Isuzu Trooper 1999 Workshop Manual page 1508

DTC P0724 TCC Brake Switch Circuit Low (Stuck Off)
Step
1 Were you sent here from the "Powertrain On–Board Diagnostic
(OBD) System Check"?
2 1. Install the scan tool.
2. With the engine "off", turn the ignition switch "on".
NOTE: Before clearing DTC(s), use the scan tool to record "Failure
Records" for reference, as data will be lost when the "Clear Info"
function is used.
3. Record the DTC "Failure Records".
4. Apply then release the brake pedal.
Does the scan tool display "TCC Brake Switch" as "closed" with
the brake pedal applied, and then display "open" when the brake
pedal is released?
3 1. Connect the test light to ground.
2. Back probe ignition feed circuit terminal B13–1 at the brake
switch.
Is the test light "on"?
4 1. Connect the test light to ground.
2. Back probe circuit terminal B13–4 at the brake switch.
3. Apply the brake pedal.
Is the test light "on" when the brake pedal is applied?
5 Repair the open in ignition feed circuit terminal B13–1 to the brake
switch. If fuse is open, check circuit terminal B13–4.
Is the repair complete?
6 1. Disconnect B13 connector.
2. Check the resistance between terminal B13–1 and B13–4.
Is the resistance 0 ohm with the brake pedal applied?
7 Check circuit terminal B13–4 for a open.
Was a problem found?
8 Replace the brake switch.
Is the replacement complete?
9 Check PCM for faulty connections.
Was a problem found?
10 Replace the PCM. Refer to Powertrain Control Module (PCM) in
Automatic Transmission (4L30–E) section.
Is the replacement complete?
11 1. After the repair is complete, use the scan tool to select "DTC",
then "Clear Info" function and ensure the following conditions
are met:
The PCM brake switch signal must indicate 12 volts for 1
seconds with the brake pedal released.
2. Review the scan tool "DTC Info".
Has the last test failed or is the current DTC displayed?
TRANSMISSION CONTROL SYSTEM (4L30–E)
Action Yes
Go to OBD
System Check
Driveability and
Emissions in
Go to Step 2 Engine section
Go to Diagnostic
Go to Step 3
Aids
Go to Step 4 Go to Step 5
Go to Step 7 Go to Step 6
Go to Step 11
Go to Step 7 Go to Step 8
Go to Step 11 Go to Step 9
Go to Step 11
Go to Step 11 Go to Step 10
Go to Step 11
Begin diagnosis
again
Repair verified
Go to Step 1
Exit DTC table
7A1–55
No
Refer to
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