Content .. 684 685 686 687 ..

Isuzu N-Series. Manual - part 686

6E-166 Engine Control System (4HK1)

Is the DMM voltage more than the specified value
at Step 3?

—

Go to Step 9

Go to Step 8

Turn OFF the ignition.

Connect a DMM between the signal circuit
(pin 2 of E-112 connector) and battery voltage.

Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

22 volts

Go to Step 6

Go to Step 10

Turn OFF the ignition.

Connect a test lamp between the signal circuit
(pin 2 of E-112 connector) and battery voltage.

Connect a DMM between the probe of the test
lamp and battery voltage.

Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

22 volts

Go to Step 11

Go to Step 7

Turn OFF the ignition.

Connect a test lamp between the shield circuit
(pin 1 of E-112 connector) and battery voltage.

Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

—

Go to Step 13

Go to Step 12

Test the CMP sensor 12 reference circuit
between the engine control module (ECM)
(pin 99 of E-111 connector) and the CMP
sensor (pin 3 of E-112 connector) for the
following conditions:

• An open circuit
• A short to ground
• A short to any 5 volts reference
• A short to the signal circuit
• A short to the shield circuit
• High resistance

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 14

Test the CMP sensor 12 volts reference circuit
between the ECM (pin 99 of E-111 connector)
and the CMP sensor (pin 3 of E-112
connector) for short to battery or ignition
voltage.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 18

Step

Action

Value(s)

Yes

Engine Control System (4HK1) 6E-167

Important:
The CMP sensor may be damaged if the sensor
signal circuit is shorted to a voltage source.

Test the CMP sensor signal circuit between
the ECM (pin 98 of E-111 connector) and the
CMP sensor (pin 2 of E-112 connector) for the
following conditions:

• An open circuit
• A short to battery or ignition voltage
• A short to any 5 volts reference
• High resistance

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 14

Test the CMP sensor signal circuit between
the ECM (pin 98 of E-111 connector) and the
CMP sensor (pin 2 of E-112 connector) for a
short to ground or short to the shield circuit.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 18

Important:
The ECM may be damaged if the sensor shield
circuit is shorted to a voltage source.

Test the CMP sensor shield circuit between
the ECM (pin 100 of E-111 connector) and the
CMP sensor (pin 1 of E-112 connector) for the
following conditions:

• An open circuit
• A short to battery or ignition voltage
• High resistance

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 14

Turn OFF the ignition.

Inspect for an intermittent and for poor
connections at the harness connector of the
CMP sensor (pins 1, 2 and 3 of E-112
connector).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 15

Turn OFF the ignition.

Disconnect the ECM harness connector.

Inspect for an intermittent and for a poor
connection on these CMP sensor circuits at
the harness connector of the ECM (pins 98,
99 and 100 of E-111 connector).

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 18

Step

Action

Value(s)

Yes

6E-168 Engine Control System (4HK1)

Remove the CMP sensor. Refer to Camshaft
Position (CMP) Sensor Replacement in this
section.

Visually inspect the CMP sensor for the
following conditions:

• For physical damage
• For being loose
• For improper installation

Did you find and correct the condition?

—

Go to Step 19

Go to Step 16

Visually inspect the camshaft gear surface for
damage.

Did you find and correct the condition?

—

Go to Step 19

Go to Step 17

Replace the CMP sensor. Refer to Camshaft
Position (CMP) Sensor Replacement in this
section.

Did you complete the replacement?

—

Go to Step 19

—

Important:
Replacement ECM must be programmed.

Replace the ECM. Refer to Engine Control Module
(ECM) Replacement / Fuel Injector ID Code Data
Programming in this section.

Did you complete the replacement?

—

Go to Step 19

—

Reconnect all previously disconnected
harness connector(s).

Clear the DTCs with the Tech 2.

Turn OFF the ignition for 30 seconds.

Start the engine. If engine does not start,
crank over the engine for 10 seconds.

Did the DTC fail this ignition?

—

Go to Step 3

Go to Step 20

Observe the DTC Information with the Tech 2.

Are there any DTCs that you have not diagnosed?

—

Go to Diagnostic

Trouble Code (DTC)

List

System OK

Step

Action

Value(s)

Yes

Engine Control System (4HK1) 6E-169

P0341 (Flash Code 14)

Circuit Description
The camshaft position (CMP) sensor is installed on the
cylinder head at the rear of the camshaft gear. The
CMP sensor has the following circuits.

• 12 volts reference circuit
• CMP sensor signal circuit
• CMP sensor shield circuit

The engine control module (ECM) supplies 12 volts to
the CMP sensor on the 12 volts reference circuit. The
CMP sensor provides a signal to the ECM on the CMP
signal circuit. The CMP sensor detects a total of five
through holes (four holes arranged equally every 90

and one reference hole on the camshaft gear flange
surface) and sends signals to the engine control
module (ECM). Receiving these signals, the ECM
determines cylinder #1 compression top dead center
(TDC). If the ECM receives extra or missing CMP
sensor signal pulses, this DTC will set.

Condition for Running the DTC

• DTCs P0335, P0336, P0340 and P1345 are not

set.

• The ignition switch is ON.
• The CMP sensor signal pulse is detected.

Condition for Setting the DTC

• The ECM detects extra or missing CMP sensor

pulses during engine rotations.

Action Taken When the DTC Sets

• The ECM illuminates the malfunction indicator

lamp (MIL) when the diagnostic runs and fails.

Condition for Clearing the MIL / DTC

• The ECM turns OFF the MIL when the key is

cycled after a current DTC clears.

• A current DTC clears when the diagnostic runs and

does not fail at next driving cycle.

• A history DTC clears after 20 consecutive driving

cycles without a fault. Or clear with the Tech 2 or
accelerator pedal operation.

Diagnostic Aid

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

• An intermittent CMP sensor signal may set this

DTC.

• Ensure the sensor is tight and the camshaft gear

flange surface is not damaged.

Notice:

• If this DTC is set, the engine cranks but does not

start.

DTC P0341 (Flash Code 14)
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls
Connector End Views or Engine Control Module (ECM)
Connector End Views

Step

Action

Value(s)

Yes

Did you perform the Diagnostic System Check –
Engine Controls?

—

Go to Step 2

Go to Diagnostic

System Check –

Engine Controls

Install the Tech 2.

Turn OFF the ignition for 30 seconds.

Start the engine. If engine does not start,
crank over the engine for 10 seconds.

Monitor the Diagnostic Trouble Code (DTC)
Information with the Tech 2.

Is DTC P0340 also set?

—

Go to DTC P0340

Go to Step 3

Inspect all of the circuits going to the camshaft
position (CMP) sensor for the following:

• Routed too closely to fuel injection wiring

or components

• Routed too closely to after-market add-

on electrical equipment

• Routed too closely to solenoids, relays,

and motors

If you find incorrect routing, correct the
harness routing.

Did you find and correct the condition?

—

Go to Step 9

Go to Step 4

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