P07C7

What it means

P07C7 is a generic code meaning the transmission control module has seen a low voltage or signal level in the circuit of intermediate shaft speed sensor B. The signal is below the expected range, which can point to a short to ground, an open circuit or a faulty sensor. The module cannot rely on the intermediate shaft speed, so it may restrict shifting to protect the transmission.

Symptoms

• Warning light on, such as the engine or transmission fault light
• Transmission in limp mode or fixed gear
• Harsh, delayed or erratic gear changes
• Speedometer or gear indicator behaving oddly on some vehicles
• Poor fuel economy or reduced performance
• Gearbox slipping or flaring between gears

Possible causes

• Faulty intermediate shaft speed sensor B (internal failure)likely
• Wiring shorted to ground or chafed insulation in the sensor circuitlikely
• Damaged, corroded or loose connector at the sensor or transmission control modulelikely
• Open circuit or high resistance in the signal or supply wirepossible
• Metal debris on the sensor tip or a damaged tone wheel or reluctor ringpossible
• Low or contaminated transmission fluid affecting the sensor or shiftingpossible
• Faulty transmission control modulerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting when the fault set and whether other speed sensor codes are present
2. Check the transmission fluid level and condition, as the correct procedure depends on the model and gearbox type
3. Inspect the sensor wiring and connector for chafing, fluid ingress, corrosion and pin damage
4. Check the sensor mounting and the sensor tip for debris, and inspect the tone wheel if accessible
5. Monitor live data for intermediate shaft speed against input and output speed while driving, if the vehicle supports it
6. With the connector unplugged, test the supply, signal and ground circuits for shorts to ground, open circuits and resistance using the manufacturer's wiring diagram
7. Measure the sensor resistance or output against the manufacturer's specification, as values vary by model
8. Check for software updates or technical bulletins for the model before suspecting the control module

How to fix

• Replace the intermediate shaft speed sensor B if it fails testing
• Repair or replace damaged wiring and ensure it is routed and secured properly
• Clean, repair or replace corroded or damaged connectors and terminals
• Clean debris from the sensor and correct any fluid contamination, including a fluid service if the manufacturer advises
• Repair or replace a damaged tone wheel, which may need the gearbox to be opened
• Update or replace the transmission control module only if testing confirms it is faulty or an update is a known fix

Can I keep driving?

Nearby codes

• P07C6GenericIntermediate Shaft Speed Sensor A Circuit High
• P07C8GenericIntermediate Shaft Speed Sensor B Circuit High