Isuzu 4JA1 Workshop Manual page 481

Step
5 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 test with the scan tool.
6. Command the Glow Relay ON with the scan tool
while observing the test lamp.
Does the test lamp turn ON only when commanded
ON with the scan tool?
6 Inspect the Glow (60A) slow blow fuse (SBF-8) in the
engine room fuse block.
Is the Glow (60A) slow blow fuse (SBF-8) open?
7 1. Turn OFF the ignition.
2. Remove the glow relay in the engine room relay
block.
3. Connect a test lamp between the voltage feed
circuit of the glow relay terminal (pin 4 of X-5
connector) and a known good ground.
4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate?
8 1. Turn ON the ignition, with the engine OFF.
2. Connect a test lamp between the power supply
circuit of glow plugs (pin 1 of X-5 connector) and
a known good ground.
Does the test lamp illuminate?
9 1. Turn OFF the ignition.
2. Inspect for
connections at the glow relay terminals (pins 1
and 4 of X-5 connector).
3. Repair the connection(s) as necessary.
Did you find and correct the condition?
10 1. Replace the Glow (60A) slow blow fuse (SBF-8).
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.
2. Repair the short to ground or replace the
component as necessary.
Did you complete the repair?
11 Repair the open circuit in the battery voltage supply
circuit between the Glow (60A) slow blow fuse (SBF-
8) and the glow relay (pin 1 of X-5 connector).
Did you complete the repair?
12 Repair the open circuit in the switched battery
voltage supply circuit between the glow relay (pin 1
of X-5 connector) and the glow plugs (E-49
terminal).
Did you complete the repair?
Action
an intermittent and for
Value(s)
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poor
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Engine Control System (4JH1) 6E-227
Yes
Go to Step 9
Go to Step 10
Go to Step 8
Go to Step 13
Go to Step 16
Go to Step 16
Go to Step 16
Go to Step 16
No
Go to Step 6
Go to Step 7
Go to Step 11
Go to Step 12
Go to Step 14
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