The P1389 code is a specific code for Dodge vehicles (Stellantis group), related to the ASD (Auto Shutdown Relay) relay circuit. This relay is essential for supplying electricity to critical engine components, such as the injectors, ignition coil, or crankshaft sensor. Here is a complete guide to understanding and resolving this issue.
Meaning of Code P1389
The ASD relay acts as a safety switch controlled by the Powertrain Control Module (PCM). It cuts off the engine’s electrical power if anomalies are detected (e.g., absence of signal from the crankshaft sensor). Code P1389 is triggered when the PCM detects a malfunction in the ASD relay circuit, such as irregular voltage or a missing signal.
Possible Causes
- Faulty ASD Relay:
- Oxidized, stuck, or worn internal contacts.
- Electrical Issues:
- Blown fuse (often in the under-hood fuse box).
- Cut wires, short to ground, or corroded connectors.
- Crankshaft Sensor Failure (related to the ASD circuit):
- An incorrect signal from the sensor can disrupt the relay’s operation.
- PCM Failure (rare).
Common Symptoms
- 🚨 Engine light on (Check Engine message).
- 🔌 Engine stalling abruptly or not starting.
- ⚡ No spark or fuel injection (diagnosed via OBD2 scanner).
Diagnosis and Repairs
Verification Steps
- Check the ASD Fuse:
- Locate the fuse associated with the ASD relay (consult the Dodge manual). Replace it if blown.
- Test the ASD Relay:
- Swap it with an identical relay (e.g., headlight relay) to check its operation.
- Use a multimeter to test continuity and resistance (expected values: ~50-120 ohms).
- Inspect the Crankshaft Sensor:
- Check its connector and wiring. Test its resistance (typically 200-1000 ohms depending on the model).
- Check the Electrical Circuit:
- Look for exposed wires, melted insulation, or oxidized connectors between the PCM, ASD relay, and battery.
Common Solutions
- Replace the ASD Relay:
- Cost: €15 to €50. Choose a compatible part (e.g., Mopar or equivalent).
- Repair the Wiring:
- Use heat shrink tubing to insulate damaged wires.
- Replace the Crankshaft Sensor (if necessary).
Code Reset
- Use an OBD2 scanner to clear the P1389 code after repair. Perform a driving test to confirm resolution.
Affected Dodge Models
This code is common on Dodge vehicles equipped with 2.4L, 3.3L, 3.8L, or 5.7L HEMI engines, including:
- Dodge Grand Caravan
- Dodge Durango
- Dodge Ram 1500
- Dodge Charger/Challenger (certain years).
Safety Tips
- 🔋 Disconnect the battery before any electrical work to avoid short circuits.
- 🔧 Consult a repair manual specific to your Dodge model to accurately locate the ASD relay and crankshaft sensor.
When to Consult a Professional?
If the code persists after replacing the ASD relay and checking the circuit, a garage can:
- Diagnose a possible PCM failure.
- Analyze the crankshaft sensor signal in depth with an oscilloscope.
In summary: The P1389 code on Dodge indicates a problem with the ASD relay circuit, often resolved by replacing the relay or repairing the wiring. Prompt action prevents unpredictable engine failures. 🔧⚡