Chrysler Concorde 2004 Service Manual page 264

HEATING & A/C
A/C CONTROL EBL SWITCH FAILURE (MANUAL A/C) —
TEST
4 Turn the ignition off.
Disconnect the Manual Temp Control Head C1 harness connector.
Disconnect the Body Control Module C1 harness connector.
Measure the resistance between the Sensor Ground circuit and the Mode Switch
MUX circuit in the Manual Temp Control Head C1 connector.
Is the resistance below 100.0 ohms?
Yes → Repair the Mode Switch MUX circuit for a short to the Sensor
→ Go To 5
No
5 If there are no possible causes remaining, view repair.
Repair
6 Press and release the Rear Defogger and the A/C select buttons on the control head
several times.
Does either of the buttons seem to stick at times?
Yes → Replace the Control Head.
→ Go To 7
No
7 Put the control switch in the Recirc/Bi-Level (full left) position.
Ensure the A/C and the Rear Defogger switches are off.
Turn the ignition on.
With the DRBIII , read the Mode Switch MUX voltage.
Is the voltage approximately 4.2 to 4.5 volts?
Yes → Go To 8
→ Replace the Control Head.
No
8 With the DRBIII , read the Mode Switch MUX voltage.
Press and hold the A/C button and observe the DRB voltage (should be approximately
0.45 volts).
Press and hold the Rear Defogger button and observe the DRB voltage (should be
approximately 0.25 volts).
Were the voltage readings correct when the switches were pressed?
Yes → There is no problem at this time with the Control Head Switches.
→ Replace the Control Head.
No
ACTION
Ground circuit.
Perform BODY VERIFICATION TEST - VER 1.
Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
Perform BODY VERIFICATION TEST - VER 1.
Perform BODY VERIFICATION TEST - VER 1.
Retry the system and recheck for DTC's.
Perform BODY VERIFICATION TEST - VER 1.
Perform BODY VERIFICATION TEST - VER 1.
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Continued
APPLICABILITY
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