Isuzu N-Series. Manual - part 763

 Engine Control System (4JH1)    6E-103

P0335 (Symptom Code B, D) (Flash Code 43)

Circuit Description
The crankshaft position (CKP) sensor is located on top
of the flywheel housing.  There are 4 slits spaced 90

°

on the flywheel circumference.  The CKP sensor is a
magnetic coil type sensor, which generates an AC
signal voltage based on the crankshaft rotational
speed.  The engine control module (ECM) monitors
both the CKP sensor and injection pump camshaft
position (CMP) sensor signals to ensure they correlate
with each other.
If the ECM receives extra or missing CKP sensor signal
pulses, this DTC will set.  (Symptom Code B)
If the ECM receives a certain amount of injection pump
CMP sensor signal pulses without a CKP sensor
signal, this DTC will set.  (Symptom Code D)

Condition for Running the DTC
Symptom Code B

• The ignition switch is ON.
• The engine speed is higher than 665 RPM.

Symptom Code D

• DTC P0335 (Symptom Code B) is not set.
• The ignition switch is ON.
• The fuel injection pump CMP sensor signal is

generated.

• The controller area network (CAN) communication

between the ECM and PCU is normal.

Condition for Setting the DTC
Symptom Code B

• The ECM detects extra or missing CKP sensor

signals while engine is running.

Symptom Code D

• The ECM detects that the CKP sensor signals are

not generated when doubled fuel injection pump
rotation speed is higher than 50 RPM.

Action Taken When the DTC Sets

• The ECM illuminates the malfunction indicator

lamp (MIL) when the diagnostic runs and fails.
The ECM uses an engine speed substitution of
doubled fuel injection pump speed for engine
control.

Condition for Clearing the MIL/DTC

• The ECM turns OFF the MIL when the diagnostic

runs and does not fail.

• A history DTC clears after 40 consecutive driving

cycles without a fault.  Or clear with the Tech 2.

Diagnostic Aids

• If an intermittent condition is suspected, refer to

Intermittent Conditions in this section.

• Ensure the sensor is tight and the flywheel

circumference is not damaged.

DTC P0335 (Symptom Code B, D) (Flash Code 43)
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

No

1

Did you perform the Diagnostic System Check –
Engine Controls?

—

Go to Step 2

Go to Diagnostic 

System Check – 

Engine Controls

2

1.

Install the Tech 2.

2.

Turn OFF the ignition for 30 seconds.

3.

Start the engine (Note a slight start delay may
be noticed).

4.

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

Does the DTC fail this ignition?

—

Go to Step 3

Go to Diagnostic 

Aids

3

1.

Turn OFF the ignition.

2.

Disconnect the crankshaft position (CKP)
sensor harness connector.

3.

Connect a DMM across the CKP sensor
terminals (pins 1 and 2 of J-183 connector).

4.

Measure the resistance across the CKP
sensor.

Is the CKP sensor resistance within the specified
value?

870 – 930 

Ω

Go to Step 4

Go to Step 20

6E-104    Engine Control System (4JH1) 

4

1.

Connect a DMM across the CKP sensor
terminals (measure the sensor output
voltage).

2.

Place the DMM on the AC volt scale.

3.

Start the engine.

4.

Monitor the DMM while accelerating the
engine between idle and W.O.T.  (accelerator
pedal full travel).

Does the DMM indicate an AC voltage increase in
accordance with an engine speed increase (the
range of approximately 1.4 volts is indicated from
approximately 0.7 volts)?

—

Go to Step 5

Go to Step 19

5

1.

Turn ON the ignition, with the engine OFF.

2.

Connect a test lamp between the low
reference circuit of the CKP sensor harness
(pin 1 of J-183 connector) and a known good
ground.

Does the test lamp illuminate?

—

Go to Step 11

Go to Step 6

6

1.

Keep the ignition switch ON, with the engine
OFF.

2.

Connect a test lamp between the low
reference circuit of the CKP sensor harness
(pin 1 of J-183 connector) and battery voltage.

Does the test lamp illuminate?

—

Go to Step 7

Go to Step 12

7

1.

