Dtc P0724 Tcc Brake Switch Circuit Low (Stuck Off) - Isuzu Trooper 1999 Workshop Manual

7A1–54 TRANSMISSION CONTROL SYSTEM (4L30–E)

DTC P0724 TCC Brake Switch Circuit Low (Stuck Off)

Circuit Description
The TCC brake switch is used to indicate brake pedal
status. The normally opened brake switch signal voltage
supplies a B+ signal on circuit GRN/YEL to the PCM when
the brakes are applied. The PCM uses this signal to de
energize the TCC solenoid when the brakes are applied.
This DTC detects an open brake switch during
decelerations. This is a type "D" DTC.
Conditions For Setting The DTC
f No OSS DTCs P0722 or P0723.
f The PCM detects an open brake switch/circuit (0
volts) during decelerations and the following events
occur seven consecutive times: vehicle speed is
greater than 32 km/h (20 mph) for 4 seconds; then
vehicle speed is between 8 and 32 km/h (5 and 20
mph) for 4 seconds; then vehicle speed is less than 8
km/h (5 mph).
Action Taken When The DTC Sets
f The PCM will not illuminate the Malfunction Indicator
Lamp (MIL).
Conditions For Clearing The DTC
f The DTC can be cleared from the PCM history by
using a scan tool.
f The DTC will also be cleared from history when the
vehicle has achieved 40 warmup cycles without a
failure reported.
f The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled "off"
long enough to power down the PCM.
Diagnostic Aids
f Inspect the wiring for poor electrical connection at the
PCM. Look for possible bent, backed out, deformed
or damaged terminals.
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.
f When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.
f Check customer driving habits and/or unusual traffic
conditions (i.e. stop and go, expressway).
f Check brake switch for proper mounting and
adjustment.
Test Description
The numbers below refer to the step numbers on the
diagnostic chart:
3. This test checks for voltage at the brake switch.
6. This test checks the brake switch.
D07RW005
Check for weak terminal