ABS-equipped MGFs and all MG TFs use the Bosch 5.3 three-channel ABS system. Four wheel speed sensors, one at each corner, report rotation speed to a dedicated ABS ECU, which commands solenoid valves inside a hydraulic modulator unit to momentarily reduce brake line pressure at any wheel sensed to be approaching lock-up. The base braking circuit continues to function normally when ABS is inactive; ABS only intervenes when the ECU detects incipient lock-up. ABS was standard on VVC MGFs from launch and optional on 1.8i and 1.6i cars, standardised across the MG TF range from 2004.
Two notable exceptions: the 2001 MGF Trophy 160 SE deleted ABS entirely in favour of a weight-saving, track-focused specification, and pre-ABS MGFs built up to AD000505 have no ABS fitment at all. Parts on this page do not apply to either of those specifications.
Modulator and Bracket, Two Variants Split at XD511059
The ABS modulator assembly and its mounting bracket changed at VIN XD511058/XD511059, the MGF Mk1/Mk2 transition. Pre-XD511058 MGFs use an earlier modulator and mounting bracket with support cups under each of the three mounting bushes. From XD511059 onwards, covering late MGFs and all MG TFs, a revised modulator and a redesigned bracket without support cups are fitted. The modulator listed on this page is the later SRB101590 specification.
The two generations are not interchangeable: the modulator-to-body brake pipe routing and the bracket geometry are specific to each. Owners of pre-XD511058 cars looking for an original-spec modulator should contact MGOC Spares directly for the earlier part. The modulator is retained to its bracket by two M8 flanged nuts, and the bracket to the body by three M6 screws, all catalogued as individual service items.
Wheel Speed Sensors, Three Part Numbers for Four Positions
ABS sensors are not four identical items. The two front sensors share a common specification and are not handed. The two rear sensors, by contrast, are handed LH and RH and must be ordered correctly, the catalogue lists both sides on the live page. All three sensor specifications are MGF/TF-specific and use sealed connectors routed through the wheel arch liners.
Sensor adaptors attach each sensor to its mounting position and are catalogued in two variants paired diagonally, one part covers RH front plus LH rear, the other covers LH front plus RH rear. Adaptor securing screws are catalogued individually, with M6 x 10mm items for the front and a longer bolt for the rear.
MG TF-Specific Front Sensor Guide Brackets
The front ABS sensor mounting differs between MGF and MG TF. MG TF cars use handed LH and RH guide brackets, catalogued as individual items, which do not appear on MGF cars. These brackets carry the sensor lead routing around the front suspension and are worth renewing when an MG TF front sensor is replaced, as the plastic construction embrittles with age and a broken bracket leaves the sensor lead vulnerable. MGF cars use a different mounting arrangement and do not require the handed brackets.
Common ABS Faults and Diagnosis
The most common ABS fault is wheel speed sensor failure. Sensors sit close to road spray and the connectors corrode over time, while the sensor leads can be damaged during suspension or brake work. The reluctor rings, toothed rings integral to the hubs that the sensors read, accumulate metallic debris that produces erratic signals; cleaning the reluctor face is worth trying before replacing a sensor. Modulator pump failure is less common but does occur: symptoms are ABS activating at inappropriate times or the pump motor running continuously after the engine is started.
ABS faults illuminate the dashboard warning light and are stored as diagnostic codes readable with appropriate equipment. When the ABS warning is on, the ABS function is disabled but the base braking circuit continues to work normally, the car remains safe to drive to a workshop.