DTC 12: Vehicle Speed Signal System < A/T >: Diagnosis

WARNING: This page is about a different car, the 2005 Dodge Stratus and 2005 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tool:

MB991223: Harness Set

STEP 1. Check the speedometer.
Q: Does the speedometer work normally?

YES : Go to Step 2.

NO: Check the speedometer circuit and repair or replace as required. (Refer to COMBINATION METER ASSEMBLY AND VEHICLE SPEED SENSOR .)
STEP 2. Check auto-cruise control-ECU connector C-21 and joint connector (1) C-140 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?

YES : Go to Step 3.

NO: Repair or replace the faulty connector. (Refer to , HARNESS CONNECTOR INSPECTION ). Go to Step 4.

Fig 1: Checking Auto-Cruise Control-ECU Connector C-21
Courtesy of DAIMLERCHRYSLER CORPORATION

Fig 2: Checking Joint Connector C-140
Courtesy of DAIMLERCHRYSLER CORPORATION
STEP 3. Check the harness wire between auto-cruise control-ECU connector C-21 terminal 10 and joint connector (1) C-140 terminal 19 for damage.
Q: Is the harness wires in good condition?

YES : Check that DTC 12 is not set. If DTC 12 is not set, It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ). If DTC 12 is set, replace the auto-cruise control-ECU (Refer to AUTO-CRUISE CONTROL ), and then go to Step 4.

NO: Repair the damaged harness wire. Go to Step 4.

Fig 3: Checking Harness Wire Between Auto-Cruise Control-ECU Connector C-21
Courtesy of DAIMLERCHRYSLER CORPORATION

Fig 4: Checking Joint Connector C-140
Courtesy of DAIMLERCHRYSLER CORPORATION
STEP 4. Check the diagnostic trouble codes.
Q: Is DTC 12 set?

YES : Go to Step 1.

NO: This procedure is complete.