Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Cybertrucker]

I'm revisiting the problem with my speedo, having left it until I knew whether the car was going to pass its MOT.  I've just been studying the wiring diagrams in Haynes, and it appears that the speed signal from the ABS ECU is fed to the following:

Power steering (which is speed-sensitive)
Engine Management System
Cruise control
Multi Instrument Display (for the digital speedo, presumably)

All okay so far - these things need to know how fast you're going, and they all have a problem on my car, which points to no speed signal from the ABS.

However, according to my reading of the diagrams the speed signal is also fed to the sunroof and the radio. What???  The sunroof module on the diagram has "> 120 KM/HR" on it - is the sunroof supposed to close above 120km/hr?  And why on earth would the radio want to know how fast you're going?

[TheBoy]

Radio has SDVC (Speed Dependent Volume Curve/Control)

[dbug]

I'm revisiting the problem with my speedo, having left it until I knew whether the car was going to pass its MOT.  I've just been studying the wiring diagrams in Haynes, and it appears that the speed signal from the ABS ECU is fed to the following:

Power steering (which is speed-sensitive)
Engine Management System
Cruise control
Multi Instrument Display (for the digital speedo, presumably)

All okay so far - these things need to know how fast you're going, and they all have a problem on my car, which points to no speed signal from the ABS.

However, according to my reading of the diagrams the speed signal is also fed to the sunroof and the radio. What???  The sunroof module on the diagram has "> 120 KM/HR" on it - is the sunroof supposed to close above 120km/hr? And why on earth would the radio want to know how fast you're going?

Because the radio volume automatically increases around 60mph!!

Edit - As TB said above (beat me to it)

[TheBoy]

I'm revisiting the problem with my speedo, having left it until I knew whether the car was going to pass its MOT.  I've just been studying the wiring diagrams in Haynes, and it appears that the speed signal from the ABS ECU is fed to the following:

Power steering (which is speed-sensitive)
Engine Management System
Cruise control
Multi Instrument Display (for the digital speedo, presumably)

All okay so far - these things need to know how fast you're going, and they all have a problem on my car, which points to no speed signal from the ABS.

However, according to my reading of the diagrams the speed signal is also fed to the sunroof and the radio. What???  The sunroof module on the diagram has "> 120 KM/HR" on it - is the sunroof supposed to close above 120km/hr? And why on earth would the radio want to know how fast you're going?

Because the radio volume automatically increases around 60mph!!

It increases at all speeds

[dbug]

I'm revisiting the problem with my speedo, having left it until I knew whether the car was going to pass its MOT.  I've just been studying the wiring diagrams in Haynes, and it appears that the speed signal from the ABS ECU is fed to the following:

Power steering (which is speed-sensitive)
Engine Management System
Cruise control
Multi Instrument Display (for the digital speedo, presumably)

All okay so far - these things need to know how fast you're going, and they all have a problem on my car, which points to no speed signal from the ABS.

However, according to my reading of the diagrams the speed signal is also fed to the sunroof and the radio. What???  The sunroof module on the diagram has "> 120 KM/HR" on it - is the sunroof supposed to close above 120km/hr? And why on earth would the radio want to know how fast you're going?

Because the radio volume automatically increases around 60mph!!

It increases at all speeds

Oops - I stand (or sit) corrected Jaime