Pinpoint Test J: The Powertrain Control Module (Pcm) 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

J1 CHECK THE PCM C175 FOR DAMAGE

Key in OFF position.
Disconnect: PCM C175.
Inspect the PCM C175 for damage.
Is the PCM C175 OK?

Result / Action to Take

Yes

GO to J2.

REPAIR the PCM C175 as necessary. CARRY OUT the diagnostic tool data link test.

Test Step

J2 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) FOR AN OPEN BETWEEN THE DLC C251 AND THE PCM C175

Measure the resistance between the PCM C175 pin 16 circuit 914 (TN/OG), harness side and the C251 pin 2, circuit 914 (TN/OG), harness side.

Fig 1: Checking Circuit 914 (TN/OG) For An Open Between DLC C251 And PCM C175
Courtesy of FORD MOTOR CO.
Measure the resistance between the PCM C175 pin 15, circuit 915 (PK/LB), harness side and the C251 pin 10, circuit 915 (PK/LB), harness side.

Fig 2: Checking Circuit 915 (PK/LB) For An Open Between DLC C251 And PCM C175
Courtesy of FORD MOTOR CO.
Are the resistances less than 5 ohms?

Result / Action to Take

Yes

GO to J3.

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

Test Step

J3 CHECK FOR CORRECT PCM OPERATION

Disconnect all PCM connectors.
Check for:
- corrosion
- pushed-out pins
Connect all PCM 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 PCM. REFER to ELECTRONIC ENGINE CONTROLS . 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 self-test.