Impco HHI, Service Manual

Page: 413 / 485

413
DTC 2123-FPP 1 Low Voltage
Step Action Value(s) Yes No
1
Did you perform the On-Board (OBD) System
Check?
-
Go to Step
(2)
Go to OBD
System
Check Sec-
tion
2

Key ON, Engine OFF

DST (Diagnostic Scan Tool) connected in
System Data Mode
Does the DST display FPP 1 voltage of 0.300
volts or less with the foot pedal in the idle posi-
tion?
0.300 volts
or less
Go to Step
(3)
Go to Step
(3)
3

Slowly increase FPP while observing the
FPP 1 voltage
Does the DST ever display FPP voltage below
0.300 volts?
Go to Step
(4)
Intermittent
problem
Go to Inter-
mittent
section
4

Disconnect the System Interface connector
CN21

Jump the FPP 1 circuit 153 and 5 volt refer-
ence circuit 119
Does the DST now show FPP 1 voltage above
0.300 volts?
Greater than
0.300 volts
Go to Step
(5)
Go to Step
(7)
5

Inspect FPP 1 and CN21 connectors for
damage corrosion or contamination
Did you find a problem?
Repair the
circuit as re-
quired. See
wiring har-
ness repair
section
Go to Step
(6)
6

Replace FPP 1 sensor
Is the replacement complete?
Go to Step
(12)
-
7

Key OFF

Disconnect ECM connector CN1

Using a DVOM check for continuity on the 5
volt reference circuit 119 between system in-
terface connector CN21 and ECM connector
CN1
Do you have continuity?
Go to Step
(8)
Repair the
open circuit
as required.
See wiring
harness re-
pair section
8

Using a DVOM check for continuity of the
FPP1 circuit 153 between ECM connector
CN1 and system interface connector CN21
Do you have continuity?
Go to Step
(9)
Repair the
open circuit
as required.
See wiring
harness re-
pair section