Faulty ASD relay with worn or burnt contacts, or a failing coil inside it; Corroded, loose or heat-damaged connector or terminals at the ASD relay socket or in the power distribution centre; Open circuit or high resistance in the wiring between the relay output and the PCM sense input; Blown fuse in the ASD output circuit, caused by a short on a downstream load such as a coil, injector or sensor; Poor PCM power or earth connections, or low battery or charging voltage; Faulty PCM relay driver or sense input.

P1389

No Auto Shutdown (ASD) Relay Output Voltage At PCM.

Jeep
Powertrain
Manufacturer code
High severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
3: AreaIgnition system or misfire
89: FaultThe specific fault in that area

What it means

On a Jeep, P1389 means the powertrain control module (PCM) did not see battery voltage at its ASD relay output sense input when it commanded the Auto Shutdown relay on. The ASD relay normally feeds power to the ignition coils, injectors and, on many models, the heated oxygen sensors and other loads, so the PCM expects to see voltage there once the relay is energised. The exact circuit layout and fuse locations vary by model and engine.

Symptoms

Engine cranks but fails to start or starts then stalls
Intermittent stalling or misfire under load
Malfunction indicator lamp on
Hard or long cranking, particularly when hot
No spark or no injector pulse at times
Other codes stored for ignition, injector or oxygen sensor circuits

Possible causes

Faulty ASD relay with worn or burnt contacts, or a failing coil inside itlikely
Corroded, loose or heat-damaged connector or terminals at the ASD relay socket or in the power distribution centrelikely
Open circuit or high resistance in the wiring between the relay output and the PCM sense inputpossible
Blown fuse in the ASD output circuit, caused by a short on a downstream load such as a coil, injector or sensorpossible
Poor PCM power or earth connections, or low battery or charging voltagepossible
Faulty PCM relay driver or sense inputrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, including battery voltage and engine state when the code set
Check battery condition and charging voltage, and inspect battery terminals and main earths
Inspect the ASD relay, its socket and the power distribution centre for corrosion, heat damage and loose terminals
Check the fuses in the ASD output circuit using the wiring diagram for the specific model and engine, and look for the cause if any are blown
Swap the ASD relay with a known good relay of the same type, if the manufacturer's information allows, and retest
With a multimeter or scope, check for battery voltage at the relay supply, the relay control and the relay output when the relay is commanded on
Check continuity and resistance of the wiring from the relay output to the PCM sense pin, and inspect the PCM connector for pin damage or moisture
Only after all wiring and relay checks pass, check PCM power and earths and consider PCM fault using manufacturer procedures

How to fix

Replace the faulty ASD relay with the correct specification part
Clean or repair corroded or damaged relay socket terminals and connectors, or replace the affected connector
Repair or replace open, chafed or high-resistance wiring between the relay and the PCM
Find and repair the short that blew the fuse, then fit a new fuse of the correct rating
Restore battery, charging and earth connections to a sound condition
Replace or repair the PCM only if it is confirmed faulty, following manufacturer programming requirements

Can I keep driving?

High severity

Avoid driving the car, as the engine may stall without warning, which is unsafe in traffic, and it may fail to restart. Have it diagnosed before further use.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.