P1488
Auxiliary 5 Volt Supply Output Too Low.
- Dodge
- Powertrain
- Manufacturer code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 1
- Defined byThe manufacturer
- 4
- AreaAuxiliary emission controls
- 88
- FaultThe specific fault in that area
What it means
P1488 on a Dodge means the powertrain control module has detected that its auxiliary 5 volt supply output is too low. This supply feeds certain sensors, and the module saw the voltage fall below the expected range, so sensor readings may be unreliable. The exact sensors on this supply depend on the model and engine.
Symptoms
- Malfunction indicator lamp on
- Poor or erratic engine running
- Hesitation or reduced power
- Rough or unstable idle
- Other sensor-related fault codes stored at the same time
- Possible limp-home behaviour
Possible causes
- Short to ground or to another circuit in the wiring on the auxiliary 5 volt supply linelikely
- A faulty sensor drawing excess current and pulling the 5 volt supply downlikely
- Damaged, corroded or loose connectors on sensors sharing the supplypossible
- Chafed or rubbed-through harness near the engine, brackets or moving partspossible
- Poor power or ground supply to the powertrain control modulepossible
- Internal fault in the powertrain control modulerare
How to diagnose
- Read all stored and pending codes and note any other sensor supply or sensor circuit faults, then review the freeze frame data.
- Check the service information to identify which sensors share the auxiliary 5 volt supply on this model and engine.
- Visually inspect the wiring and connectors for those sensors, looking for chafing, water ingress, corrosion and bent or pushed-back pins.
- With the ignition on, measure the 5 volt supply at the affected sensor connectors and compare with the specification.
- Unplug the sensors on the supply one at a time and see whether the voltage recovers, which points to the faulty sensor.
- Test the supply wiring for shorts to ground or to other circuits with the module and sensors disconnected.
- Check the powertrain control module power feeds and grounds for voltage drop and good connection.
- If the wiring and sensors are all proven good, check for a module fault following the manufacturer's procedure.
How to fix
- Repair or replace any wiring shorted or damaged on the 5 volt supply circuit.
- Replace the sensor found to be pulling the supply voltage down.
- Clean or repair corroded connectors and terminals, replacing them where necessary.
- Repair poor power or ground connections to the powertrain control module.
- Replace or reprogram the powertrain control module only after all other causes are ruled out and the fault is confirmed.
Can I keep driving?
Medium severity
The car may be driveable, but sensor readings can be unreliable and it may go into limp-home mode, so get it checked soon. Avoid long journeys or heavy loads until it is fixed.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.