunction (Canada) | Signal Error |
| B1079 | Daytime running lights malfunction (USA) | Signal Error |
| B1080 | Power supply circuit (IG1 line) input error for relay control module and MICU | Signal Error |
Driver's MPCS Unit (Rear Power Window section)
DRIVER'S MPCS UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1132 | Left rear power window motor pulse A error | Signal Error |
| B1133 | Left rear power window motor pulse B error | Signal Error |
| B1134 | Right rear power window motor pulse A error | Signal Error |
| B1135 | Right rear power window motor pulse B error | Signal Error |
| B1136 | Right rear power window switch internal error | Signal Error |
| B1147 | Left rear power window position detect circuit error | Signal Error |
| B1148 | Left rear power window switch internal error | Signal Error |
| B1149 | Right rear power window position detect circuit error | Signal Error |
Gauge Control Module
GAUGE CONTROL MODULE - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1150 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1152 | Gauge control module internal (EEPROM) error | Internal Error |
| B1155 | Gauge control module lost communication with combination switch control unit (HLSW message) | Loss of Communication |
| B1156 | Gauge control module lost communication with combination switch control unit (WIPSW message) | Loss of Communication |
| B1157 | Gauge control module lost communication with MICU | Loss of Communication |
| B1158 | Gauge control module lost communication with relay control module (RM message) | Loss of Communication |
| B1161 | Gauge control module lost communication with keyless access control unit (REMOTE ID message) | Loss of Communication |
| B1166 | Gauge control module lost communication with adaptive front lighting control unit (AFS message) | Loss of Communication |
| B1168 | Gauge control module lost communication with PCM (ENG message) | Loss of Communication |
| B1169 | Gauge control module lost communication with PCM (A/T messages) | Loss of Communication |
| B1170 | Gauge control module lost communication with VSA modulator-control unit (VSA message) | Loss of Communication |
| B1171 | Gauge control module lost communication with adaptive cruise control (ACC) unit (ACC message) | Loss of Communication |
| B1173 | Gauge control module lost communication with TPMS control unit (TPMS 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 | Battery Voltage |
| B1178 | F-CAN communication line error | Loss of Communication |
| B1180 | Gauge control module lost communication with MICU (AUTOLT message) | Loss of Communication |
| B1181 | Gauge control module lost communication with driver's MPCS unit (DOORSW message) | Loss of Communication |
| B1182 | Gauge control module lost communication with driver's MPCS unit (DRLOCKSW message) | Loss of Communication |
Climate Control Unit
CLIMATE CONTROL UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC type |
|---|---|---|
| B1200 | Communication bus line (BUS-OFF) | Loss of Communication |
| B1202 | Climate control unit internal error | Loss of Communication |
| B1205 | Climate control unit lost communication with gauge control module (VSP/NE massage) | Loss of Communication |
| B1206 | Climate control unit lost communication with gauge control (ECT message) | Loss of Communication |
| B1207 | Climate control unit lost communication with gauge control module (ILLUMI message) | Loss of Communication |
| B1208 | Climate control unit lost communication with keyless access control unit (REMOTE ID message) | Loss of Communication |
| B1225 | An open in the in-car temperature sensor circuit | Signal Error |
| B1226 | A short in the in-car temperature sensor circuit | Signal Error |
| B1227 | An open in the outside air temperature sensor circuit | Signal Error |
| B1228 | A short in the outside air temperature sensor circuit | Signal Error |
| B1229 | An open in the sunlight sensor circuit | Signal Error |
| B1230 | A short in the sunlight sensor circuit | Signal Error |
| B1231 | An open in the evaporator temperature sensor circuit | Signal Error |
| B1232 | A short in the evaporator temperature sensor circuit | Signal Error |
| B1235 | A problem in the driver's air mix control linkage, door, or motor | Signal Error |
