Workshop Manual

6E–399
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
If it is determined that the DTC occurs intermittently,
performing the DTC P1120 Diagnostic Chart may
isolate the cause of the fault.
Diagnostic Trouble Code(DTC)P1120-TPS 1 Output Abnormal
Step Action Value(s) Yes No
1 Was the “On-Board(OBD)System Check” performed?
— Go to Step 2
Go to OBD
System
Check
2 1. Ignition “ON”, engine not running.
2. Observe the MAP reading on the Tech 2.
Is the MAP reading less than the specified value?
65kPa Go to Step 3 Go to Step 6
3 1. Disconnect the MAP sensor.
2. Connect a test 5 volt reference circuit and the MAP
signal at the MAP sensor harness connector.
3. Observe the MAP reading on the Tech 2.
Is the MAP reading less than the specified value? (If no,
start with diagnosis chart for other sensors in the circuit
and see if 5V returns.)
— Go to Step 5 Go to Step 4
4 1. Check the MAP signal circuit between the PCM and
MAP ground circuit.
2. If the MAP signal circuit is open or shorted, repair it
as necessary.
Was the MAP signal circuit open or shorted?
— Verify repair Go to Step 12
5 Replace the MAP sensor.
Is the action complete?
— Verify repair —
6 Observe the TP angle reading on the Tech 2 while
slowly opening the throttle.
Does the TP angle increase steadily and evenly from
the closed throttle value to the wide open throttle
value?
Throttle
Closed TPS1
8–10 % TPS2
8–10 % Wide
Open Throttle
TPS1 90–92
% TPS2
90–92 %
Refer to
Diagnostic
Aids
Go to Step 7
7 1. Disconnect the TP sensor.
2. Observe the TP sensor reading on the Tech 2.
Is the TP sensor reading near the specified value?
0V Go to Step 8 Go to Step 9
8 1. Connect a test light between the 5Volt reference
circuit and the TP sensor signal circuit at the TP
sensor harness connector.
2. Observe the TP sensor reading on the Tech 2.
Is the TP sensor reading near the specified value?
5V Go to Step 11 Go to Step 10
9 Check the following items;
1. TP1 signal circuit for a short to voltage.
2. TP1 sensor ground circuit for high resistance
between the PCM and the TP sensor.
3. TP1 sensor ground circuit for a poor connection.
4. If a problem is found, repair wiring harness as
necessary.
Was a problem found?
— Verify repair Go to Step 12