A/T

DTC 12: Vehicle Speed Signal System

Vehicle Speed Signal System Circuit:

CIRCUIT OPERATION
This circuit checks the vehicle speed signal. When the vehicle moves forward and reverses, the sensor turns ON and OFF repeatedly.

DTC SET CONDITIONS
The vehicle speed signals from the PCM are not input to the auto-cruise control-ECU when the vehicle speed is 40 km/h (25 mph) or more.

TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Malfunction of the output shaft speed sensor.
- Malfunction of the PCM.
- Damaged harness or connector.
- Malfunction of the auto-cruise control-ECU.

DIAGNOSIS

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 the harness wire between auto-cruise control-ECU connector C-107 terminal 10 and PCM connector C-116 terminal 80 for damage.

Q: Is the harness wire in good condition?

YES: Check that diagnostic trouble code 12 is not output. If diagnostic trouble code 12 is output, replace the auto-cruise control-ECU. Then check that diagnostic trouble code 12 is not output.

NO: Repair the harness wire and then check that diagnostic trouble code 12 is not output.