P23CE: Fuel Heater Control Module Feedback Signal Circuit Range/Performance

What it means

Same as P23CD with feedback in plausible range yet not matching the commanded heater state.

At a glance

• Usually lights the check-engine light

How it works

The fuel heater control module reports heater status to the engine control module through a feedback circuit. P23CE sets when the feedback signal is electrically plausible but does not respond as expected to the commanded heater state.

Common causes

Most likely first.

1. Fault in the control module feedback circuit
2. Loose or corroded connector
3. Damaged feedback wiring
4. Fuel heater control module fault

Symptoms

• Check engine light
• Fuel or powertrain warning light, if equipped
• Hard starting or rough running in cold weather
• Reduced engine performance in cold conditions

How to diagnose it

1. Use freeze-frame data to note the heater command and operating conditions when the mismatch was recorded.
2. Compare the live heater command and feedback signal during a commanded change to see whether the feedback follows.
3. Inspect the feedback wiring and connectors for corrosion, loose pins, moisture, or damage that could cause an inconsistent signal.
4. Check feedback-circuit continuity and connections while gently moving the harness to reveal an intermittent fault.
5. If the wiring checks out, test the feedback circuit and fuel heater control module using the manufacturer's procedures.

Common fixes

• Reconnect a loose feedback-circuit connector.
• Clean or replace corroded connector terminals.
• Repair damaged or intermittent feedback wiring.
• Replace the fuel heater control module if testing confirms its feedback does not track the command.

Can I keep driving?

The mismatch can leave fuel heating uncertain, making cold starts or cold-weather running difficult and reducing performance in those conditions. If the engine runs normally in mild weather, driving may be possible, but address the fault before relying on the vehicle in cold conditions.