Bendix Commercial Vehicle Systems GEN 5 ABS - Manual (Page 26)

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The 17•12 Sensor Memory Diagnostic Trouble
Code
The ABS indicator lamp indication and 17•12 diagnostic
trouble code are provided to remind the service technician
of the need to verify the performance of the ABS wheel
speed sensors by driving the vehicle after servicing the
sensors. ABS wheel speed sensors do not generate signals
unless the wheels are turning. Because of this, certain
sensor codes can only be detected when the vehicle is in
motion.
The trouble code 17•12 is generated after the initial sensor
codes are cleared. The ABS indicator lamp remains lit.
The trouble codes must be rechecked after clearing the
sensor codes in order to see 17•12 reported.
A 17•12 trouble code and ABS indicator lamp signal for
sensor code cannot be cleared using a ProLink,
ServiceRanger software or the diagnostic button. They can
only be cleared by driving the vehicle. The ABS ECU will
clear the 17•12 blink code and turn off the ABS indicator
lamp when all active sensor code issues are resolved and
the vehicle is driven above 5 mph. The ABS ECU must
detect speeds at all monitored wheels for the condition to
clear.
Procedure:
1. Check trouble codes.
2. Troubleshoot and eliminate causes for all trouble codes.
3. Clear trouble codes.
4. Check trouble codes again (17•12 will be reported if
sensor codes are cleared).
5. If 17•12 error code is reported, drive vehicle above 5
mph (ABS indicator lamp will go out and 17•12 trouble
code will be cleared after a short period if all sensor
signals are acceptable).
Note: If sensor codes still exist, the ABS indicator lamp
will remain lit. The trouble codes will be logged once again
after driving the vehicle. If more than one sensor site is
affected, the codes may not be re-logged by the ECU until
the vehicle has been driven and held above 20 mph for 3-
5 minutes.
For more detailed troubleshooting, monitor the wheel
speeds and cut-out speeds with ServiceRanger or a ProLink
hand-held diagnostic tool. Troubleshoot and repair any
speed sensor not reporting a wheel speed or showing a
high cut-out speed.
Cut-out speeds are an indication of the strength of the
sensor signal to the ECU and are proportional to air gap.
Cut-out speeds should be in the range of 3-8 mph. Lower
numbers indicate a stronger and better signal than higher
numbers. High values indicate a sensor with an unreliable
or non-existent signal.