P1546

DTC P1546: DOR Radiator Tampering Monitor (Temperature Check at Cold Start)

RADIATOR SENSOR CIRCUIT

Refer to P1540.

CIRCUIT OPERATION

Refer to P1540.

MONITOR EXECUTION

- Once per driving cycle

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 temp from 0° C(32°F) to 40° C(104°F).
- Engine coolant temperature is less than 40° C(104°F) at engine start.
- The engine coolant temperature - intake air temperature is 5°C (41°F) or less at engine start.
Judgement Criteria

- When the difference between the radiator sensor output temperature after the engine is started and the coolant temperature is 15°C (59°F) or more.


OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 19 Monitors, Trips, Drive Cycles and Readiness Codes .

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)

- Tampering of the DOR radiator

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)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 19 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P1546 set?

YES Replace the PCM. Then go to Step 3.
NO The procedure is complete.
STEP 3. Perform the OBD-II drive cycle.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 19 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P1546 set?

YES Repeat the troubleshooting.
NO The procedure is complete.