James Dillon

30 November 2011  

Symptoms

A relay (K25) in the under bonnet fusebox is responsible for supplying the ABS Pump with a voltage from relay pin 5 to ECU pin 15 of the modulator multiplug. The pump is continuously grounded via pin 8 so anytime it receives a voltage via the relay, the pump should run. The relay is switched via relay terminals 1 and 2, by the ETS ECU, terminals 13 and 12 (bottom of photo). During the actuator test, neither the relay nor the pump is actuated so either the relay or wiring or pump has failed, or the Traction Control ECU has suspended the test whilst the fault code is present in the system. This is quite likely as the relay voltage supply and ground are controlled directly by the Traction Control ECU.