LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 1999 >> Mustang Base, 2D Convertible, Standard >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Module Communications Network >> Diagnostic Trouble Code (DTC) Definitions
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Trouble Code (DTC) Definitions

ANTI-LOCK BRAKE SYSTEM MODULE DTC INDEX

DTC Description Perform Test
B1318 Battery Voltage Low (1)
B1342 ECU Defective (2)
B1484 Brake Pedal Input Circuit Open (1)
B1596 Repair Continuous DTCs (3)
C1095 ABS Hydraulic Pump Motor Circuit Failure (1)
C1145 Right Front ABS Sensor Input Circuit Failure (1)
C1155 Left Front ABS Sensor Input Circuit Failure (1)
C1165 Right Rear ABS Sensor Input Circuit Failure (1)
C1175 Left Rear ABS Sensor Input Circuit Failure (1)
C1222 Anti-Lock Brake Sensor Mismatch (1)
C1233 Left Front ABS Sensor Input Signal Missing (1)
C1234 Right Front ABS Sensor Input Signal Missing (1)
C1235 Right Rear ABS Sensor Input Signal Missing (1)
C1236 Left Rear ABS Sensor Input Signal Missing (1)
C1266 ABS Valve Power Relay Circuit Failure (4)
C1805 Mismatched PCM And/Or ABS Module (5)
U1009 Invalid/Missing Data For Engine Torque (6)
U1027 Invalid/Missing Data For Engine RPM (6)
U1059 Invalid/Missing Data For Transmission Range Switch (6)
U1083 Invalid/Missing Data For Engine System (6)
U1262 SCP Bus Communication Fault (7)
(1) Repair Anti-Lock Brake System (ABS). See appropriate ANTI-LOCK article in BRAKES.
(2) Using NGS tester, retrieve and document all continuous. Perform Anti-Lock Brake System (ABS) module self-test. If DTC B1342 is retrieved again, replace ABS module.
(3) Repair all DTC retrieved.
(4) Replace ABS module.
(5) Using NGS tester, retrieve and document all continuous. Perform Anti-Lock Brake System (ABS) module self-test. If DTC C1805 is retrieved again, replace PCM and/or ABS module as necessary.
(6) Cause by Powertrain Control Module (PCM). Using NGS tester, perform PCM self-test. For PCM DTC testing procedures, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
(7) Perform TEST G: NO MODULE/NETWORK COMMUNICATION - BUS LINK  under SYSTEM TESTS.
GENERIC ELECTRONIC MODULE DTC INDEX

DTC Description Perform Test
B1217 Horn Relay Coil Circuit Failure (1)
B1218 Horn Relay Coil Circuit Short To Voltage (1)
B1312 Headlight Input Circuit Short To Voltage (2)
B1317 Battery Voltage High (3)
B1318 Battery Voltage Low (3)
B1322 Driver's Door Ajar Circuit Short To Ground (4)
B1330 Passenger's Door Ajar Circuit Short To Ground (4)
B1334 Trunk Lid/Rear Door Ajar Circuit Short To Ground (4)
B1340 Chime Input Request Circuit Short To Ground (5)
B1342 ECU Defective (6)
B1353 Key-In-Ignition Circuit Open (5)
B1359 Ignition Switch RUN/ACC Circuit Failure (1)
B1396 Power Door Lock Circuit Short To Voltage (4)
B1397 Power Door Unlock Circuit Short To Voltage (4)
B1405 Driver's Power Window Down Circuit Short To Voltage (7)
B1408 Driver's Power Window Up Circuit Short To Voltage (7)
B1410 Driver's Power Window Motor Circuit Short To Voltage (7)
B1426 Seat Belt Switch Circuit Short To Voltage (5)
B1428 Seat Belt Indicator Circuit Failure (5)
B1431 On/Off Relay Circuit Failure (8)
B1432 On/Off Relay Circuit Short To Power (8)
B1434 High/Low Relay Coil Circuit Failure (8)
B1436 High/Low Relay Coil Circuit Short To Power (8)
B1438 Wiper Switch Circuit Failure (8)
B1441 Wiper Switch Circuit Short To Ground (8)
B1446 Park Sense Circuit Failure (8)
B1448 Park Sense Circuit Short To Power (8)
B1450 Wash/Delay Switch Circuit Failure (8)
B1453 Wash/Delay Switch Circuit Short To Ground (8)
B1458 Washer Pump Relay Circuit Failure (8)
B1460 Washer Pump Relay Coil Circuit Short To Power (8)
B1462 Seat Belt Switch Circuit Failure (5)
B1466 High & Low Speeds Not Switching (8)
B1473 Motor Low Speed Circuit Failure (8)
B1476 Motor High Speed Circuit Failure (8)
B1498 Trunk Lid Punch-Out Sensor Short To Ground (4)
B1551 Trunk Lid Release Circuit Failure (4)
B1553 Trunk Lid Release Circuit Short To Voltage (4)
B1555 Ignition RUN/START Circuit Failure (1)
B1603 Anti-Theft Indicator Circuit Failure (9)
B1605 Anti-Theft Indicator Circuit Short To Voltage (9)
B1687 Dome Light Input Circuit Short To Voltage (10)
B1833 Door Unlock Disarm Switch Circuit Short To Ground (9)
B2486 Parking Light Output Relay Circuit Failure (9)
B2488 Parking Light Output Relay Circuit Short To Voltage (9)
C1189 Brake Fluid Level Sensor Input Short To Voltage (5)
C1223 Brake Light Warning Output Circuit Failure (5)
C1225 Brake Light Warning Output Circuit Short To Voltage (5)
(1) See STEERING COLUMN SWITCHES - MUSTANG article for testing procedure.
(2) See appropriate wiring diagram in HEADLIGHT SYSTEMS article.
(3) Check charging system. See appropriate GENERATORS article in STARTING & CHARGING SYSTEMS. If charging system is okay, check power and ground circuits to GEM. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
(4) See appropriate wiring diagram in REMOTE KEYLESS ENTRY SYSTEMS and/or POWER DOOR LOCK & REMOTE TRUNK RELEASE article.
(5) See INSTRUMENT PANELS - MUSTANG article for testing procedure.
(6) Using NGS tester, retrieve and document all continuous. Perform Generic Electronic Module (GEM) self-test. If DTC B1342 is retrieved again, replace GEM.
(7) See POWER WINDOWS - MUSTANG article for testing procedure.
(8) See WIPER/WASHER SYSTEMS - MUSTANG article for testing procedure.
(9) See PASSIVE ANTI-THEFT SYSTEMS - MUSTANG article for testing procedure.
(10) See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article.
INSTRUMENT CLUSTER DTC INDEX

