Isuzu 4HL1, Workshop Manual

Page: 97 / 267

Engine Control System 1A-95
7
Check the harness between ECM and CMP
sensor for open wiring or short.
1. Disconnect the CMP sensor connector.
2. Jumper the CMP sensor connector pins
and measure the resistance at the ECM
connector.
Was the resistance within range?
Pins 27-8
(jumpered:
pins 2-3): 0
Ω
(not jumpered):
∞ Ω
Pins 26-8
(jumpered:
pins 1-3): 0
Ω
(not jumpered):
∞ Ω
Pins 26-27
(jumpered:
pins 1-2): 0
Ω
(not jumpered):
∞ Ω
Pins 26/27/8-
ground:
∞ Ω
Go to Step 9 Go to Step 8
8
Repair or replace the faulty harness.
Is the action complete?
—
Verify repair and
go to Step 13 —
9
Check the CMP sensor.
1. At the CMP sensor connector pins,
measure the resistance.
Was the resistance within range?
[Reference]
Pins 1-2:
∞Ω
Pins 2-3:
Approx.
120~130
Ω
Pins 1-3:
∞ Ω
Pin 1/2/3-
sensor body:
∞ Ω
Go to Step 11 Go to Step 10
10
Replace the CMP sensor.
Is the action complete?
—
Verify repair and
go to Step 13 —
11
Review the DTC.
1. Certainly connect the CMP sensor and
ECM connectors.
2. Using Tech 2, clear the DTC.
3. Perform test run and review the DTC.
Is DTC14 detected?
—
Go to Step 12
Refer to
Diagnostic Aids
12
1. Replace the ECM.
IMPORTANT:
If necessary (for the vehicle equipped with
idle stop function), input the number of
startups to the replacing ECM.
Is the action complete?
—
Verify repair and
go to Step 13 —
13
Check DTC14 will not be set again.
1. Using Tech 2, clear the DTC.
2. Perform test run and review the DTC.
Is DTC14 detected?
—
Refer to
Diagnostic Aids
and go to Step 2
Repair is
complete
Step Action Value(s) Yes No