 |
This is a good waveform |
 View larger image
 Download this waveform file for use with PicoScope
Coolant Temperature Sensor Waveform Notes
The Coolant Temperature Sensor (CTS) will invariably be a two wire device with a voltage supply at approximately 5 volts. The sensor itself has the ability to alter its resistance with engine temperature change. The majority of sensors have a Negative Temperature Coefficient (NTC) which results in the resistance of the component decreasing as the temperature increases. The resistance change will therefore alter the voltage seen at the sensor and can be monitored for any discrepancies across its operational range.
By selecting a time scale of 500 seconds, connect the oscilloscope to the sensor and observe the output voltage. Start the engine and in the majority of cases the voltage will start in the region of 3 to 4 volts however this voltage will depend on the temperature of the engine, as the temperature increases the resistance decreases and the voltage will also be seen to drop. The rate of voltage change is usually linear with no sudden changes to the voltage, if the CTS displays a fault a certain temperature, this is the only true way of detecting it.
The Vauxhall Simtec system has a point at which the voltage alters dramatically during the warm up period, this is described in the notes section of the Coolant Temperature Sensor (Vauxhall) waveform page.
汽車診斷 | 汽車診斷儀 | 汽車故障診斷儀 | 汽車測試儀 | 汽車分析儀 | 汽車診斷示波器 | 汽車電路測試儀 | 汽車電路分析儀 | 發動機分析儀 | 發動機綜合分析儀 | 發動機檢測中心 | 點火分析儀 | 點火測試儀 | 汽車傳感器測試儀 | CAN總線示波器 | LIN總線示波器 | 汽車故障記錄儀 | 汽車傳感器分析儀 | 汽車檢測儀 | 噴油嘴測試儀 | 點火線圈測試儀 | 蓄電池測試儀 | 發電機測試儀 | 起動機測試儀 | ABS傳感器測試儀 | ECU測試儀 | ECM測試儀 | 進氣真空/壓力測試儀 | 排氣壓力測試儀 | 汽車技術培訓 | 爆震傳感器測試儀 | 缺火測試儀 | 缺缸測試儀 | 線路測試儀 | 引出線 | 汽車數字示波器 | 真空傳感器 | 高壓感應測試頭 | 無分電器點火測試頭 | 獨立點火（COP）感應測試頭 | 漏電測試儀 | 氣缸相對壓縮測試 | 電腦測試儀 | 發動機控制器測試儀 | 泄漏測試儀 | 熒光檢漏 | 超聲波檢漏 | 汽車數字萬用表 | 電流鉗表 | 電流勾表 | 點火正時燈 |
