Hello.
I have a Ford Ranger 2004, 2.3l, automatic transmission, 2 WD, 4 ABS
ABS light is on
Forscan diagnostics shows an error:
Failure in the input circuit of the central rear speed sensor
This DTC can be caused by:
open circuit
-short circuit to power circuit
Short circuit to ground
-connected electrical wiring connectors
sensor defective
-malfunction of the ABS module is possible
I replaced the ABS sensor - the situation has not changed
Next, I will check the wiring and connectors from the ABS sensor to the ABS module
Do you have a wiring diagram from the sensor to the module?
What else can I check with this error?
Thank you

 

What was the exact code number?

Here is a 2006 diagram should be same as 2004
2003 was the same wire colors and pins just different fuse numbers, because 2004 got the new SJB fuse box

 

code C1230
thank

 

Was the new sensor motorcraft?
C1230 is a common Ford ABS code, it is usually fixed with new VSS 90% of the time, so very rarely does a new WORKING VSS not fix the problem, and code will clear itself within one drive cycle if problem is repaired

And did the old sensor look damaged at all, like something hit it?
There is a reluctor ring with teeth inside differential, that's what the VSS reads as axle is spinning, picture here: http://www.fordrangerforum.com/membe...-ring-gear.jpg
Its the thin one, and while rare it can move/shift position or break
The VSS generates its own voltage from the spinning teeth passing by it, so you can test these with wheels up and spinning, should see AC voltage on a meter, under 1 volt AC at lower speed


You can test the sensor wires with an OHM meter to Ground
One wire will show close to 0 ohms since it is grounded, in the module, usually red/pink one, if not wire is broken
Other wire should have HIGH ohms to ground, but should have ohms shown, if not wire is broken
Then test ohms between the two wires, should also be HIGH ohms, if not then wires are shorted

 

New DORMAN 970012 Sensor Installed
The old sensor had no external damage, the connector is also in good condition.
Today I will check the differential ring and wiring diagram.
thank

 

Thanks to Ron for the wiring diagram.
The wiring diagram is fully consistent with the 2004 Ford Ranger.
I checked the wires between the rear speed sensor connector and the ABS module connector.
One wire had an open circuit, although the wiring had no visible damage.
I replaced the wire between the connectors. The ABS lamp went out.
I deleted the error in the memory of the ABS module by the Forskan program.

 

Good work

Hope that fixes the problem

Thanks for the follow up post and the conformation of wiring colors and pins