| B1238 | A problem in the passenger's air mix control linkage, door, or motor | Signal Error |
| B1240 | A problem in the mode control linkage, doors, or motor | Signal Error |
| B1241 | A problem in the blower motor circuit | Signal Error |
| B2975 | An open in the driver's vent air temperature sensor circuit | Signal Error |
| B2976 | A short in the driver's vent air temperature sensor circuit | Signal Error |
| B2977 | An open in the passenger's vent air temperature sensor circuit | Signal Error |
| B2978 | A short in the passenger's vent air temperature sensor circuit | Signal Error |
| B2979 | An open in the A/C pressure sensor circuit | Signal Error |
| B2980 | A short in the A/C pressure sensor circuit | Signal Error |
| B2981 | Climate control unit lost communication with navigation unit | Loss of Communication |
| B2982 | Climate control unit lost communication with each control motor | Loss of Communication |
| B2983 | A problem in the recirculation control linkage, doors, or motor | Signal Error |
| B2984 | A problem in the driver's cool vent control linkage, doors, or motor | Signal Error |
| B2985 | A problem in the passenger's cool vent control linkage, door, or motor | Signal Error |
| B2987 | A problem in the rear vent control linkage, doors, or motor | Signal Error |
| B2991 | Climate control unit lost communication with audio unit | Loss of Communication |
Combination Switch Control Unit
COMBINATION SWITCH CONTROL UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1250 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1255 | Combination switch control unit lost communication with MICU | Loss of Communication |
| B1275 | Combination light switch OFF position circuit malfunction | Signal Error |
| B1276 | Combination light switch parking (SMALL) position circuit malfunction | Signal Error |
| B1277 | Headlight switch AUTO position circuit malfunction | Signal Error |
| B1278 | Headlight switch ON position circuit malfunction | Signal Error- |
| B1279 | Headlight switch DIMMER position circuit malfunction | Signal Error |
| B1280 | Turn signal switch circuit malfunction | Signal Error |
| B1281 | Windshield wiper switch MIST position circuit malfunction | Signal Error |
| B1282 | Windshield wiper switch INT (AUTO) position circuit malfunction | Signal Error |
| B1283 | Windshield wiper switch LOW position circuit malfunction | Signal Error |
| B1284 | Windshield wiper switch HIGH position circuit malfunction | Signal Error |
OnStar Control Unit ('05-06 models)
ONSTAR CONTROL UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1400 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1401 | OnStar control unit internal (CPU) error | Internal error |
| B1402 | OnStar control unit internal (EEPROM) error | Internal error |
| B1403 | GPS receiver error | Signal Error |
| B1404 | Telephone module error | Signal Error |
| B1405 | OnStar control unit lost communication with driver's MPCS unit (DOORSW message) | Loss of communication |
| B1406 | OnStar control unit lost communication with driver's MPCS unit (DRLOCKSW message) | Loss of communication |
| B1407 | OnStar control unit lost communication with driver's MPCS unit (ASLOCKSW message) | Loss of communication |
| B1408 | OnStar control unit lost communication with gauge control module (VSP/NE message) | Loss of communication |
| B1425 | OnStar control unit lost communication with SRS unit (CDS message) | Loss of communication |
| B1426 | OnStar switches circuit malfunction | Signal Error |
| B1427 | Microphone circuit malfunction | Signal Error |
| B1428 | GPS antenna circuit malfunction | Signal Error |
| B1433 | Cellular phone antenna circuit malfunction | Signal Error |
Keyless Access Control Unit
KEYLESS ACCESS CONTROL UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1600 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1601 | Keyless access control unit internal (CPU) error | Internal Error |
| B1602 | Keyless access control unit internal (EEPROM) error | Internal Error |
| B1605 | Keyless access control unit lost communication with MICU (MICU message) | Loss of Communication |
| B1610 | Keyless access control unit lost communication with gauge control module (VSP/NE message) | Loss of Communication |
