P1496

What it means

On a Jeep, P1496 means the powertrain control module has detected that its regulated 5 volt reference supply, which powers several engine sensors, is too low. The module monitors this output and sets the code when the voltage drops below its expected range, usually because of a short, a faulty sensor pulling the supply down, or a fault in the module itself.

Symptoms

• Malfunction indicator lamp on
• Rough running or hesitation
• Poor throttle response or reduced power
• Engine stalling or hard starting
• Several sensor-related codes stored at the same time
• Erratic or unusual gauge and sensor readings

Possible causes

• A sensor on the shared 5 volt reference circuit has failed internally and is pulling the supply down (for example throttle position, accelerator pedal, MAP or camshaft or crankshaft position sensors, depending on model and engine)likely
• Wiring harness damage causing the 5 volt reference wire to short to ground or to another sensor circuit, such as chafed insulation or rubbed-through loomslikely
• Corroded, damaged or water-contaminated connector on one of the sensors or at the control modulepossible
• Poor or loose engine or module earth connections affecting reference voltagespossible
• Low or unstable battery or charging system voltage affecting the module's supplypossible
• Internal fault in the powertrain control module's 5 volt regulatorrare

How to diagnose

1. Read all stored and pending codes and note the freeze frame data; look for other sensor circuit codes that point to the shared reference circuit
2. Check the battery and charging voltage to rule out a low supply voltage
3. Visually inspect the engine harness and connectors for chafing, corrosion, water ingress, oil contamination or previous repairs
4. Use the wiring diagram for the specific model and engine to identify which sensors share the 5 volt reference
5. With the ignition on, measure the 5 volt reference voltage at the sensor connectors and at the module, comparing against the specification
6. Unplug the sensors on the shared circuit one at a time and watch whether the reference voltage recovers, which identifies the sensor pulling it down
7. Test the reference wire for short to ground and short to other circuits with the module disconnected, and check the engine and module earths for resistance
8. If wiring and sensors all test good and the voltage remains low, check for a relevant software update or have the module tested

How to fix

• Replace the sensor that is found to be pulling down the 5 volt reference
• Repair or replace the damaged wiring and secure the harness away from sources of chafing
• Clean, repair or replace corroded or damaged connectors and terminals
• Clean and tighten the engine and module earth connections
• Repair the charging or battery fault if the supply voltage is low
• Replace or repair the powertrain control module only after all other causes are ruled out, and follow the correct procedure for the vehicle

Can I keep driving?

This code for other makes

• P1496Dodge5 Volt Supply Output Too Low
• P1496KiaEGR Stepper Motor Malfunction Circuit 1 1.8L
• P1496Mitsubishi5 Volt Supply Output Too Low
• P1496Plymouth5 Volt Supply Output Too Low
• P1496Pontiac5 Volt Supply Output Too Low

Nearby codes

• P1495JeepLeak Detection Pump Solenoid Circuit Open Or Shorted
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