Dodge Nitro. Manual — part 697

With the ignition on.

Set Condition:

If the Evaporator Temperature Sensor input is out of range toward the high voltage threshold.

Diagnostic Test

1) ACTIVE DTC(S) PRESENT

Turn the ignition on.

Using the A/C Heater Control, turn the heater on.

With the scan tool, check for DTCs.

Does the scan tool display this DTC as active?

Yes

Go to 2).

No

The condition that caused this symptom is currently not present. Check for an intermittent
condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken
wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or
contaminated terminals. Repair as necessary.

Perform BODY VERIFICATION TEST - VER 1 .

2) CHECK (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A
SHORT TO VOLTAGE

Possible Causes

(C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT OPEN
(C121) SENSOR GROUND CIRCUIT OPEN
EVAPORATOR TEMPERATURE SENSOR
A/C HEATER CONTROL

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Electrical Diagnostics - Nitro

Fig. 4: Measuring Voltage Of (C21) Evaporator Temperature Sensor Signal Circuit In A/C Heater
Control C1 Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the A/C Heater Control C1 harness connector.

Turn the ignition on.

Measure the voltage of the (C21) Evaporator Temperature Sensor Signal circuit in the A/C Heater
Control C1 harness connector.

Is there any voltage present?

Yes

Repair the (C21) Evaporator Temperature Sensor Signal circuit for a short to voltage.

Perform BODY VERIFICATION TEST - VER 1 .

No

Go to 3).

3) CHECK (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT, (C121)
SENSOR GROUND CIRCUIT, & EVAPORATOR TEMPERATURE SENSOR

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Electrical Diagnostics - Nitro

Fig. 5: Measuring Resistance Between (C21) Evaporator Temperature Sensor Signal Circuit And
(C121) Sensor Ground Circuit In A/C Heater Control C1 Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Measure the resistance between the (C21) Evaporator Temperature Sensor Signal circuit and the (C121)
Sensor Ground circuit in the A/C Heater Control C1 harness connector. The approximate circuit
resistance should be as follows:



1468 ohms @ 40°C (104°F)



1800 ohms @ 35°C (95°F)



2221 ohms @ 30°C (86°F)



2757 ohms @ 25°C (77°F)



3443 ohms @ 20°C (68°F)



4330 ohms @ 15°C (59°F)



5485 ohms @ 10°C (50°F)



6998 ohms @ 5°C (41°F)



7354 ohms @ 4°C (39°F)



7731 ohms @ 3°C (37°F)



8130 ohms @ 2°C (36°F)



8553 ohms @ 1°C (34°F)



9000 ohms @ 0°C (32°F)

Is the resistance within the specifications?

Yes

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Electrical Diagnostics - Nitro

Replace the A/C Heater Control in accordance with the service information.

Perform BODY VERIFICATION TEST - VER 1 .

No

Go to 4).

4) CHECK (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR AN
OPEN

Fig. 6: Measuring Resistance Of (C21) Evaporator Temperature Sensor Signal Circuit Between
A/C Heater Control C1 Harness Connector And Evaporator Temperature Sensor Harness
Connector
Courtesy of CHRYSLER LLC

Disconnect the Evaporator Temperature Sensor harness connector.

Measure the resistance of the (C21) Evaporator Temperature Sensor Signal circuit between the A/C
Heater Control C1 harness connector and the Evaporator Temperature Sensor harness connector.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Electrical Diagnostics - Nitro