Scan Tool DTC Dealer Test Mode DTC Description Perform Test
B1202 9202 Fuel Sender Circuit Open (1)
B1204 9204 Fuel Sender Short To Ground (1)
B1213 9213 Anti-Theft Number Of Programmed Ignition Keys Is Below Minimum (2)
B1232 Or B2103 A103 Or 9232 Defective Transceiver (2)
B1317 9317 Battery Voltage High (3)
B1318 9318 Battery Voltage Low (3)
B1342 9342 ECU Defective (4)
B1356 9356 Ignition Run Circuit Open (5)
B1364 9364 Ignition Start Circuit Open (5)
B1600 9600 PATS Ignition Key Transponder Signal Not Received (2)
B1601 9601 PATS Received Incorrect Key-Code From Transponder (2)
B1602 9602 PATS Received Invalid Key-Code Format From Transponder (2)
B1681 9681 PATS Transceiver Signal Not Received (2)
B2139 A139 Security Identification Does Not Match Between Instrument Cluster & PCM (2)
B2141 A141 NVM Configuration Failure (2)
B2143 A143 NVM Memory Failure (6)
C1284 5284 Oil Pressure Switch Failure (1)
U1027 D027 Invalid/Missing Data For Engine RPM (7)
U1041 D041 Invalid/Missing Data For Vehicle Speed (7)
U1043 D043 Invalid/Missing Data For Traction Control (8)
U1073 D073 Invalid/Missing Data For Engine Coolant (7)
U1123 D123 Invalid/Missing Data For Odometer (7)
U1147 D147 SCP Invalid/Missing Data For Vehicle Security (2)
U1262 D262 SCP Bus Communications Fault (9)
(1) See INSTRUMENT PANELS - MUSTANG article for testing procedure.
(2) See PASSIVE ANTI-THEFT SYSTEMS - MUSTANG article for testing procedure.
(3) Check charging system. See appropriate GENERATORS article in STARTING & CHARGING SYSTEMS. If charging system is okay, check power and ground circuits to instrument cluster. See appropriate wiring diagram in POWER DISTRIBUTION article in WIRING DIAGRAMS.
(4) Using NGS tester, retrieve and document all continuous. Perform instrument cluster self-test. If DTC B1342 is retrieved again, replace instrument cluster.
(5) See STEERING COLUMN SWITCHES - MUSTANG article for testing procedure.
(6) Replace instrument cluster.
(7) Cause by PCM. Repair communication circuit between instrument cluster and PCM.
(8) Cause by ABS module. Repair communication circuit between instrument cluster and ABS module.
(9) Service all other DTCs first. After all other DTC concerns have been repaired, perform TEST G: NO MODULE/NETWORK COMMUNICATION - BUS LINK  under SYSTEM TESTS.
RESTRAINTS CONTROL MODULE DTC INDEX

DTC (1) Description Perform Test
B1342 ECU Defective (2)
B1231 RCM Crash Data Memory Full (2)
B1921 RCM Bracket Ground Resistance High (2)
C1414 Incorrect Vehicle Identification Code (2)
B1887 Driver's Side Air Bag Circuit Short To Ground (2)
B1916 Driver's Side Air Bag Circuit Short To Voltage (2)
B1888 Passenger's Side Air Circuit Bag Short To Ground (2)
B1925 Passenger's Side Air Bag Circuit Short To Voltage (2)
B1932 Driver's Side Air Bag Circuit Resistance High (2)
B1933 Passenger's Side Air Bag Circuit Resistance High (2)
B1934 Driver's Side Air Bag Circuit Resistance Low (2)
B1935 Passenger's Side Air Bag Circuit Resistance Low (2)
B1892 Air Bag Tone Warning Indicator Circuit Short To Ground Or Open (2)
B1891 Air Bag Tone Warning Indicator Circuit Short To Voltage (2)
B1869 Air Bag Indicator Inoperative (2)
B1870 Air Bag Indicator Short To Voltage (2)
(1) DTCs are listed in order of importance. Repair DTCs in order listed.
(2) Repair supplemental restraint system as necessary. See DIAGNOSIS & TESTING article in appropriate lemon-25(R) AIR BAG SERVICE & REPAIR MANUAL, DOMESTIC & IMPORTED MODELS.
scientia non olet · About LEMON Manuals