User's Manual

9
ABS Indicator Lamp Operation (Bulb Check)
The Bendix
®
ESP
®
EC‑80
™
Controller will illuminate the
ABS Indicator Lamp for approximately three seconds when
ignition power is applied, after which the lamp will extinguish
if no Diagnostic Trouble Codes (DTCs) are detected.
The Controller will illuminate the ABS Indicator Lamp
whenever full ABS operation is not available due to a DTC.
In most cases, partial ABS is still available.
ATC/ESP Status/Indicator Lamp Operation
The Bendix ESP EC‑80 Controller will illuminate the ATC/
ESP lamp for approximately 2.5 seconds when ignition
power is applied, after which the lamp will extinguish if
no DTCs are detected. The Controller will continuously
illuminate the ATC/ESP Indicator Lamp whenever ESP or
ATC is disabled due to a DTC.
During an ESP or ATC intervention, the lamp will ash
rapidly (2.5 times per second). When the Controller is
placed in the ATC Mud/Snow (off‑road) mode, the lamp
will ash slowly at a rate of once every 2.5 seconds.
Trailer ABS Indicator Lamp Operation
The Controller will control the Trailer ABS Indicator Lamp
when a PLC signal (SAE J2497) from a trailer ABS ECU
is detected.
Hill Start Assist (HSA) Indicator Lamp Operation
Vehicles with HSA enabled, will illuminate the HSA
Indicator Lamp when ignition power is applied. The lamp
will extinguish if there are no issues with the HSA system.
Pressure Modulator Valve (PMV) and Traction
Control Valve (TCV) Chuff Test
Driver
Right Steer
Left Steer
Right
Additional
Left
Additional
Right Drive
Left Drive
FIGURE 11 - VEHICLE ORIENTATION (TYPICAL)
After the performance of the conguration test, the Bendix
ESP EC‑80 Controller will perform a Bendix‑patented PMV
and TCV Chuff Test. The Chuff Test is an electrical and
pneumatic PMV test that can assist maintenance personnel
in verifying proper PMV wiring and installation.
When ignition power is applied, each modulator solenoid
is briey energized. If the air system is fully charged and
the service brake pedal is depressed during ignition, the
modulator creates a single, sharp audible “chuff” of air
pressure. The modulators are energized in a certain
pattern: right front; left front; right rear; then left rear.
This test is performed only when the vehicle is stationary
(if the vehicle moves, the Chuff Test will not be performed).
The Bendix ESP EC‑80 Controller will perform a PMV
Chuff Test on all installed modulators in the following order:
• Steer Axle Right PMV;
• Steer Axle Left PMV;
• Drive Axle Right PMV;
• Drive Axle Left PMV;
• Additional Axle Right PMV;
• Additional Axle Left PMV; then
• Drive Axle TCV
The pattern will then repeat itself. See Figure 11.
Vehicles with a Bendix ESP EC‑80 Controller — following
the completion of the second round of PMV & TCV Chuff
Tests — the Controller (if congured to do so) will perform
a test to cross‑check the trailer PMV operation with the
vehicle stop lamps. If the trailer PMV circuit is mis‑wired
(including the steer axle TCV), the PMV will exhaust a large
amount of air, or none at all.
NOTICE: If there are any active DTCs, the stop lamp
cross‑check portion of the Chuff Test will not be carried out
until all DTCs are fully diagnosed and the corresponding
repairs are successfully conducted. The ESP/ATC dash
indicator will also illuminate when there are active ABS,
ATC or ESP DTCs.
The ECU will not perform the PMV Chuff Test when wheel
speed sensors show that the vehicle is in motion.
ABS OPERATION
Bendix
®
ABS uses wheel speed sensors, ABS pressure
modulator valves, and an ECU to control either four or six
wheels of a vehicle. The Bendix ESP EC‑80 Controller
monitors individual wheel turning motion during braking,
and adjusts or modulates the brake pressure at the wheel
end. When excessive wheel slip — or wheel lock‑up — is
detected, the Bendix ESP EC‑80 Controller will activate
the pressure modulator valves to automatically reduce
the brake pressure at one or more of the wheel ends.
By these actions, the ABS system helps to maintain the
vehicle's lateral stability and steerability during heavy brake
applications and during braking on slippery surfaces.
Steer Axle Control
Although both wheels of the steer axle have their own
wheel speed sensor and pressure modulator valve, the
Bendix ESP EC‑80 Controller blends the applied braking
force between the two steering axle brakes. This Bendix
patented brake application control, called Modified
Individual Regulation (MIR), is designed to help reduce
steering wheel pull during an ABS event on road surfaces
with poor traction, or areas of poor traction (e.g. asphalt
road surfaces with patches of ice).