131
DTC 652 Injector Short/Open
Step Action Value(s) Yes No
1
Did you perform the On-board diagnostics
(OBD) system check?
Go to Step
(2)
Go to On-
Board Diag-
nostics
System
Check/Malfun
ction indicator
lamp.
2
For DTC 652-3 short to B+, Go to Step (3)
For DTC 652-5 Open Circuit, Go to Step (5)
For DTC 652-6 Short to Ground, Go to Step
(11)
3
Disconnect injector connector
Key OFF
Disconnect ECU-B
Measure voltage from injector pin 2 to
ground.
Is voltage greater than zero?
>0V
Go to Step
(4)
4
Key OFF, disconnect ECU-B
Key ON, measure voltage from pin 2 to
ground.
Is voltage greater than zero?
>0V
Repair short
to power in
the harness.
Go to
Step(14)
Replace
ECU. Go to
Step (14)
5
For affected cylinder, disconnect injector
connector, Key ON
Measure voltage from pin 1 to ground.
Is battery voltage present?
Battery Vol-
tage
Go to Step
(8)
Go to Step
(6)
6
With C008 disconnected, Key ON
Measure voltage at C007 pin 2
Is battery voltage present?
Battery Vol-
tage
Repair open
in harness
between
C008 and in-
jector
connector.
Go to Step
(14)
Go to Step
(7)
7
Key OFF, disconnect ECU-B.
Measure resistance from C008 pin 1 to ECU-
B pin A2
Is resistance less than 5?
<5
Refer to the
wiring dia-
gram for your
truck and re-
pair power
supply prob-
lem. Go to
Step (14)
Repair open
in the har-
ness. Go to
Step (14)
8
Measure resistance of affected injector.
Is resistance 2 ± .5?
2 ± .5
Go to Step
(9)
Replace in-
jector. Go to
Step (14)