Keep the ignition switch ON, with the engine
OFF.

2.

Connect a test lamp between the shield
ground circuit of the CKP sensor harness (pin
3 of J-183 connector) and a known good
ground.

Does the test lamp illuminate?

—

Go to Step 13

Go to Step 8

8

1.

Keep the ignition switch ON, with the engine
OFF.

2.

Connect a test lamp between the shield
ground circuit of the CKP sensor harness (pin
1 of J-183 connector) and battery voltage.

Does the test lamp illuminate?

—

Go to Step 9

Go to Step 14

9

1.

Keep the ignition switch ON, with the engine
OFF.

2.

Connect a test lamp between the signal circuit
of the CKP sensor harness (pin 2 of J-183
connector) and battery voltage.

Does the test lamp illuminate?

—

Go to Step 15

Go to Step 10

10

1.

Keep the ignition switch ON, with the engine
OFF.

2.

Connect a DMM between the signal circuit of
the CKP sensor harness (pin 2 of J-183
connector) and a known good ground.

Is the DMM voltage more than the specified value?

1 volt

Go to Step 16

Go to Step 17

Step

Action

Value(s)

Yes

No

 Engine Control System (4JH1)    6E-105

11

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

1.

Test the low reference circuit of the CKP
sensor between the engine control module
(ECM) (pin 98 of B-233 connector) and the
CKP sensor (pin 1 of J-183 connector) for a
short to battery or ignition voltage.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 21

12

1.

Test the low reference circuit of the CKP
sensor between the ECM (pin 98 of B-233
connector) and the CKP sensor (pin 1 of J-183
connector) for an open circuit or high
resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 18

13

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

1.

Test the shield ground circuit of the CKP
sensor between the ECM (pin 101 of B-233
connector) and the CKP sensor (pin 3 of J-183
connector) for a short to battery or ignition
voltage.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 21

14

1.

Test the shield ground circuit of the CKP
sensor between the ECM (pin 101 of B-233
connector) and the CKP sensor (pin 3 of J-183
connector) for an open circuit or high
resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 18

15

1.

Test the signal circuit of the CKP sensor
between the ECM (pin 90 of B-233 connector)
and the CKP sensor (pin 2 of J-183 connector)
for the following conditions:

• A short to ground
• A short to the low reference circuit
• A short to the shield ground

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 21

Step

Action

Value(s)

Yes

No

6E-106    Engine Control System (4JH1) 

16

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

1.

Test the signal circuit of the CKP sensor
between the ECM (pin 90 of B-233 connector)
and the CKP sensor (pin 2 of J-183 connector)
for the following conditions:

• A short to battery or ignition voltage
• A short to any 5 volts reference

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 21

17

1.

Turn OFF the ignition.

2.

Inspect for an intermittent and for poor
connections at the harness connector of the
CKP sensor (pins 1, 2 and 3 of J-183
connector).

3.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 20

18

1.

Turn OFF the ignition.

2.

Disconnect the ECM harness connector.

3.

Inspect for an intermittent and for poor
connections on the CKP sensor circuits at the
harness connector of the ECM (pins 90, 98
and 101 of B-233 connector).

4.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 21

19

1.

Inspect the CKP sensor for tightness.
Retest if the sensor was loose.

2.

Remove the CKP sensor and check for
damage, metal particles on magnet and for
flywheel circumference damage.

Did you find and correct the condition?

—

Go to Step 22

Go to Step 20

20

Replace the CKP sensor.  Refer to Crankshaft
Position Sensor Replacement in this section.

Did you complete the replacement?

—

Go to Step 22

—

21

Important:
Replacement ECM must be programmed.

Replace the ECM.  Refer to Engine Control Module
(ECM) Replacement in this section.

Did you complete the replacement?

—

Go to Step 22

—

22

1.

Reconnect all previously disconnected
harness connector(s).

2.

Clear the DTCs with the Tech 2.

3.

Turn OFF the ignition for 30 seconds.

4.

Start the engine.

5.

Monitor the DTC Information with the Tech 2.

Did the DTC fail this ignition?

—

Go to Step 3

Go to Step 23

23

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

No