Suzuki XL7 2007 Service Manual page 181

• After starting a cold engine, the ECT sensor
temperature should rise steadily, then stabilize after
the thermostat opens.
• High resistance in the circuits of either the ECT or IAT
sensor could set a DTC.
Reference Information
Schematic Reference
"Engine Controls Schematics"
Connector End View Reference
• "Engine Control Module Connector End Views"
• "Engine Controls Connector End Views"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
DTC Type Reference
"Powertrain Diagnostic Trouble Code (DTC) Type
Definitions"
Scan Tool Reference
• "Scan Tool Data List - Engine Controls - 3.6L (LY7)"
• "Scan Tool Data Definitions - Engine Controls - 3.6L
(LY7)"
• "Scan Tool Output Controls - Engine Controls - 3.6L
(LY7)"
Circuit/System Verification
Engine idling for 1 minute. Observe the DTC information
with a scan tool. DTCs P0117 and P0118 should not set.
Circuit/System Testing
1. Ignition OFF, disconnect the ECT sensor.
2. Ignition ON, verify that the ECT sensor parameter is
at −40°C (−40°F).
➢ If greater than the specified range, test the signal
circuit for a short to ground. If the circuit tests
normal, replace the ECM.
CAUTION
!
Do NOT use a test lamp to test the continuity
of the circuit. Damage to the control module
may occur due to excessive current draw.
NOTE
The control module or the sensor may be
damaged if the circuit is shorted to B+.
Engine General Information and Diagnosis:
3. Test for less than 1 volt between the low reference
circuit terminal 2 and ground.
➢ If greater than the specified value, test the low
reference circuit for a short to B+. If the circuit tests
normal, replace the ECM.
4. Ignition OFF, remove the fuse that supplies B+ to
circuit terminal C2-56 of the ECM.
5. Test for less than 5 ohms between the low reference
circuit terminal 2 and ground.
➢ If greater than the specified value, test the low
reference circuit for an open/high resistance. If the
circuit tests normal, replace the ECM.
6. Install the fuse that supplies B+ to circuit terminal
C2-56 of the ECM.
NOTE
If the fuse in the jumper wire opens, the
signal circuit is shorted to a voltage and the
sensor may be damaged.
7. Ignition ON, connect a 3A fused jumper wire
between the signal circuit terminal 1 and the low
reference circuit terminal 2. Verify the ECT sensor
parameter is greater than 142°C (288°F).
➢ If less than the specified value, test the signal
circuit for a short to voltage or an open/high
resistance. If the circuit tests normal, replace the
ECM.
8. If all circuits test normal, test or replace the ECT
sensor.
Component Testing
1. Ignition OFF, disconnect the harness connector of
the engine coolant temperature (ECT) sensor.
NOTE
A thermometer can be used to test the
sensor off the vehicle.
2. Test the ECT sensor by varying the sensor
temperature while monitoring the sensor resistance.
Compare the readings with the "Temperature Versus
Resistance - Engine Coolant Temperature Sensor"
table and verify that the resistance is within 5 percent
of the specification.
➢ If not within the specified range, replace the ECT
sensor.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Engine Coolant Temperature Sensor Replacement: "
• "Control Module References: " for engine control
module replacement, setup, and programming
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