Jeep Wrangler 1997 Manual page 805

TJ
DIAGNOSIS AND TESTING (Continued)
(1) Disconnect wire harness connector from coolant
temperature sensor (Fig. 30) .
ENGINE
COOLANT
TEMPERATURE
SENSOR
i
ELECTRICAL
CONNECTOR,
Fig. 30 Engine Coolant Temperature Sensor-
Typical
(2) Test the resistance of the sensor with a high
input impedance (digital) volt-ohmmeter. The resis-
tance (as measured across the sensor terminals)
should be as shown in the Coolant Temperature Sen-
sor/Intake Air Temperature Sensor resistance chart.
Replace the sensor if it is not within the range of
resistance specified in the chart .
J928D-4
SENSOR RESISTANCE (OHMS}-COOLANT
TEMPERATURE SENSORIINTAKE AIR
TEMPERATURE SENSOR
(3) Test continuity of the wire harness between the
PCM wire harness connector and the coolant sensor
connector terminals . Refer to Group 8, Wiring for ter-
IDLE AIR CONTROL
PASSAGEINLET
MAP
SENSOR
FUEL SYSTEM
14- 33
minal/cavity locations . Repair the wire harness if an
open circuit is indicated .
IDLE AIR CONTROL (IAC) MOTOR
To perform a complete test of the IAC motor and
its circuitry, refer to DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual .
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
To perform a complete test of the intake manifold
air temperature sensor and its circuitry, refer to DRB
tester and appropriate Powertrain Diagnostics Proce-
dures manual . To test the sensor only, refer to the
following:
(1) Disconnect wire harness connector from intake
manifold air temperature sensor (Fig. 31) .
POWER STEERING PRESSURE SWITCH
INTAKE MANIFOLD
AIR TEMPERATURE
SENSOR
80524e3c
Fig . 31 Intake Manifold Air Temperature Sensor-
Typical
(2) Test resistance of sensor with an input imped-
ance (digital) volt-ohmmeter. The resistance (as mea-
sured across the sensor terminals) should be as
shown in the Coolant Temperature Sensor/Intake Air
Temperature Sensor resistance chart. Replace sensor
if it is not within range of resistance specified in
chart.
(3) Test resistance
of wire
harness .
Do this
between PCM wire harness connector A-15 and sen-
sor connector terminal. Also check between PCM con-
nector A-4 to sensor connector terminal. Repair wire
harness as necessary if resistance is greater than 1
ohm .
2.5L 4-Cylinder Engine Only
This switch (Fig. 32) provides an input to the Pow-
ertrain Control Module (PCM). The input is provided
during periods of high pump load and low engine
rpm ; such as during parking maneuvers . The PCM
will then increase idle speed through the Idle Air
TEMPERATURE RESISTANCE (OHMS)
C F
MIN MAX
-40 -40 291,490 381,710
-20 -4 85,850 108,390
-10 14 49,250 61,430
0 32 29,330 35,990
10 50 17,990
21,810
20 68 11,370
13,610
25 77 9,120
10,880
30 86
7,370 8,750
40 104 4,900 5,750
50 122 3,330 3,880
60 140 2,310 2,670
70
158 1,630 1,870
80 176 1,170 1,340
90 194
860 970
100 212
640 720
110 230 480 540
120 248 370 410