Isuzu KB P190. Manual - part 481

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-307

5

1.

Turn OFF the ignition.

2.

Remove the metal bus bar from the glow
plugs.

3.

Measure resistance of each glow plug
between the glow plug terminals and a known
good ground. Make sure to record all
measurements and take them quickly as to
not allow engine temperature changes
between measurements.

Are the resistances within the specified value each
other?

1

Ω

System OK

Go to Step 16

6

1.

Turn OFF the ignition.

2.

Replace the glow relay with the starter relay or
replace with a known good relay.

3.

Turn ON the ignition, with the engine OFF.

4.

Connect a test lamp between the metal bus
bar (glow plug power supply E-49 connector)
and a known good ground.

5.

Perform the Glow Relay Control with a scan
tool.

6.

Command the relay ON while observing the
test lamp.

Does the test lamp turn ON only when commanded
ON?

—

Go to Step 14

Go to Step 7

7

Inspect the Glow (60A) slow blow fuse in the
engine room fuse block.

Is the Glow (60A) slow blow fuse open?

—

Go to Step 8

Go to Step 9

8

Replace the Glow (60A) slow blow fuse. If the slow
blow fuse continues to open, repair the short to
ground on a circuit fed by the slow blow fuse or
check for a shorted attached component.

Did you complete the repair?

—

Go to Step 17

—

9

1.

Turn OFF the ignition.

2.

Remove the glow relay.

3.

Probe the battery voltage feed circuit of the
relay  (pin  4  of  X-5)  with  a  test  lamp  that  is
connected to a known good ground.

Does the test lamp illuminate?

—

Go to Step 10

Go to Step 11

10

1.

Probe the voltage supply circuit of glow plugs
(pin 1 of X-5) with a test lamp that is
connected to a known good ground.

2.

Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

—

Go to Step 13

Go to Step 12

11

Repair the open circuit or high resistance between
the Glow (60A) slow blow fuse and the glow relay
(pin 4 of X-5).

Did you complete the repair?

—

Go to Step 17

—

12

Repair the open circuit or high resistance between
the glow relay (pin 1 of X-5) and the glow plugs (E-
49 terminal).

Did you complete the repair?

—

Go to Step 17

—

Step

Action

Value(s)

Yes

No

6E-308   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

Circuit/ System Testing Glow Control System Check  (2 of 2)

13

Important: The glow plugs may be burnt out if the
battery voltage supply circuit is shorted to a voltage
source.
Repair the short to battery or ignition voltage
between the glow relay (pin 1 of X-5) and the glow
plugs (E-49 terminal).

Did you complete the repair?

—

Go to Step 17

—

14

1.

Remove the glow relay.

2.

Inspect for an intermittent and for poor
connection on each glow relay terminal.

3.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 17

Go to Step 15

15

Replace the glow relay.

Did you complete the replacement?

—

Go to Step 17

—

16

Replace the appropriate glow plug.

Did you complete the replacement?

—

Go to Step 17

—

17

1.

Reconnect all previously disconnected
components, relay, fuse or harness
connector(s).

2.

Turn OFF the ignition for 30 seconds.

3.

Turn ON the ignition, with the engine OFF.

4.

Connect a test lamp between the metal bus
bar (glow plug power supply E-49 connector)
and a known good ground.

5.

Perform the Glow Relay Control with a scan
tool.

6.

Command the relay ON while observing the
test lamp.

Does the test lamp turn ON only when commanded
ON?

—

Go to Step 5

Go to Step 2

Step

Action

Value(s)

Yes

No

Step

Action

Value(s)

Yes

No

1

1.

Turn OFF the ignition.

2.

Inspect the Meter (10A) fuse in cabin fuse
block.

Is the Meter (10A) fuse open?

—

Go to Step 2

Go to Step 3

2

Replace the Meter (10A) fuse. If the fuse continues
to open, repair the short to ground on one of the
circuits that is fed by the Meter (10A) fuse or
replace the shorted attached component.

Did you complete the repair?

—

Go to Step 14

—

3

1.

Turn OFF the ignition.

2.

Disconnect the ECM J-2 (C-58) harness
connector.

3.

Turn ON the ignition, with the engine OFF.

Is the glow indicator lamp OFF?

—

Go to Step 4

Go to Step 10

ENGINE CONTROL SYSTEM (4JK1/4JJ1)   6E-309

4

1.

Remove the Meter (10A) fuse that supplies
voltage to the glow indicator lamp.

2.

Turn ON the ignition, with the engine OFF.

3.

Measure the voltage from the glow indicator
lamp control circuit in the ECM harness
connector (pin 51 of C-58) to a known good
ground.

Is the voltage less than the specified value?

1 volt

Go to Step 5

Go to Step 11

5

1.

Turn OFF the ignition.

2.

Reinstall the Meter (10A) fuse.

3.

Turn ON the ignition, with the engine OFF.

4.

Connect a 3-amp fused jumper wire between
the ECM harness connector (pin 51 of C-58)
and a known good ground.

Is the glow indicator lamp illuminated?

—

Go to Step 9

Go to Step 6

6

1.

Turn OFF the ignition.

2.

Remove the IP cluster.

3.

Connect a test lamp between the ignition
voltage feed circuit of the IP cluster harness
connector (pin 8 of B-24) and a known good
ground.
Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

—

Go to Step 7

Go to Step 12

7

1.

Test the control circuit between the ECM (pin
51 of C-58) and the IP cluster (pin 35 of B-23)
for an open circuit or high resistance.

2.

Repair the circuit(s) as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 8

8

1.

Inspect for an intermittent and for poor
connections at the harness connector of the
IP cluster (pin 35 of B-23 and pin 8 of B-24).

2.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 13

9

1.

Inspect for an intermittent and for a poor
connection at the harness connector of the
ECM (pin 51 of C-58).

2.

Repair the connection(s) as necessary.

Did you find and correct the condition?

—

Go to Step 15

Go to Step 14

10

Repair the short to ground between the ECM (pin
51 of C-58) and the IP cluster (pin 35 or of B-23).

Did you complete the repair?

—

Go to Step 15

—

11

Repair the short to battery or ignition voltage
between the ECM (pin 51 of C-58) and the IP
cluster (pin 35 of B-23).

Did you complete the repair?

—

Go to Step 15

—

12

Repair the open circuit or high resistance on
ignition the voltage feed circuit the Meter (10A) fuse
and the IP cluster (pin 8 of B-24).

Did you complete the repair?

—

Go to Step 15

—

Step

Action

Value(s)

Yes

No

6E-310   ENGINE CONTROL SYSTEM (4JK1/4JJ1)

13

Repair or replace the IP cluster.

Did you complete the repair or replacement?

—

Go to Step 15

—

14

Important: Replacement ECM must be
programmed and learned.
Replace the ECM. Refer to ECM Replacement.

Did you complete the replacement?

—

Go to Step 15

—

15

1.

Reconnect all previously disconnected fuse or
harness connector(s).

2.

Perform the Glow Plug Lamp Control with a
scan tool.

3.

Command the lamp ON and OFF.

Does the glow indicator lamp turn ON and OFF
with each command?

—

Go to 1 of 2 Step 4

Go to Step 1

Step

Action

Value(s)

Yes

No