ABS Fault Code Reading NA (MKI) - NB (MKII)

To check for DTC on the ABS system on MX-5 turn ignition switch to off, bridge the TBS and GND terminals in the DIAGNOSTIC socket under the bonnet, turn the igniton switch to on and count the groups of flashes on the ABS lamp. Long flashes count tens, short flashes count units. To clear DTC, allow all codes to be output (flash codes repeat) then with ignition switch still on, press and release the brake pedal 10 times at less than 1 second intervals.

Diagnostic Trouble Codes are as follows

05 - Open Circuit in Brake Switch Harness

11 - Open Circuit in Right Front ABS Wheel-Speed Sensor or related wiring
12 - Open Circuit in Left Front ABS Wheel-Speed Sensor or related wiring
13 - Open Circuit in Right Rear ABS Wheel-Speed Sensor or related wiring
14 - Open Circuit in Left Rear ABS Wheel-Speed Sensor or related wiring

15 - ABS Wheel Speed Sensor signal out of specification : Short circuit of ABS wheel-speed sensor : Damaged ABS sensor rotor : Malfunction of ABS wheel speed sensor : Incorrect clearance between ABS wheel-speed sensor and sensor rotor
41 - Right Front ABS wheel-speed sensor signal out of specification : Short circuit of ABS wheel-speed sensor : Damaged ABS sensor rotor : Malfunction of ABS wheel speed sensor : Incorrect clearance between ABS wheel-speed sensor and sensor rotor
42 - Left Front ABS wheel-speed sensor signal out of specification : Short circuit of ABS wheel-speed sensor : Damaged ABS sensor rotor : Malfunction of ABS wheel speed sensor : Incorrect clearance between ABS wheel-speed sensor and sensor rotor
43 - Right Rear ABS wheel-speed sensor signal out of specification : Short circuit of ABS wheel-speed sensor : Damaged ABS sensor rotor : Malfunction of ABS wheel speed sensor : Incorrect clearance between ABS wheel-speed sensor and sensor rotor
44 - Left Rear ABS wheel-speed sensor signal out of specification : Short circuit of ABS wheel-speed sensor : Damaged ABS sensor rotor : Malfunction of ABS wheel speed sensor : Incorrect clearance between ABS wheel-speed sensor and sensor rotor

22 - Right Front pressure reduction valve malfunction : Replace ABS hydraulic unit
23 - Right Front pressure retention valve malfunction : Replace ABS hydraulic unit
24 - Left Front pressure reduction valve malfunction : Replace ABS hydraulic unit
25 - Left Front pressure retention valve malfunction : Replace ABS hydraulic unit
26 - Rear pressure reduction valve malfunction : Replace ABS hydraulic unit
27 - Rear pressure retention valve malfunction : Replace ABS hydraulic unit

51 - Valve relay power supply : open or short to ground in circuit between ABS control module and battery : Internal failure of ABS control module
52 - Valve relay power supply : open or short to ground in circuit between ABS control module and battery : Internal failure of ABS control module
53 - ABS motor relay : open or short to ground in circuit between ABS control module and battery : ABS fuse (60 amp) blown : Internal failure of ABS control module
54 - ABS motor relay : open or short to ground in circuit between ABS control module and battery : ABS fuse (60 amp) blown : Internal failure of ABS control module

61 - Malfunction of ABS control module
63 - ABS control module power supply malfunction : Malfunction of alternator : Open/short/high resistance of related wiring harness : Low battery voltage ; Malfunction of ABS control module

(Updated December 2023)