P2705 code definition

For Ford and Chrysler makes, a P2705 trouble code indicates a malfunction in the transmission’s friction elements. The PCM has stored a trouble code and may show an illuminated malfunction indicator lamp (MIL) or Check Engine Light. Some vehicles might also be locked into “limp-in” mode.

P2705故障代码的意思是什么

A P2705 code is registered when the transmission’s output RPM signal is out of parameters, as compared to the input RPM signal, and the PCM reads it as a malfunction of transmission friction element. It’s not unlike a transmission component slippage code, which may accompany a P2705 code.

What causes a P2705 code

A P2705 code can be triggered by:

• Low transmission fluid level
• 变速箱流体泄漏
• 失败的传输泵
• Overheating engine
• Defective input or output speed sensors
• PCM故障
• Problems with wiring, connectors or other related electrical components

What are symptoms of a P2705 code?

• 苛刻的转移
• 延迟传输参与
• 传输滑移
• Illuminated MIL orCheck Engine Light
• “Limp-in” mode

机械师如何诊断P2705代码？

A tech can diagnose a P2705 code with a code reader that can access sensor codes, using that data to determine when the fault occurred. A road test might also be in order. It can be easy to misdiagnose a P2705 code, since a low fluid condition can quickly cause other problems due to overheating and damage to internal transmission components.

大多数配备OBD-II的车辆都有输入/涡轮速度传感器，可为PCM提供输入速度信号。该传感器通常直接螺纹到变速箱外壳中或螺栓固定在变速箱的外部。该霍尔效应传感器发送电压信号中断，PCM被读取为平方波形。传输移位点由输入和输出轴速度的比较确定。

How should a tech repair a P2705 code?

• A 3-wire connector is commonly used for this sensor, with one as a 5-volt reference signal, one as a ground wire and one as signal wire. Diagnosis should begin with a visual inspection forshorted, corroded, loose or damaged connections or wires。修理或根据需要更换，然后重新测试系统。

• Check for wiring or connectors that may be contaminated from engine oil, leaking transmission fluid, damage from road debris or burns from hot exhaust pipes. Problems like this can be read as an inconsistency between input and output speed sensor readings, and can be enough for the PCM to register them as a transmission friction element problem.

• 在修复此问题的同时，技术应该可以访问工厂接线示意图。修理后重新测试系统。如果所有接线，连接器，保险丝和其他组件都可以签出，请连接扫描仪以收集代码并诊断间歇性条件。清除代码，驾驶车辆，看看代码是否返回。如果不是这样，这可能是一个间歇性的问题，可能必须允许在正确诊断之前恶化。

• 与制造商规格相比，测试任何相关电路和传感器是否具有阻力和连续性。连接示波器并观察来自输入和输出速度传感器的实时传感器数据。观察O-Scope波形中的“软斑”，并更换所指示的任何组件。

• Repair any transmission leaks and refill with the right type of fluid. If the unit doesn’t overheat and seems to be working fine, a faulty input or output speed sensor is probably indicated. If the old fluid smells burnt or if the unit is leaking from behind the torque converter, at the front seal, the transmission will have to be dropped. At that point, it may just be best to consider a hard-parts rebuild.

• If everything else is eliminated, the PCM could be faulty – but PCM failure doesn’t happen often, and replacing the PCM will require reprogramming.

Additional notes on P2705 code

Sensor issues can be hard to track down, and often can mean several things. A methodical process-of-elimination method is key, rather than just replacing parts. One thing’s for sure, though – transmission problems only get worse as time and miles go on. A P2705 code and its symptoms mean that you should not keep driving that vehicle. Get it into a shop for qualified diagnosis and repair as soon as possible.

Need help with P2705 trouble code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle.获取报价并在线预约or speak to a service advisor at 1-800-701-6230.