Dodge Ram Truck 1500-2500-3500. Manual — part 793

P0113-INTAKE AIR TEMPERATURE SENSOR CIRCUIT HIGH (CONTINUED)

5.

(K900) SENSOR GROUND CIRCUIT OPEN

Measure the resistance of the (K900) Sensor ground circuit from the
IAT Sensor harness connector to the appropriate terminal of special
tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 6

No

>> Repair the open in the (K900) Sensor ground circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

6.

PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.

Were there any problems found?

Yes

>> Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Replace and program the Powertrain Control Module per Service Information.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

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P0116–ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT PERFORMANCE

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

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P0116–ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT PERFORMANCE (CONTINUED)

For the Engine System Schematic circuit diagram. (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

Theory of Operation

Engine Coolant Temperature Sensor performance looks at the outputs of three temperature sensors and compare
them under cold start conditions. Following a start to run delay time, the outputs of the ambient, engine coolant, and
intake air temperature sensors will be compared. If the intake air and ambient air temperature sensors agree and
the engine coolant temperature does not agree, the engine coolant temperature sensor is declared as irrational.

•

When Monitored:
Engine off time is greater than 480 minutes. Ambient temperature is greater than 4 deg C (38 deg F).

•

Set Condition:
After a calibrated amount of cool down time the PCM compares the ECT Sensor, IAT Sensor, and the Ambient
Air Temp Sensor values. If the ECT Sensor value is not within 10 deg C of the other two temperature sensors.
Two Trip Fault. Three good trips to turn off the MIL. (5.7L ETC lamp will illuminate with the MIL.)

Possible Causes

(K2) ECT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(K2) ECT SIGNAL CIRCUIT OPEN

(K900) SENSOR GROUND CIRCUIT OPEN

(K2) ECT SIGNAL CIRCUIT SHORTED TO GROUND

(K2) ECT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

ECT SENSOR

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).

Diagnostic Test

1.

ACTIVE DTC

Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes

>> Go To 2

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

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P0116–ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT PERFORMANCE (CONTINUED)

2.

(K2) ECT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Turn the ignition off.

Disconnect the C2 PCM harness connector.

Disconnect the ECT Sensor harness connector.

NOTE: Visually inspect both the component and the PCM connec-
tors. Look for damaged, partially broken wires, and backed out or
corroded terminals.
Ignition on, engine not running.

Measure the voltage on the (K2) ECT Signal circuit in the ECT Sensor
harness connector.

Is the voltage above 0 volts?

Yes

>> Repair the short to battery voltage in the (K2) ECT Signal

circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 3

3.

ECT SENSOR VOLTAGE ABOVE 4.6 VOLTS

Turn the ignition off.

Connect the C2 PCM harness connector.

Ignition on, engine not running.

With a scan tool, read the ECT voltage.

Is the voltage above 4.6 volts?

Yes

>> Go To 4

No

>> Go To 7

4.

ECT SENSOR

Connect a jumper wire between the (K2) ECT Signal circuit and the
(K900) Sensor ground circuit in the ECT Sensor harness connector.

With a scan tool, read the ECT voltage.

Is the voltage below 1.0 volt with the jumper wire installed?

Yes

>> Replace the ECT Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 5

NOTE: Remove the jumper wire before continuing.

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

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