P0703
DIAGNOSTIC TROUBLE CODE PROCEDURESDTC P0703: Malfunction of Stoplight Switch
DIAGNOSTIC FUNCTION
TCM detects malfunction using the stoplight switch signal sent from the ETACS-ECU.
DESCRIPTIONS OF MONITOR METHODS
^ Drive the vehicle at 30 km/h (19 mph) or more for 10 seconds, and then turn the ignition switch to the "LOCK" (OFF) position. In this sequential operation, no variation has been found in the stoplight switch input signal in two consecutive times.
MONITOR EXECUTION
^ Continuous
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
^ Not applicable
Sensor (The sensor below is determined to be normal)
^ Not applicable
LOGIC FLOW CHARTS (Monitor Sequence)
Logic Flow Charts (Monitor Sequence):
DTC SET CONDITIONS
Check Conditions
^ Voltage of battery: 9 volts or more.
^ Voltage of battery: 16 volts or less.
Judgement Criteria
^ Stoplight switch signal fail [vehicle speed: 30 km/h (19 mph) for 10 seconds or more]: 2 count or more.
OBD-II DRIVE CYCLE PATTERN
All the conditions below continue for 6 seconds.
^ Transmission range switch: D
^ Vehicle speed: 10 km/h (6.2 mph) or more
^ Throttle position: 1/8 or more
^ Engine speed: 450 r/min or more
^ Transmission fluid temperature: 20°C (68°F) or more.
^ Transmission fluid temperature: 99°C (210°F) or more.
PROBABLE CAUSES
^ Malfunction of the CAN bus
^ Malfunction of the stoplight switch
^ Damaged wiring harness and connectors
^ Malfunction of TCM
^ Malfunction of ETACS-ECU
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to perform the CAN bus diagnosis.
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines.
STEP 2. M.U.T.-III data list
Item 50: Brake switch
OK: The service data changes in response to the brake operation.
Q: Is the check result normal?
YES: Intermittent malfunction
NO: Go to Step 3.
STEP 3. Check the following connector:
^ C-304 ETACS-ECU connector
^ C-312 ETACS-ECU connector
^ C-32 Stoplight switch connector
Check the contact status of the terminals.
Q: Is the check result normal?
YES: Go to Step 4.
NO: Repair the defective connector.
STEP 4. Stoplight Switch Check
Q: Is the check result normal?
YES: Go to Step 5.
NO: Replace the stoplight switch.
STEP 5. Check for open circuit in the wiring harness between the stoplight switch connector and the ETACS-ECU connector.
Between C-32 Stoplight switch connector (terminal No.2) and C-304 ETACS-ECU harness-side connector (terminal No.1)
Q: Is the check result normal?
YES: Go to Step 6.
NO: Repair the wiring harness.
STEP 6. Check for open circuit or short to ground in wiring harness between the ETACS-ECU connector and the joint connector (4)
Between C-312 ETACS-ECU harness-side connector (terminal No.16) and C-38 joint connector (4) (terminal No.10)
Q: Is the check result normal?
YES: Go to Step 7.
NO: Repair the wiring harness.
STEP 7. Check for open circuit in wiring harness between the stoplight switch connector and the joint connector (4)
Between C-32 stoplight switch connector (terminal No.1) and C-38 joint connector (4) (terminal No.10)
Q: Is the check result normal?
YES: Go to Step 8.
NO: Repair the wiring harness.
STEP 8. Symptom recheck after erasing diagnosis code
Q: Is the check result normal?
YES: Intermittent malfunction
NO: Replace the ETACS-ECU, and then go to Step 9.
STEP 9. Symptom recheck after erasing diagnosis code
Q: Is the check result normal?
YES: Intermittent malfunction
NO: Replace TCM.