Pinpoint Test X: No Communication With The Rear Electronic Module (Rem)

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

Test Step

X1 CHECK CIRCUIT 29-DK31 (OG/BK) FOR VOLTAGE
- Key in OFF position.
- Disconnect the REM C420d.
- Key in ON position.
- Measure the voltage between the REM C420d-3, circuit 29-DK31 (OG/BK), harness side and ground.
  
  Fig 1: Checking Circuit 29-DK31 (OG/BK) Voltage
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Result / Action to Take
1. Yes : GO to X2.
2. No : REPAIR the supply circuit. TEST the system for normal operation.

X2 CHECK THE REM GROUND CIRCUITS FOR AN OPEN

Disconnect: REM C420b.
Disconnect: REM C420c.
Key in OFF position.

Using the following table, measure the resistance between the REM connector, harness side and ground:

REM CONNECTOR, HARNESS SIDE AND GROUND RESISTANCE

Pin	Circuit
C420b-12	31-DK30H (BK/OG)
C420c-11	31-DK30D (BK/OG)
C420c-12	31-DK30E (BK/OG)
C420c-25	31-DK30F (BK/OG)
C420c-26	31-DK30G (BK/OG)

Fig 2: Checking REM Ground Circuits For Open

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : Go To PINPOINT TEST K: THE REAR ELECTRONIC MODULE (REM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOL .
No : REPAIR the circuit in question. TEST the system for normal operation.