Dtc P0123 - Tp Sensor Circuit High Voltage - Isuzu Trooper 1999 Workshop Manual

performing the DTC P1121 Diagnostic Chart may isolate
the cause of the fault.
Test Description
Number (s) below refer to the step number(s) on the
Diagnostic Chart.
7. Components that share the TP sensor 5 volt reference
"A" circuit include the following device:
DTC P0123 – TP Sensor Circuit High Voltage
Step
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
2 1. Ignition "ON," engine "OFF."
2. With the throttle closed, observe the "TP Sensor"
display on the Tech 2.(If no, start with diagnosis
chart for other sensors in the circuit and see if 5V
returns.)
Is the "TP Sensor" above the specified value?
3 1. Ignition "ON," engine "OFF."
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor "DTC" info for DTC P0123.
Does the Tech 2 indicate DTC P0123 failed.
4 1. Disconnect the TP sensor electrical connector.
2. Observe the "TP Sensor" display on the Tech 2.
Is the "TP Sensor" near the specified value?
5 Probe the sensor ground circuit at the TP sensor
harness connector with a test light connected to B+.
Is the test light "ON?"
6 1. Ignition "OFF," disconnect the PCM.
2. Ignition "ON," engine "OFF."
3. Check for a short to voltage on the TP sensor signal
circuit.
4. If the TP sensor signal circuit is shorted, repair it as
necessary.
Was the TP sensor signal circuit shorted?
7 1. Ignition "ON."
2. Monitor the "TP Sensor" Tech 2 display while
disconnecting each of the components that share
the 5 volt reference "A" circuit (one at a time).
3. If the "TP Sensor" Tech 2 display changes, replace
the component that caused the display to change
when disconnected.
Does disconnecting any of these components cause
the "TP Sensor" display to change?
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Action
f EGR valve
Disconnect the component while observing the TP
sensor display on the Tech 2. If the reading
changes drastically when this component is
disconnected, replace the component that
affected the reading.
Value(s)
Go to Step 2
—
4.88 V Go to Step 4
— Go to Step 4
Go to Step 5
0 V
— Go to Step 7
— Verify repair
— Verify repair
6E–157
Yes No
Go to OBD
System
Check
Go to Step 3
Refer to
Diagnostic
Aids
Go to Step 6
Go to Step 10
Go to Step 12
Go to Step 8