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Isuzu engine C22NE / 22LE / 20LE. Manual - part 95

DRIVEABILITY AND EMISSIONS 6E1-209

DTC (Flash DTC = 56)

Check Engine Lamp Low Error (Cont’d)

Step

Action

Value(s)

Yes

Locate and repair the open ECM battery feed circuit.

Is the action complete?

Verify repair

Locate and repair the short to ground in the ECM battery

feed circuit.

Is the action complete?

Verify repair

Locate and repair the short to ground in the MIL feed

circuit to the instrument cluster, and replace the fuse.

Is the action complete?

Verify repair

Replace the EPROM or ECM.

Note) Refer to 6E1-243.

Verify repair

Check the MIL driver circuit for a poor connection at the

instrument panel connector.

Was a problem found?

Verify repair

Go to

Instrument

Panel in

Electrical

Diagnosis

6E1-210 DRIVEABILITY AND EMISSIONS

DRIVEABILITY AND EMISSIONS 6E1-211

HOT AT ALL TIMES

ECM

Fuse

15A

U/H

FUSE

BLOCK

HOT IN START AND RUN

Meter

Fuse

15A

I/P

FUSE

BLOCK

Malfuntion

Indicator

Lamp

0.85

YEL

1.25

RED/

WHT

1.25

RED/

WHT

0.5

BR/Y

Instrument

Panel(I/P)

Cluster

Engine

Control

Module

(ECM)

Batt+

Malfunction

Indicator

Lamp

Control

TACHO

DIAGNOSTIC TROUBLE CODE (DTC) 57 (Flash DTC = 57)

CHECK ENGINE LAMP HIGH ERROR

Circuit Description

The malfunction indicator lamp (MIL) should always be

illuminated and steady with the ignition ON and the

engine stopped. Battery feed voltage is supplied

directly to the MIL indicator. The engine control

module (ECM) turns the MIL ON by grounding the MIL

driver circuit.

Conditions for setting the DTC

• This code detects a low impedance short to battery

on the MIL output.

• Driver feedback information shows a low state at its

operation even when commanded high.

Action Taken when the DTC sets

• The MIL will stay ON.

Conditions for Clearing the DTC

Once the ECM determines that a fault(s) has been

rectified then the CEL will switch OFF, although the

fault code will remain in the ECM memory.

Any fault codes will remain in ECM memory until -

1. They are cleared by disconnecting the Battery for

more than 30 seconds.

2. A service tool such as Tech 2 is used to clear them.

3. Ten consecutive starts without logging a fault.

6E1-212 DRIVEABILITY AND EMISSIONS

Diagnostic Aids

An intermittent may be caused by a poor connection,

rubbed-through wire insulation, or a wire broken inside

the insulation. Check for the following items:
• Poor connection or damaged harness - Inspect the

ECM harness and connectors for improper mating,

broken locks, improperly formed or damaged

terminals, poor terminal-to-wire connection, and

damaged harness.

Test Description

Number(s) below refer to the step number(s) on the

Diagnostic Chart.

2. If the MIL does not remain ON when the ECM is

disconnected, the MIL driver wiring is not faulty.

3. If the MIL driver circuit is OK, the instrument panel

cluster is faulty.

DTC (Flash DTC = 57)

Check Engine Lamp High Error

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System

Check” performed?

Go to Step 2

Go to OBD

System

Check

1. Ignition OFF, disconnect ECM.

2. Ignition ON, observe the MIL.

Is the MIL ON?

Go to Step 3

Go to Step 5

1. Ignition OFF, disconnect the instrument panel cluster.

2. Check the MIL driver circuit between the ECM and the

instrument panel cluster for a short to battery.

3. If a problem is found, repair as necessary.

Was the MIL driver circuit shorted to battery?

Go to OBD

System

Check

Go to Step 4

Replace the instrument panel cluster.

Is the action complete?

Go to OBD

System

Check

1. Ignition OFF, reconnect the ECM.

2. Refer to On-Vehicle Service in Engine Control Module

and Sensors for procedures.

3. Using the scan tool output controls function, select MIL

dash lamp control and command the MIL OFF.

Did the MIL turn OFF?

Go to OBD

System

Check

Go to Step 6

Replace the EPROM or ECM.

Note) Refer to 6E1-243.

Go to OBD

System

Check

Content .. 93 94 95 96 ..