ABS Diagnostic Procedure

[yenadar]

From the factory workshop manual:
Note: The DTC items should be available through a normal OBD2 code reader as "C" codes, however, if you do not have a code reader, this will let you retrieve the ABS codes anyway.

2005 - Miata - Workshop Manual - Brakes
ABS ON-BOARD DIAGNOSIS

On-Board Diagnostic (OBD) Test Description

• The OBD test inspects the integrity and function of the ABS and outputs the results when requested by the specific tests.
• On-board diagnostic test also:
• Provides a quick inspection of the ABS.
  
• Is usually performed at the start of each diagnostic procedure.
• Provides verification after repairs to ensure that no other faults occurred during service.
• The OBD test is divided into 3 tests:
• Read/clear diagnostic results, PID monitor and record and active command modes.
• Read/clear diagnostic results
• This function allows you to read or clear DTCs in the ABS HU/CM memory.
• PID/data monitor and record
• This function allows you to access certain data values, input signals, calculated values, and system status information.
• Active command modes
• This function allows you to control devices through the SST (WDS or equivalent).

Reading DTCs Procedure

Using SST (WDS or equivalent)
1. Connect WDS or equivalent to the vehicle DLC‐2 16‐pin connector located on the left side of the steering column.
2. Retrieve DTC with WDS or equivalent.

Without using SST (WDS or equivalent)
CAUTION:
Connecting to the wrong DTS terminal may cause a malfunction. Carefully connect only to the specified terminal.
1. Connect the TBS terminal at DLC to body ground using a jumper wire.
2. Turn the ignition key to ON (engine OFF).
3. After the ABS warning light illuminates for 3 seconds, the ABS warning light indicates DTCs.
4. After completion of repairs, clear DTCs.



Clearing DTCs Procedures

Using SST (WDS or equivalent)
After repairs have been made, perform the Reading DTCs Procedure.
1. Erase DTC with WDS or equivalent.

Without using SST (WDS or equivalent)
CAUTION:
Connecting to the wrong DTS terminal may cause a malfunction. Carefully connect only to the specified terminal.
1. Connect the TBS terminal at the DLC to body ground using a jumper wire.
2. Turn the ignition key to ON (engine OFF).
3. Output all stored DTCs.
4. After verifying that the first code is repeated, depress the brake pedal 10 times or more at intervals of less than 1 seconds.
5. Turn the ignition key to OFF and disconnect the jumper wire.
NOTE:
DTCs cannot be cleared if the following occur:
a. If intervals of depressing the brake pedal exceed 1 seconds.
b. The brake switch has failed.
PID/Data Monitor and Record Procedure
1. Connect WDS or equivalent to the vehicle DLC-2 16-pin connector located on the left side of the steering column.
2. Access and monitor PIDs with WDS or equivalent.
Active Command Modes Procedure
1. Connect WDS or equivalent to the vehicle DLC-2 16-pin connector located on the left side of the steering column.
2. Turn the ignition key to ON (Engine OFF) or start engine.
3. Activate active command modes with WDS or equivalent.

[yenadar]

ABS Warning Light Flash Pattern:
a: 3 seconds of the light being on, followed by 2 seconds off indicates that it is in DTC mode
b: Long flashes of 1.2s each are the "tens" place
c: Short flashes of 0.4s each are the "ones" place.
d: There is a 1.6s period of no light between the "tens" and the "ones"
e: There is a 4 second period of the light off before it moves to the next code or repeats.

So for example: 4 long flashes and 2 short flashes = "code 42" (the answer to the universe, life, and everything ... including the Left front speed sensor conherency fault)

[yenadar]

DTC List:

Code:

OBD2 Code - ABS code - Definition - System Component
B1318 - 63 - BATTERY VOLTAGE LOW - ABS HU/CM power supply
B1342 - 61 - PCM DEFECTIVE - ABS HU/CM (CM)
B1484 - 05 - BRAKE PEDAL INPUT-OPEN CIRCUIT - Brake switch harness
C1095 - 54 - HYDRAULIC PUMP MOTOR‐CKT FAILURE - ABS motor, motor relay
C1096 - 53 - HYDRAULIC PUMP MOTOR OPEN CKT - ABS motor, motor relay
C1145 - 11 - RF SPEED SENSOR INPUT CKT FAILURE - Right front ABS wheelspeed sensor
C1148 - 41 - RF SPEED SENSOR COHERENCY FAULT - Right front ABS wheelspeed sensor/sensor rotor
C1155 - 12 - LF SPEED SENSOR INPUT CKT FAILURE - Left front ABS wheel‐speed sensor
C1158 - 42 - LF SPEED SENSOR COHERENCY FAULT - Left front ABS wheel‐speed sensor/sensor rotor
C1165 - 13 - RR SPEED SENSOR INPUT CKT FAILURE - Right rear ABS wheelspeed sensor
C1168 - 43 - RR SPEED SENSOR COHERENCY FAULT - Right rear ABS wheelspeed sensor/sensor rotor
C1175 - 14 - LR SPEED SENSOR INPUT CKT FAILURE - Left rear wheel‐speed sensor
C1178 - 44 - LR SPEED SENSOR COHERENCY FAULT - Left rear ABS wheel‐speed sensor/sensor rotor
C1186 - 51 - ABS POWER RELAYOUTPUT OPEN CKT - Valve relay
C1194 - 24 - LF DUMP VALVE COILCKT FAILURE - Left front ABS pressure reduction solenoid valve
C1198 - 25 - LF ISOL VALVE COILCKT FAILURE - Left front ABS pressure retention solenoid valve
C1210 - 22 - RF DUMP VALVE COILCKT FAILURE - Right front ABS pressure reduction solenoid valve
C1214 - 23 - RF ISOL VALVE COILCKT FAILURE - Right front ABS pressure retention solenoid valve
C1222 - 15 - WHEEL SPEED MISSMATCH - ABS wheelspeed sensor
C1202 - 26 - RR DUMP VALVE COILCKT FAILURE - Right rear ABS pressure reduction solenoid valve
C1206 - 27 - RR ISOL VALVE COILCKT FAILURE - Right rear ABS pressure retention solenoid valve
C1266 - 52 - ABS POWER RELAY VALVE‐CKT FAILURE - Valve relay