| B1613 | Keyless access control unit lost communication with driver's MPCS unit (DOORSW message) | Loss of Communication |
| B1614 | Keyless access control unit lost communication with driver's MPCS unit (DRLOCKSW message) | Loss of Communication |
| B1615 | Keyless access control unit lost communication with driver's MPCS unit (ASLOCKSW message) | Loss of Communication |
| B1626 | Ignition switch control unit no response | Signal Error |
| B1627 | RF Unit 1 not connected | Signal Error |
| B1628 | RF Unit 2 not connected | Signal Error |
| B1640 | RF Unit 1 circuit malfunction | Signal Error |
| B1641 | RF Unit 2 circuit malfunction | Signal Error |
| B1645 | Driver's door LF antenna circuit short | Signal Error |
| B1646 | Driver's door LF antenna circuit open | Signal Error |
| B1647 | Passenger's door LF antenna circuit short | Signal Error |
| B1648 | Passenger's door LF antenna circuit open | Signal Error |
| B1657 | Rear bumper LF antenna circuit short | Signal Error |
| B1658 | Rear bumper LF antenna circuit open | Signal Error |
| B1659 | Front interior LF antenna circuit short | Signal Error |
| B1660 | Front interior LF antenna circuit open | Signal Error |
| B1663 | Rear interior LF antenna circuit short | Signal Error |
| B1664 | Rear interior LF antenna circuit open | Signal Error |
| B1667 | Rear shelf LF antenna circuit short | Signal Error |
| B1668 | Rear shelf LF antenna circuit open | Signal Error |
| B1671 | Ignition switch control unit (Key SW) circuit open | Signal Error |
| B1672 | Ignition switch control unit (KNOB SW) circuit short | Signal Error |
| B1673 | Ignition switch control unit (KNOB SW) circuit open | Signal Error |
| B1674 | Ignition switch control unit (ROTATE SW) circuit short | Signal Error |
| B1675 | Ignition switch control unit (ROTATE SW) circuit open | Signal Error |
HandsFreeLink Control Unit
HANDSFREELINK CONTROL UNIT - DTC TROUBLESHOOTING CHART
| 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 or HFL-voice control switch (HFL talk/ HFL back buttons) circuit open/short | Signal Error |
| B1780 | HFL-voice control switch (HFL talk/HFL back buttons) circuit short | Signal Error |
| B1792 | HandsFreeLink control unit internal error | Internal Error |
Power Seat Control Unit
POWER SEAT CONTROL UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B1800 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B1802 | Power seat control unit internal (EEPROM) error | Loss of Communication |
| B1805 | Power seat control unit lost communication with gauge control module (VSP/NE message) | Loss of Communication |
| B1806 | Power seat control unit lost communication with MICU | Loss of Communication |
| B1808 | Power seat control unit lost communication with gauge control module (A/T message) | Loss of Communication |
| B1810 | Power seat control unit lost communication with MICU (MIRRORSW message) | Loss of Communication |
| B1811 | Power seat control unit lost communication with driver's MPCS unit (DOORSW message) | Loss of Communication |
| B1812 | Power seat control unit lost communication with driver's MPCS unit (MEMSW message) | Loss of Communication |
| B1825 | Power seat slide motor pulse error | Signal Error |
| B1826 | Power seat front up-down motor pulse error | Signal Error |
| B1827 | Power seat rear up-down motor pulse error | Signal Error |
| B1828 | Power seat recline motor pulse error | Signal Error |
| B1829 | A/T P signal and VSS signal mismatch | Signal Error |
| B1835 | Tilt/telescopic switch signal input error | Signal Error |
| B1836 | Power seat position sensor circuit short | Signal Error |
| B1837 | Driving position memory recall timeout | Signal Error |
| B1840 | Tilt motor pulse error | Signal Error |
| B1841 | Telescopic motor pulse error | Signal Error |
| B1842 | Power tilt/telescopic position sensor power supply circuit (SVCC line) short | Signal Error |
| B1843 | Power seat control unit lost communication with power tilt/telescopic steering control unit (UART line) | Loss of Communication |
| B1844 | Power seat slide switch circuit malfunction | Signal Error |
| B1845 | Power seat recline switch circuit malfunction | Signal Error |
| B1846 | Power seat front up-down switch circuit malfunction | Signal Error |
