P07C5

What it means

P07C5 means the transmission control unit has detected a low signal voltage in the circuit of intermediate shaft speed sensor A. The sensor monitors the speed of an internal transmission shaft, and the control unit compares it with other speed signals to manage shifting. The code sets when the signal sits below the expected range, which points to a short to ground, an open circuit, or a faulty sensor. Which transmissions use this sensor, and where it sits, depends on the model and transmission type.

Symptoms

• Warning light on, such as the engine management light or a transmission fault message
• Harsh, delayed or erratic gear changes
• Transmission stuck in one gear (limp mode)
• Speedometer or tachometer behaving oddly, on some models
• Loss of power or reduced acceleration
• Poor fuel economy because of limited gear selection

Possible causes

• Faulty intermediate shaft speed sensor A (internal failure or weak output)likely
• Damaged, chafed or oil-soaked wiring causing a short to ground or open circuit between the sensor and control unitlikely
• Corroded, loose or contaminated connector terminals at the sensor or transmission connectorlikely
• Fluid contamination or metallic debris on the sensor tip, or a damaged sensor mounting or tone ring/targetpossible
• Low or degraded transmission fluid affecting the sensor environment or internal componentspossible
• Fault in the transmission control unit or its sensor supply or groundrare
• Internal mechanical damage to the transmission shaft or its speed targetrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting vehicle speed, gear and temperature when the fault set, and check for related speed sensor codes
2. Check the transmission fluid level and condition (if a dipstick or check procedure applies), looking for burnt smell or metallic debris
3. Visually inspect the sensor, its wiring harness and connector for chafing, heat damage, fluid ingress, corrosion or bent pins
4. Wiggle-test the harness with live data displayed to see whether the intermediate shaft speed signal drops out or changes
5. With the connector disconnected, check the sensor supply, signal and ground circuits for continuity, shorts to ground and shorts to voltage, following the manufacturer's wiring diagram
6. Check the sensor's resistance or output against the manufacturer's specification for that model and transmission
7. Compare the intermediate shaft speed reading with input and output speed readings in live data to confirm which signal is wrong
8. Check for relevant technical service bulletins or calibration updates for the vehicle, then clear the code and road test to see whether it returns

How to fix

• Repair or replace damaged wiring, and restore any shorted or open circuit
• Clean, repair or replace corroded or damaged connector terminals and ensure the connector is fully seated and sealed
• Replace the intermediate shaft speed sensor A if it fails testing, and fit a new seal where applicable
• Correct the transmission fluid level or service the fluid as the manufacturer specifies, and clear any contamination found
• Repair the transmission control unit or its supply and ground circuits if testing proves it faulty
• Update the control unit calibration only if the manufacturer lists an outdated calibration as a known cause for this fault

Can I keep driving?

Nearby codes

• P07C4GenericInput/Turbine Shaft Speed Sensor C Circuit High
• P07C6GenericIntermediate Shaft Speed Sensor A Circuit High