Fault Code 1056 - Coolant Temperature Sensor Inactive

Disconnect wire harness connector from CTS. Using an ohmmeter, test resistance between sensor terminals.
With engine at operating temperature, resistance should be less than 1000 ohms. See TEMPERATURE SENSOR RESISTANCE VALUES table. Replace sensor if resistance is not within specification.
Using an ohmmeter, Check for continuity between ECU wire connector pin No. 15 and CTS connector terminal. Also, check resistance between pin No. 32 and CTS connector terminal. See Figure . Repair wire harness if an open is indicated.

Fig 1: ECU Connector Terminal Identification

Courtesy of CHRYSLER MOTORS.

TEMPERATURE SENSOR RESISTANCE VALUES

°F (°C)

⁽¹⁾ Ohms

212 (100)

160 (70)

450

100 (38)

1600

70 (20)

3400

40 (4)

7500

20 (-7)

13,500

0 (-18)

25,000

-40 (-40)

100,700

⁽¹⁾	Values given are approximate.

Fig 2: Coolant Temperature Sensor Circuit Diagram

Courtesy of CHRYSLER MOTORS.