Cool Down Test Too Cold To Start

WARNING: This page is about a different car, the 2002 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

When Monitored:

When executing the Cool Down Test.

Set Condition:

This DTC will set if the A/C-Heater Control Module sees evaporator temperature less than 65°F (18.3°C) when executing the Cool Down Test.

Possible Causes:

Evaporator temperature too low.
Check for HVAC DTCs.
Check for PCM DTCs.
Evaporator Temperature Sensor.
Sensor Ground circuit high resistance.
Evaporator Temperature Sensor Signal circuit high resistance.
A/C-Heater Control Module.

CAUTION: Always turn ignition off before disconnecting or connecting any control module connector. Failure to do so could result in damage to control module.

NOTE: Ensure vehicle being tested has a fully charged battery. If it does not, false DTCs or error messages may occur.

NOTE: For component location, see appropriate illustration under COMPONENT LOCATIONS . For terminal identification, see appropriate illustration under CONNECTOR IDENTIFICATION . For circuit and wire color identification, see WIRING DIAGRAMS . For component removal and installation procedures, see appropriate component under REMOVAL & INSTALLATION .

NOTE: The work area ambient temperature must be more than 70°F (21.1°C) to test A/C system operation.

Testing:

Turn ignition off. Connect DRBIII(R) to DLC. Start the engine. Turn the A/C off. Turn the Blower to high speed. Allow the Blower to run for 5 minutes to ensure that the Evaporator Temperature Sensor temperature is more than 65°F (18.3°C). Using the DRBIII(R), actuate the Cool Down Test. Does the DRBIII(R) display COOL DOWN TEST TOO COLD TO START? If yes, go to next step. If no, perform additional testing as necessary. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Turn engine off. Turn ignition on. Using the DRBIII(R), read HVAC DTCs. Does the DRBIII(R) display any HVAC DTCs? If yes, return to DIAGNOSTIC TROUBLE CODE DEFINITIONS and perform appropriate DTC test. If no, go to next step.
Using the DRBIII(R), check for PCM DTCs. Are any PCM DTCs present? If yes, see SELF-DIAGNOSTICS - DAKOTA article in ENGINE PERFORMANCE. If no, go to next step.
Turn ignition off. Disconnect Evaporator Temperature Sensor harness connector. Turn ignition on. Using the DRBIII(R), select SENSOR DISPLAY, then read the Evaporator Temperature Sensor voltage. Is voltage more than 4.9 volts? If yes, go to next step. If no, go to step 6 .
Turn the ignition off. Connect a jumper wire across Evaporator Temperature Sensor harness connector terminals No. 1 and 2. Turn ignition on. Using the DRBIII(R), read the Evaporator Temperature Sensor voltage. Is voltage less than 0.1 volt? If yes, replace Evaporator Temperature Sensor. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, go to next step.

NOTE: Ensure the voltmeter leads are connected for positive polarity and that they meet the terminals in the Evaporator Temperature Sensor harness connector, and that there is good terminal-to-wire connection.

Turn ignition off. Reconnect Evaporator Temperature Sensor harness connector. Backprobe the Sensor Ground circuit between Evaporator Temperature Sensor harness connector terminal No. 1 and the A/C-Heater Control Module C1 harness connector terminal No. 3. Turn ignition on. Is voltage less than 0.1 volt? If yes, go to next step. If no, repair high resistance in the Sensor Ground circuit. After repair is complete, start the engine. Turn the Blower control to high speed. Using the DRBIII(R), actuate the Cool Down Test. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Turn ignition off. Backprobe the Evaporator Temperature Sensor Signal circuit between the Evaporator Temperature Sensor harness connector terminal No. 2 and the A/C-Heater Control Module C1 harness connector terminal No. 6. Turn the ignition on. Is voltage less than 0.1 volt? If yes, replace A/C-Heater Control Module. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, repair high resistance in the Sensor Signal circuit. After repair is complete, start the engine. Turn the Blower control to high speed. Using the DRBIII(R), actuate the Cool Down Test. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.