P1545
DTC P1545: DOR Tampering Monitor (Temperature Change After Thermostat Open) [California]RADIATOR SENSOR CIRCUIT
Radiator Sensor Circuit (Part 1):
Radiator Sensor Circuit (Part 2):
CIRCUIT OPERATION
- The battery voltage is applied from the MFI relay to the radiator sensor (terminal No. 3), and it is grounded to the vehicle body from the radiator sensor (terminal No. 1).
- The radiator sensor (terminal No. 2) sends the sensor signal to the ECM (terminal No. 99).
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
DTC SET CONDITIONS
Logic Flow Chart:
Check Condition
- Battery positive voltage is higher than 11 volts.
- Intake air temperature is between 0 °C (32 °) to 40 °C (104 °F) when the engine is started.
- Engine coolant temperature is between 0 °C (32 °F) to 40 °C (104 °F) when the engine is started.
- The engine coolant temperature-intake air temperature is 5 °C (4 °F) or less when the engine is started.
- Engine coolant temperature is higher than 77 °C
Judgement Criteria
- When the output temperature of the radiator sensor after the thermostat valve is opened is rising by 6 °C (43 °F) or more in 1 second.
OBD-II DRIVE CYCLE PATTERN
Refer to MFI Diagnostic Function-OBD-II Drive Cycle-Pattern 19. OBD-II Drive Cycle
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
- Tampering of the DOR radiator
- ECM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A
STEP 1. DOR radiator sensor installation check.
- Check that the sensor is installed securely and operates normally.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Replace the DOR radiator. Then go to Step 3.
STEP 2. Replace the DOR radiator.
1. Replace the DOR radiator.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
2. Connect scan tool MB991958 to the data link connector.
3. Turn the ignition switch to the "ON" position.
4. Read the DTC.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P1545 set?
YES : Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID Code Registration Judgment Table [Vehicles with KOS] or ID Code Registration Judgment Table [Vehicles with WCM]. Then go to Step 3.
NO : It can be assumed that this malfunction is intermittent. Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points-How to Cope with Intermittent Malfunctions.
STEP 3. Perform the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to MFI Diagnostic Function-OBD-II Drive Cycle-Pattern 19. OBD-II Drive Cycle
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P1545 set?
YES : Repeat the troubleshooting.
NO : The procedure is complete.