P2CA7: DC/DC Converter Temperature Sensor E Circuit High

What it means

The ECM detects a circuit high fault on the dc/dc converter temperature sensor e circuit. Reading cannot be used reliably for control.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Temperature sensor E monitors the DC/DC converter so the control module can account for its operating temperature. P2CA7 sets when the sensor E circuit signal is higher than the expected range, which may result from a signal short to power, an open sensor, or poor connector contact.

Common causes

Most likely first.

1. Signal wire shorted to B+
2. Open sensor
3. Connector pins corroded - high contact resistance

Symptoms

• Check-engine light or hybrid-system warning
• Reduced hybrid power or performance
• Hybrid-system temperature warning

How to diagnose it

1. Record freeze-frame data and review available converter temperature data and hybrid warnings to see when the high signal was detected.
2. With the vehicle powered down according to its service instructions, inspect sensor E's connector and wiring for damage or contact with a power feed.
3. Check connector terminals for corrosion, looseness, or poor contact.
4. Use vehicle wiring information to test the signal circuit for a short to power or an open connection.
5. Test sensor E against the manufacturer's specification to determine whether the sensor itself is open or the wiring is at fault.

Common fixes

• Clean and secure corroded or loose sensor E connector pins.
• Repair a signal wire shorted to power or an open in the circuit.
• Replace sensor E if testing confirms it is open or out of specification.
• Repair another confirmed fault in the sensor E circuit.

Can I keep driving?

The hybrid system may reduce power because it cannot rely on the DC/DC converter temperature reading. Avoid heavy loads and heed temperature warnings; stop somewhere safe if a warning persists or power drops.