| B1847 | Power seat rear up-down switch circuit malfunction | Signal Error |
| B1848 | Rear headrest switch signal error | Signal Error |
Adaptive Front Lighting Control Unit
ADAPTIVE FRONT LIGHTING CONTROL UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC Type |
|---|---|---|
| B2100 | Communication bus line error (BUS-OFF) | Signal Error |
| B2105 | AFS control unit lost communication with gauge control module (STEERING message) | Loss of Communication |
| B2106 | AFS control unit lost communication with gauge control module (A/T message) | Loss of Communication |
| B2107 | AFS control unit lost communication with MICU (MICU message) | Loss of Communication |
| B2108 | AFS control unit lost communication with combination switch control unit (HLSW message) | Loss of Communication |
| B2125 | Steering angle sensor signal error | Signal Error |
| B2126 | Steering angle sensor Z pulse line or supply line open | Signal Error |
| B2127 | Steering angle sensor malfunction | Signal Error |
| B2128 | Steering angle sensor signal error | Signal Error |
| B2129 | Steering angle sensor circuit malfunction | Signal Error |
| B2130 | A short in the steering angle sensor Z pulse line | Signal Error |
| B2131 | Steering angle sensor MAX error | Signal Error |
| B2132 | Steering angle sensor learning error | Signal Error |
| B2134 | Wheel speed (RLP, RRP line) circuit open | Signal Error |
| B2135 | A/T reverse signal error | Signal Error |
| B2136 | Left AFS gearbox motor signal error | Signal Error |
| B2137 | Right AFS gearbox motor signal error | Signal Error |
| B2139 | Headlight leveling motor power supply circuit error | Signal Error |
| B2140 | Headlight leveling motor signal circuit error | Signal Error |
| B2141 | Suspension stroke sensor output error | Signal Error |
| B2142 | AFS control unit sub CPU communication error | Internal Error |
| B2143 | AFS control unit sub CPU memory error | Internal Error |
| B2144 | AFS control unit sub CPU EEPROM error | Internal Error |
| B2145 | Left AFS gearbox motor swing error | Signal Error |
| B2146 | Right AFS gearbox motor swing error | Signal Error |
Driver's MPCS Unit
DRIVER'S MPCS UNIT - DTC TROUBLESHOOTING CHART
| DTC | Description | DTC type |
|---|---|---|
| B2150 | Communication bus line error (BUS-OFF) | Loss of Communication |
| B2152 | Driver's MPCS unit internal (EEPROM) error | Internal Error |
| B2155 | Driver's MPCS unit lost communication with MICU (MICU message) | Loss of Communication |
| B2156 | Driver's MPCS unit lost communication with MICU (MIRRORSW message) | Loss of Communication |
| B2157 | Driver's MPCS unit lost communication with gauge control module (ILLUMI message) | Loss of Communication |
| B2159 | Driver's MPCS unit lost communication with keyless access control unit (REMOTE message) | Loss of Communication |
| B2160 | Driver's MPCS unit lost communication with gauge control module (VSP/NE message) | Loss of Communication |
| B2175 | Driver's power window motor pulse A error | Signal Error |
| B2176 | Driver's power window motor pulse B error | Signal Error |
| B2177 | Front passenger's power window motor pulse A error | Signal Error |
| B2178 | Front passenger's power window motor pulse B error | Signal Error |
| B2179 | Driver's door key cylinder switch LOCK/UNLOCK signal error | Signal Error |
| B2180 | Driver's door lock switch LOCK/UNLOCK signal error | Signal Error |
| B2181 | Driver's door lock knob switch LOCK/UNLOCK signal error | Signal Error |
| B2182 | Left power mirror horizontal sensor signal error | Signal Error |
| B2183 | Left power mirror vertical sensor signal error | Signal Error |
| B2184 | Right power mirror horizontal sensor signal error | Signal Error |
| B2185 | Right power mirror vertical sensor signal error | Signal Error |
| B2186 | Front passenger's door lock switch LOCK/UNLOCK signal error | Signal Error |
| B2187 | Communication line (UART line) circuit short | Signal Error |
| B2188 | Communication line (UART line) circuit open | Signal Error |
| B2189 | Driver's power window position detect error | Signal Error |
| B2190 | Front passenger's power window position detect error | Signal Error |
| B2191 | Front passenger's MPCS unit internal (EEPROM) error | Internal Error |