Dtc P0724 Brake Switch Circuit High (Stuck Off) - Isuzu 2000 Trooper Workshop Manual

DTC P0724 Brake Switch Circuit High (Stuck Off)

Circuit Description:
The brake switch indicates brake pedal status to the
Powertrain Control Module (PCM). The brake switch is a
normally–closed switch that supplies battery voltage on
circuit ORN to the PCM. Applying the brake pedal opens
the switch, interrupting voltage to the PCM. When the
brake pedal is released, the PCM receives a constant
voltage signal. If the PCM receives a zero voltage signal
at the brake switch input, and the Torque Converter
Clutch (TCC) is engaged, the PCM de–energizes the
Torque Converter Clutch Solenoid Valve (TCC Sol.
Valve). The PCM disregards the brake switch input for
TCC scheduling if there is a brake switch circuit fault
(Refer to Diagnostic Aids).
When the PCM detects a closed brake switch circuit (12
volts, high input) during decelerations, then DTC P0724
sets. DTC P0724 is a type D DTC.
Conditions For Setting The DTC
 No OSS Assy. DTCs P0722 or P0723.
 The PCM detects a closed brake switch circuit (12
volts) without changing and the following events
occur seven consecutive times:
 The vehicle speed is greater than 32 km/h (20 mph)
for 4 seconds;
 then the vehicle speed is between 8–32 km/h (5–20
mph) for 4 seconds;
 then the vehicle speed is less than 8 km/h (5 mph).
TRANSMISSION CONTROL SYSTEM (4L30–E)
Action Taken When The DTC Sets
 The PCM does not illuminate the Malfunction
Indicator Lamp (MIL).
 DTC P0724 stores in PCM history.
Conditions For Clearing The DTC
 A scan tool can clear the DTC from the PCM history.
The PCM clears the DTC from the PCM history if the
vehicle completes 40 warm–up cycles without a
failure reported.
 The PCM cancels the DTC default actions when the
fault no longer exists and the ignition is OFF long
enough in order to power down the PCM.
Diagnostic Aids
 Inspect the wiring for poor electrical connection at the
PCM. Look for possible bent, backed out, deformed
or damaged terminals. Check for weak terminal
tension as well. Also check for a chafed wire that
could short to bare metal or other wiring. Inspect for a
broken wire inside the insulation.
 When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.
 Check customer driving habits and/or unusual traffic
conditions (i.e. stop and go, expressway).
 Check brake switch for proper mounting and
adjustment.
7A1–51
D07RY00012