Honda HR-V Owners & Service Manuals

Honda HR-V: Description

COOLING FAN CONTROL SYSTEM DESCRIPTION - OVERVIEW

Overview

Receiving various signals, such as coolant temperature signals and refrigerant compression signals, from sensors, the PCM performs the fan control switching the fan speed (HI/LO) as needed. This control efficiently operates the radiator fan and A/C condenser fan, and improves fuel efficiency by reducing electrical load.

Fan LO Control Operation

In fan LO control, the PCM switches the FAN LO terminal to the ON position, and that switches the radiator fan relay to the ON position. Then, current flows from the 12 volt battery to the radiator fan relay, the radiator fan motor, the fan control relay and the A/C condenser fan motor, to create a series connection through the radiator fan motor and the A/C condenser fan motor. Using this series connection, the fan rotates at a lower speed.

Engine Cooling System - Testing & Troubleshooting

Fan HI Control Operation

In fan HI control, the PCM powers the FAN LO terminal and FAN HI terminal. This switches the radiator fan relay, the fan control relay, and the A/C condenser fan relay to the ON position. With the radiator fan relay and the fan control relay in the ON position, current from the 12 volt battery flows through the radiator fan relay to the radiator fan motor and then through the fan control relay to the ground. This rotates the radiator fan at a high speed. In addition, with the A/C condenser fan relay and the fan control relay in the ON position, current from the 12 volt battery flows through the A/C condenser fan relay to the A/C condenser fan motor to the ground.

This rotates the A/C condenser fan at a high speed.

Engine Cooling System - Testing & Troubleshooting

COOLING SYSTEM DESCRIPTION - COOLING CIRCUIT

Cooling System Description - Cooling Circuit

Overview

The coolant system uses a liquid cooling pressure circulation type, which is a bottom bypass system with a thermostat located at the water inlet side.

Cooling Circuit

Thermostat Closed:

Engine Cooling System - Testing & Troubleshooting

Thermostat Opened:

Engine Cooling System - Testing & Troubleshooting

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     Testing

    POWER RELAY TEST Special Tools Required Relay Puller 07AAC- 000A2A1 or 07AAC- 000A1A0 Relay Socket Extension (5 Pin) 07AGK- 000A2A0 Relay Socket Extension (4 Pin) 07AGK- 000A1A0 Test 1. Power Relay

     Check

    COOLANT CHECK Check 1. Coolant - Check Check the coolant level in the coolant reservoir. Make sure it is between the MAX mark (A) and the MIN mark (B) If the coolant level in the coolant reserv

     Symptom Troubleshooting

    BOTH THE RADIATOR FAN AND THE A/C CONDENSER FAN DO NOT RUN AT LOW SPEED Diagnostic Procedure 1. Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting Also check for Check the connectors are

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     AWD System Symptom Troubleshooting - Abnormal Noise (AWD)

    NOTE: If necessary, compare the noise with a known-good vehicle of the same type. If the noise is remarkably abnormal, do the following troubleshooting. 1. Problem verification (abnormal noise check) 1. Test drive the vehicle and check for the abnormal noise. Did the abnormal noise reappear? YES

     Advanced Diagnostics

    DTC ADVANCED DIAGNOSTICS: SRS RELATED DTCS NOTE Always check "How to troubleshoot the SRS system" and proceed along each "DTC Troubleshooting" procedure. Make sure the 12 volt battery is fully charged. If not, the results of tests may not be accurate. The SRS indicator will turn on when the

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