How to read 2g ABS diagnostic trouble codes using the ABS warning light (these codes are different than the check engine ECU trouble codes):
With ignition switch off, ground pin 1 (pin on left end of longer side) of the OBDII data link connector. Turn ignition switch to ON (engine not running) and count the flashes of the ABS warning light. The first longer flashes (1.5 sec each separated by 0.5 sec) are the tens digit, followed by a 2 sec pause, followed by shorter flashes (0.5 sec each separated by 0.5 sec) for the ones digit. For example a 24 code will have 2 longer flashes, 2 sec pause, 4 shorter flashes. No trouble codes will flash continuous shorter pulses.
OBDII data link connector pinout:
OBDII - On-Board Diagnostic's System - Does My Car Have OBD-II? The Connector and Communications.
ABS Diagnostic Trouble Codes (from ’99 Mitsubishi Eclipse manual):
11 – Front right wheel speed sensor (open circuit)
12 – Front left wheel speed sensor (open circuit)
13 – Rear right wheel speed sensor (open circuit)
14 – Rear left wheel speed sensor (open circuit)
15 – Wheel speed sensor (abnormal output signal)
16 – Power supply system (ABS-ECU power voltage outside standard value)
21 – Front right wheel speed sensor (short circuit)
22 – Front left wheel speed sensor (short circuit)
23 – Rear right wheel speed sensor (short circuit)
24 – Rear left wheel speed sensor (short circuit)
26 – G sensor (open or short)
38 – Stop light switch system
41 – Front right inlet solenoid valve
42 – Front left inlet solenoid valve
43 – Rear right inlet solenoid valve
44 – Rear left inlet solenoid valve
45 – Front right outlet solenoid valve
46 – Front left outlet solenoid valve
47 – Rear right outlet solenoid valve
48 – Rear left outlet solenoid valve
51 – Valve power supply
53 – Pump motor
63 – ABS-ECU
The diagnostic trouble codes can be erased (engine not running) by holding brake pedal down (to turn stop light switch on), turning ignition switch to ON, and then within 3 seconds pumping the brake pedal (stop light switch toggles) 10 times. Each pump must be within 1 second of last. If the repair has been made but the ABS diagnostic trouble code is not erased, the vehicle must exceed 12 km/h to turn off the ABS warning light and re-enable the ABS.
Note1: There has been a report that the grounding trick doesn't work for the Nippondenso ABS ECU, but it does work for the Bosch on early 2g's (
2G GST ABS light just came on...how to diag? - DSM Forums.
