BENDIX TABS-6 - Troubleshooting Flowcharts - Power Supply; Power Supply Troubleshooting

37
Measure the loaded
voltage across a type
1157brakelightbulb.
LookingintoTABS-6
Advanced MC Module 7‑pin
Connector Pigtail Harness
Measure:
IgnitionPower(pin1)to
Ground (pin 4), and
BrakeLampPower(pin2)
to Ground (pin 4).
SECTION D: TROUBLESHOOTING THE
POWER SUPPLY
Turn off the power to the
module,disconnectthe7-pinECU
connector.
Check for high resistance
(corrosion, wire/connector damage
or improper termination) of the
power lines, resulting in a high
voltage drop across the lines.
Measure the voltage under load by
placingaloadsuchasatype1157
brake light bulb between the Ignition
Power pin and Ground pin of the
ECUconnector,whilethelampisin
place.
With ignition power to the trailer,
measure the voltage between the
IgnitionPower(pin1)andGround
(pin4)oftheECUconnector.
Repeat the voltage measurement
with brake lamp power to the trailer,
betweentheBrakeLampPower
(pin 2) and the Ground (pin 4) of the
ECUconnector.
The operating range of the module
is8.0-32.0VDC.Verifythatthe
voltage drop measurements are no
lessthan1.0VDCfromthevehicle
voltage at both the ignition and
brake power inputs
With a volt/ohm meter, check
thepowerandgroundwiring.Look
for corroded or damaged wires or
connectors.
If repairs are made, rerun the
power-upsequence.Goto
Section A.
If proper loaded and unloaded
voltageismeasuredattheECU
connector, and no corrosion or
damage is found on the wiring,
connectorsorECU,replacethe
module.
With a volt/ohm meter, check the
powerandgroundwiring.Lookfor
corroded or damaged wire or connectors.
If repairs are made, rerun the power‑up
sequence.GotoSectionA.
With
ignition
power to
the trailer (engine
running), measure the
voltage between the ignition
Power pin and the Ground pin of the
ECUconnector.
Repeat the voltage measurement with brake lamp
powertothetrailer,andbetweentheBrakeLampPower
pinandtheGroundpinoftheECUconnector.
The operating range of the module is
8.0-32.0VDC.Canyouverifythat
measurementsfoundareequal
to the vehicle voltage (within
1VDC)atboththe
ignition and brake
power
inputs?
NO
YES