DTC Advanced Diagnostics: P00B3, P00B4 (3.0L Engine)

DTC P00B3: Engine Coolant Temperature (ECT) Sensor 2 Circuit Low Voltage DTC P00B4: Engine Coolant Temperature (ECT) Sensor 2 Circuit High Voltage

General Description

Courtesy of HONDA, U.S.A., INC.

Courtesy of HONDA, U.S.A., INC.

Engine coolant temperature (ECT) sensor 2 is a thermistor attached to the radiator. The powertrain control module (PCM) applies voltage (about 5 V) to the TW2_SENSOR signal circuit through a pull-up resistor. As the engine coolant temperature cools, ECT sensor 2 resistance increases, and the PCM detects a high signal voltage. As the engine coolant warms, the sensor resistance decreases, and the PCM detects a low signal voltage. If the ECT sensor 2 output voltage is excessively high or low, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	0.5 second or more
DTC Type	Two drive cycles, MIL on

Enable Conditions

Condition
Vehicle	ON mode

Malfunction Threshold

DTC: P00B3

The ECT sensor 2 output voltage [ECT Sensor 2 Voltage] is 0.174 V* 1 (0.012 V)* 2 or less for at least 0.5 second.

DTC: P00B4

The ECT sensor 2 output voltage [ECT Sensor 2 Voltage] is 4.93 V* 1 (4.987 V)* 2 or more for at least 0.5 second.

*1: USA and Canada models*2: Mexico models[ ]: HDS Parameter

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

DTC: P00B3

ECT sensor 2 TW2_SENSOR line short to ground

DTC: P00B4

ECT sensor 2 TW2_SENSOR line open
ECT sensor 2 TW2_SENSOR line short to power
ECT sensor 2 SG6 line open

Common

ECT sensor 2 failure
PCM internal circuit failure

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.

Conditions for clearing the DTC

The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.