Dodge Ram 2004, Service Manual

Page: 398 / 642

Symptom:
COOLDOWN TEST TOO COLD TO START
When Monitored and Set Condition:
COOLDOWN TEST TOO COLD TO START
When Monitored: When executing the Cooldown Test.
Set Condition: This message will be displayed if the A/C - Heater Control Module sees
evaporator temperature below 12.7°C (55°F) when executing the Cooldown 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
TEST ACTION APPLICABILITY
1 CAUTION: The work area ambient temperature must be above 21.1°C (70°F)
to test A/C system operation.
Start the engine.
Turn the A/C off.
Turn the blower on high. Allow the blower to run for 5 minutes to ensure that the
Evaporator Temperature Sensor temperature is above 12.7°C (55°F).
With the DRBIII
t
, actuate the Cooldown Test.
Does the DRBIII
t
display: Cooldown Test Too Cold To Start?
All
Yes
→
Go To 2
No
→
Perform additional testing as necessary.
Perform BODY VERIFICATION TEST - VER 1.
2 CAUTION: The work area ambient temperature must be above 21.1°C (70°F)
to test A/C system operation.
Turn the ignition on.
With the DRBIII
t
, read HVAC DTCs.
Does the DRBIII
t
display any HVAC DTCs?
All
Yes
→
Return to the symptom list and choose the symptom(s). After the
repair is complete, with the DRBIII
t
, erase the DTC(s). Cycle the
ignition switch. Start the engine. Set the blower control to high
speed. With the DRBIII
t
, actuate the Cooldown Test.
Perform BODY VERIFICATION TEST - VER 1.
No
→
Go To 3
384
HEATING & A/C