ATC - Poor/No Cooling From L/H or R/H Vents

ARTICLE NO.
00-6-5

DATE:
March 20,2000

SUBJECT:
AIR CONDITIONING - POOR OR NO A/C COOLING ON PASSENGER OR DRIVER VENT - VEHICLES WITH DUAL AUTOMATIC TEMPERATURE CONTROL (DATC)

LINCOLN:
2000 LS

ISSUE
Poor or no A/C cooling from the passenger or driver side vent on vehicles equipped with a Dual Automatic Temperature Control (DATC) system may occur on some vehicles. This may be caused by debris trapped in the coolant valve and/or the DATC module unable to control the coolant valve.

ACTION
Flush and/or replace the coolant valve and/or replace the DATC module. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Verify concern and determine if concern is with the coolant valve and/or DATC module.

2. Remove the RH cowl cover to gain access to the heater hoses.





3. Clamp off all three (3) heater hoses going into and out of heater core at the core (Figure 1).





4. Set the system to 60° F (15° C). If A/C cooling is restored, verify DATC module voltage and ground at the in-line connector (C134) (Figure 2), located on the upper radiator fan shroud.

CAUTION
DO NOT SHORT THE ENGINE COMPARTMENT WIRING HARNESS CONNECTOR C134 PINS 3 OR 6 TO PINS 1 OR 4. DAMAGE TO THE DATC MODULE CAN RESULT IF THIS OCCURS.





5. With the ignition key on in the Run position and the DATC set to 60° F (15° C), measure the voltage between engine compartment harness connector C134 Pin 4 and ground (Figure 3).

a. If voltage is less than 10 volts, repair Circuit 30-FB3.

b. If voltage is greater than 10 volts, check the DATC ground signal circuits.

6. Measure the voltage between the engine compartment harness connector C134 Pin 6 and the auxiliary junction box fuse terminal F124 (circuit 30-KA23) (Figure 3).

a. If voltage is less than 10 volts, replace the DATC module (XW4Z-19980-CA).

b. If the voltage is above 10 volts, measure the voltage between the engine harness connector C134 Pin 3 and the auxiliary junction box fuse terminal F124 (circuit 30-KA23).

c. If the voltage is below 10 volts, replace the DATC module (XW4Z-19980-CA).

d. If the voltage is above 10 volts, attempt the following:

(1) Set the DATC to maximum heat and run the engine at 2000 rpm for 5 minutes maximum.

(2) If A/C cooling is not restored, set the DATC to 60° F (15° C) and cycle the coolant valve by using in-line connector C134 (Figure 2).

(3) Rapidly disconnect and connect the in-line connector to cycle the valve. This should clear the valve within a few minutes. If A/C cooling is not restored, replace the coolant valve (XW4Z-18495-AA).

PART NUMBER PART NAME
XW4Z-18495-AA Coolant valve
XW4Z-19980-CA DATC Module

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME
000605A Replace Dual Automatic 0.5 Hr.
Temperature Control
(DATC) Module
000605B Replace Coolant Valve 2.1 Hrs.
3.9L Engine
000605C Replace Coolant Valve 1.7 Hrs.
3.OL Engine
000605D Perform Coolant Valve 0.3 Hr.
Flushing Procedure
000605E For Diagnostics, Use
Actual Time Per The
Warranty And Policy
Manual

DEALER CODING
CONDITION
BASIC PART NO. CODE
6010 49

OASIS CODES: 208000, 208200, 208999