Honda CR-V car air conditioning can not Refrigeration

A mileage about 95000km, with the R20A1 2.0 L engine, semi-automatic air conditioning, 10 Dongfeng Honda CR-V. Reflects the owner: ecu チューニング car air-conditioning system is not cooling failure. It is understood that the car due to the failure in the other maintenance companies repaired, replace the air conditioning compressor electromagnetic clutch coil, but the fault is not ruled out. Take the car, the vehicle air-conditioning systems to carry out basic checks. Start the engine, turn on the air conditioner switch, air conditioning vent blowing natural wind. Open the engine compartment lid and found the air conditioning compressor does not work.


First connect refrigerant detectors, to detect the purity of the type of refrigerant and the refrigerant. The detection result is R134a in purity exceeding 99%. Normal; then the air conditioning pressure gauge group is connected to the air conditioning pipe, low pressure maintenance interface, read the high pressure gauge reading was 0.52 MPa, 車LEDライト the low pressure gauge reading of 0.50 MPa, air conditioning pipe pressure was normal. Observed after turning on the air conditioner switch to start the engine, the air conditioning compressor electromagnetic clutch still does not pull. PGM-FI system using HDS into read data stream, the engine throttle opening degree, the normal air pressure sensor data, but the air conditioning switch and the air conditioning compressor electromagnetic clutch data show a closed state, to prove ECM conditioning control unit does not receive the request to start the air conditioner The information of the operation of the compressor. Access to repair information that the need to activate the air conditioning compressor, air conditioning control unit through the air conditioning control unit 28-pin connector terminal 10, the air-conditioning compressor thermal protection switch to multi-channel controller outputs a high level signal. The multiple controller via CAN communication line air conditioning control unit air conditioning request information shared with ECM. Remove the air conditioning control unit plug wire side of the connector. Measurement of the connector terminals 10, the voltage on the 10.29 V, in the open air, when the air conditioning is turned off to 0V, which shows the air conditioning control unit is capable of outputting the request signal to start the air-conditioning compressor. The problem should appear in the air conditioning control unit to the line between the ECM.


To measuring air conditioning control unit wire side connector terminal leads for continuity between 10 to multiplexer controller wire side connector terminal F26 results conduction: Check the air conditioning compressor thermal protection switching performance measurement, normal; air conditioning compressor heat protect switch to the line between the 自動車パーツ air conditioning control single no normal conduction; Check the air conditioning compressor thermal protection switch to the continuity of the line between the multiple controller wire side connector terminals F26 results conduction: along main harness inspection found traces of changes in the main harness through the firewall part, through the investigation. Found that the owners after the installation of the alarm wiring harness from the main harness parts piercing and harness damaged.


Then peel the main wiring harness GM Tech2 inspection, it was found that there is a red wire snapped. The ultimate red wire repair after the test, the air conditioning compressor still does not work.