DTC 12

DTC 12: Vehicle Speed Sensor System








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

DTC SET CONDITIONS
The vehicle speed signals from the vehicle speed sensor 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 vehicle speed sensor.
- 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-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.







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 Use Trouble shooting/Inspection Service Points - How to Cope with Intermittent Malfunction). If DTC 12 is set, replace the auto-cruise control-ECU, and then go to step 4.
NO: Repair the damaged harness wire. Go to Step 4.

STEP4. Check the diagnostic trouble codes.

Q: Is DTC 12 set?

YES: Go to Step 1.
NO: This procedure is complete.