DME 7.8 DME 7.8 0 · 0-18P0121

DME 7.8 DME 7.8 0 0-18P0121 117 Throttle valve - signal implausible Diagnosis conditions • Engine running Possible fault cause ♦Open circuit or short circuit in the wiring ♦Throttle position sensor faulty ♦DME control module faulty Affected terminals Terminal I/7, I/9, III/8, III/10, III/24 and III/25 Note! ♦Fault P0121 only appears in conjunction with fault P1121 or P1122. ♦The system operates in pedal sensor standby mode, i.e. the angle of the accelerator pedal is calculated from the residual position sensor signal. ♦The opening angle of the throttle valve is limited to 30 %. ♦The dynamic of the throttle valve is restricted. Diagnosis/troubleshooting Work instruction Display OK If not OK 1 Check voltage supply to ♦Connect special tool 9637 See Figure 1 ⇒ Step 5 throttle motor actuator ♦Connect motor tester (oscillo- scope) to Pin I/7 and Pin I/9 ♦Use special input ♦Switch on the ignition ♦Fully depress accelerator pedal See Figure 2 ⇒ Step 2 2442 P0121 0-18 page 1 Printed in Germany, 2000 p0121