Isuzu C22NE Workshop Manual page 300

6E1-130 DRIVEABILITY AND EMISSIONS
Step
Was the "On-Board Diagnostic (OBD) System Check "
1 performed?
1. Ignition ON, engine OFF.
2. Monitor the TP value on the Scan Tool While moving
2 the throttle between 0% and 100%.
Does the TP value on the Scan Tool move smoothly from
0% (0.25 volts) to 100% (4.75 volts)?
1. Ignition OFF.
2. Disconnect the Throttle Position (TP) Sensor electrical
connector, located on the RH side of the Throttle body.
3 3. Start the engine, and monitor the TP value with the
Scan Tool.
Does the TP value on the Scan Tool hold steadily within
the given range?
Check the TP sensor signal circuit, between the TP
sensor and the Engine Control Module (ECM), for a short
4
to voltage.
Was the problem found?
Check the TP sensor signal circuit, between the TP
sensor and the ECM, the following conditions:
• A short to ground
5
• An open circuit
Was the problem found?
Check the 5 Volt signal circuit between the TP sensor and
the ECM, for the following conditions:
• An Open Circuit
6
• A short to ground
• A short to voltage
Was the problem found?
1. Ignition OFF.
2. Place a fused jumper between the TP sensor circuit
and the 5 volt signal circuit both at the wiring harness
7 TP sensor connector.
3. Ignition ON, engine OFF.
4. Observe the TP value displayed on the Scan Tool.
Does the Scan Tool read the following value?
Check the TP sensor ground circuit, between the TP
sensor and the ECM, for the following conditions:
• An Open Circuit
8
• A short to ground
• A short to voltage
Was the problem found?
TP Sensor Circuit Range/Performance Problem
Action Value(s) Yes
-
Go to Step 2
-
Go to Step 3
0-0.25 volts
0%
Go to Step 5
-
Verify Repair
-
Verify Repair
-
Verify Repair
about 5 volts
100%
Go to Step 8
-
Verify Repair
No
Go to OBD
System
Check
Go to Step 10
Go to Step 4
Go to Step 11
Go to Step 6
Go to Step 7
Go to Step 11
Go to Step 9