Jeep 1996 Grand Cherokee Service Manual - page 1096
(2) Test the resistance of the sensor with an input
impedance (digital) volt-ohmmeter. The resistance (as
measured across the sensor terminals) should be less
than 1340 ohms with the engine warm. Refer to the
previous
Coolant
Temperature
sensor/Intake Air
Temperature sensor resistance chart. Replace the
sensor if it is not within the range of resistance spec-
ified in the chart.
(3) Test the resistance of the wire harness. Do this
between the PCM wire harness connector A-15 and
the sensor connector terminal. Also check between
PCM connector A-4 to the sensor connector terminal.
Repair the wire harness as necessary if the resis-
tance is greater than 1 ohm.
VEHICLE SPEED SENSOR
To perform a complete test of the sensor and its
circuitry, refer to DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual.
THROTTLE POSITION SENSOR (TPS)—5.2L
ENGINE
To perform a complete test of the TPS and its cir-
cuitry, refer to the DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual. To test
the TPS only, refer to the following:
The TPS (Fig. 57) can be tested with a digital volt-
meter. The center electrical terminal of the TPS is
the output terminal.
With the ignition key in the ON position, check the
TPS output voltage at the center terminal wire of the
connector. Check this at idle (throttle plate closed)
and at wide open throttle (WOT). At idle, TPS output
voltage should must be greater than 200 millivolts.
At wide open throttle, TPS output voltage must be
less than 4.8 volts. The output voltage should
increase gradually as the throttle plate is slowly
opened from idle to WOT.
THROTTLE POSITION SENSOR (TPS)—4.0L
ENGINE
To perform a complete test of the TPS (Fig. 56) and
its circuitry, refer to the DRB scan tool and appropri-
ate Powertrain Diagnostics Procedures manual. To
test the TPS only, refer to the following:
The TPS can be tested with a digital voltmeter.
The center terminal of the TPS is the output termi-
nal.
With the ignition key in the ON position, check the
TPS output voltage at the center terminal wire of the
connector. Check this at idle (throttle plate closed)
and at wide open throttle (WOT). At idle, TPS output
voltage should must be greater than 200 millivolts.
At wide open throttle, TPS output voltage must be
less than 4.8 volts. The output voltage should
increase gradually as the throttle plate is slowly
opened from idle to WOT.
THROTTLE BODY MINIMUM AIR FLOW CHECK
PROCEDURE
5.2L ENGINE
The following test procedure has been developed to
check throttle body calibrations for correct idle condi-
tions. The procedure should be used to diagnose the
throttle body for conditions that may cause idle prob-
lems. This procedure should be used only after
normal diagnostic procedures have failed to
produce results that indicate a throttle body
related problem. Be sure to check for proper
operation of the idle air control motor before
performing this test.
Fig. 56 Intake Manifold Air Temperature Sensor—
4.0L Engine
Fig. 57 TPS—5.2L Engine
ZJ
FUEL SYSTEM
14 - 51
DIAGNOSIS AND TESTING (Continued)