Isuzu KB P190. Manual — part 576
6E–134
ENGINE DRIVEABILITY AND EMISSIONS
10
Using the DVM and check the IAT sensor ground
circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the IAT sensor connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specified value?
Less than 1V
Go to Step 11
Repair faulty
harness and
verify repair
11
Using the DVM and check the IAT sensor ground
circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM
disconnected) Refer to 6E-88 page.
3. Disconnect the IAT sensor connector.
4. Check the circuit for open circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the IAT sensor connector.
3. Check the circuit for open circuit.
Was the problem found?
—
Repair faulty
harness and
verify repair
Go to Step 14
12
Substitute a known good IAT sensor assembly and
recheck.
Was the problem solved?
—
Go to Step 13
Go to Step 14
13
Replace the IAT sensor assembly.
Is the action complete?
—
Verify repair
—
14
Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?
—
Verify repair
Go to Step 15
Step
Action
Value(s)
Yes
No
V
C121
2
J2-1
Breaker Box
C-121
2
Ω
C56(J2)
C121
2
1
ENGINE DRIVEABILITY AND EMISSIONS
6E–135
15
Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.
—
Verify repair
—
Step
Action
Value(s)
Yes
No
6E–136
ENGINE DRIVEABILITY AND EMISSIONS
DIAGNOSTIC TROUBLE CODE (DTC) P0117 ENGINE COOLANT
TEMPERATURE SENSOR LOW INPUT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The engine coolant temperature (ECT) sensor is a
thermistor mounted in the engine coolant stream. The
engine control module (ECM) applies a voltage (about 5
volts) through a pull-up resistor to the ECT signal circuit.
When the engine coolant is cold, the sensor (thermistor)
resistance is high, therefore the ECM will measure a
high signal voltage. As the engine coolant warms, the
sensor resistance becomes lower, and the ECT signal
voltage measured at the ECM drops. Diagnostic Trouble
code P0117 set when the ECM detects an excessively
low signal voltage on the engine coolant temperature
sensor signal circuit.
Diagnostic Aids
Check for the following conditions:
• Poor connection at ECM - Inspect harness
connectors for backed-out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal-to-wire connection.
• Damaged harness - Inspect the wiring harness for
damage, short to ground, short to battery positive,
and open circuit. If the harness appears to be OK,
observe the ECT display on the Tech 2 while moving
connectors and wiring harnesses related to the ECT
sensor. A change in the ECT display will indicate the
location of the fault.
Code
Type
DTC Name
DTC Setting Condition
Fail-Safe (Back Up)
P0117
A
Engine Coolant Temperature Sensor
Low Input
1. Engine run time is longer than 120 sec-
onds.
2. ECT sensor output is more than 149 deg.
C.
The ECM uses default engine coolant
temperature value based on intake air
temperature and engine run time.
ENGINE DRIVEABILITY AND EMISSIONS
6E–137
Diagnostic Trouble Code (DTC) P0117
Engine Coolant Temperature Sensor Low Input
Step
Action
Value(s)
Yes
No
1
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—
Go to Step 2
Go to On Board
Diagnostic
(OBD) System
Check
2
1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor By Priority” in “F0:
Diagnostic Trouble Code”.
Is the DTC P0117 stored as “Present Failure”?
—
Go to Step 3
Refer to
Diagnostic Aids
and Go to Step
3
3
1. Using the Tech2, ignition “On” and engine “Off”.
2. Select “Clear DTC Information” with the Tech2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F5: Failed
This Ignition” in “F2: DTC Information”.
Was the DTC P0117 stored in this ignition cycle?
—
Go to Step 4
Refer to
Diagnostic Aids
and Go to Step
4
4
Check for poor/faulty connection at the ECT sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
—
Verify repair
Go to Step 5
5
Visually check the ECT sensor.
Was the problem found?
—
Go to Step 8
Go to Step 6
6
Using the DVM and check the ECT sensor.
1. Ignition “Off”, engine “Off”.
2. Disconnect ECT sensor connector.
3. Measure the resistance of ECT sensor.
Does the tester indicate standard resistance as shown
in the following table?
Standard
resistance
Go to Step 7
Go to Step 8
E60(J1)
E69
32
27
Temperature (°C)
Resistance (
Ω) (Approximately)
-20
26740
0
9120
20
3500
40
1464
60
664
80
333
100
175
120
102
2
1
ECT Sensor
Ω
1
2
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст