Pinpoint Test E: The Electronic Automatic Temperature Control (EATC) Module Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2004 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

Test Step

E1 CHECK THE EATC MODULE C228b FOR DAMAGE

Key in OFF position.
Disconnect: EATC Module C228b.
Inspect the EATC module C228b for damage.
Is the EATC module C228b OK?

Result / Action to Take

Yes

GO to E2.

REPAIR the EATC module C228b. CARRY OUT the diagnostic tool data link test.

Test Step

E2 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) FOR AN OPEN BETWEEN THE DLC C251 AND THE EATC MODULE C228b

Measure the resistance between the EATC module C228b pin 12, circuit 914 (TN/OG), harness side and the DLC C251 pin 2, circuit 914 (TN/OG), harness side.

Fig 1: Checking Circuits 914 (TN/OG) For An Open Between DLC C251 And EATC Module C228b
Courtesy of FORD MOTOR CO.
Measure the resistance between the EATC module C228b pin 1, circuit 915 (PK/LB), harness side and the DLC C251 pin 10, circuit 915 (PK/LB), harness side.

Fig 2: Checking Circuits 915 (PK/LB) For An Open Between DLC C251 And EATC Module C228b
Courtesy of FORD MOTOR CO.
Is the resistance less than 5 ohms?

Result / Action to Take

Yes

GO to E3.

REPAIR the circuit in question. CARRY OUT the diagnostic tool data link test.

Test Step

E3 CHECK FOR CORRECT EATC MODULE OPERATION

Disconnect all the EATC module connectors.
Check for:
- corrosion
- pushed-out pins
Connect all the EATC module connectors and make sure they seat correctly.
Operate the system and verify the concern is still present.
Is the concern still present?

Result / Action to Take

Yes

INSTALL a new EATC module. REFER to CLIMATE CONTROL SYSTEM-GENERAL INFORMATION . CARRY OUT the diagnostic tool data link test.

The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the selftest.