Spectrum 3.0L GM - Page 107

107
DTC 105 MAT Short to High/Ground/Open
Step Action Value(s) Yes No
1
 Did you perform the On-board diagnostics
(OBD) system check?
NOTE: If the 5 volt reference supply 2 is shorted
to ground, various codes may set, including
Pedal 2, and 5 Volt Power Supply Codes, as well
as ignition system malfunctions. If multiple
codes are set, refer to diagnostics for code
524260 to verify 5 volt reference.
Go to Step
(2)
Perform OBD
System check
2
 Key ON.
 Monitor MAT PID.
Does Monitor display MAT at the default value of
214 degrees?
Go to Step
(3)
Intermittent
problem. Go
to Preliminary
and Intermit-
tent Checks.
3
 Key OFF.
 Disconnect the TMAP sensor connector J8
from the TMAP sensor.
 •Key ON, measure the voltage across pins 1
and 2
Is the voltage between 4.8 and 5.2 volts?
NOTE: Do not probe wires without proper ser-
vice tool. Permanent harness damage may
result
Between 4.8
and 5.2V
Go to Step
(4)
Go to Step
(5). If the 5
volt supply 2
is grounded,
an open code
will be set.
4
 Key OFF.
 Measure the resistance across the TMAP
sensor pins 1 and 2.
Is the resistance correct for the temperature as
shown in the temperature/ resistance chart
above?
Replace the
ECU. Go to
step last
Replace the
TMAP sen-
sor. Go to
step last
5
 Key OFF.
 Disconnect the ECU wire harness connector
ECU-B.
 Measure the resistance from TMAP sensor
connector C011 pin 2 and ECU-B pin E2.
 Measure the resistance from TMAP sensor
connector pin 1 and ECU-B pin H4.
Is the resistance less than 5?
<5
Go to Step
(6)
Repair the
circuit as ne-
cessary
6
 Disconnect the ECU wire harness connector.
 Measure the resistance between TMAP sen-
sor connector ground circuit pins 1 and 2.
Is the resistance greater than 30M?
>30M
Repair short
circuit as ne-
cessary
Go to Step
(7)