Damaged or corroded wheel speed sensor 2 (rear right) or its connector; Chafed, broken, or shorted wire in the sensor circuit, often near the wheel well or suspension components; Excessive air gap between the sensor and the tone ring due to debris, rust, or a loose sensor mount; Failed wheel speed sensor 2 due to internal electrical failure; Corroded or damaged tone ring (reluctor ring) causing a weak signal; Faulty ABS control module or PCM, though less common; Water intrusion or road salt contamination in the sensor connector

DTC codes / Chrysler codes / P1397

P1397 · ChryslerWheel Speed Sensor 2, G-Sensor Circuit Low Voltage

Q: What does code P1397 mean?

Wheel Speed Sensor 2, G-Sensor Circuit Low Voltage. P1397 on Chrysler vehicles indicates that the powertrain control module (PCM) has detected a low voltage condition on the signal circuit of wheel speed sensor 2, which is typically the rear right sensor on models with four-wheel anti-lock brakes. The PCM monitors the sensor's output and sets this code when the signal voltage falls below the expected threshold, often due to a wiring fault, poor connection, or a failing sensor.

P1397 on Chrysler vehicles indicates that the powertrain control module (PCM) has detected a low voltage condition on the signal circuit of wheel speed sensor 2, which is typically the rear right sensor on models with four-wheel anti-lock brakes. The PCM monitors the sensor's output and sets this code when the signal voltage falls below the expected threshold, often due to a wiring fault, poor connection, or a failing sensor.

SystemPowertrain

Code typeChrysler specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Anti-lock brake system (ABS) warning light illuminated on the dashboard
Traction control system (TCS) warning light may also be on if equipped
Speedometer may read erratically or stop working if the affected sensor provides the speed signal
ABS may be disabled, leading to potential wheel lockup during hard braking
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Damaged or corroded wheel speed sensor 2 (rear right) or its connector
Chafed, broken, or shorted wire in the sensor circuit, often near the wheel well or suspension components
Excessive air gap between the sensor and the tone ring due to debris, rust, or a loose sensor mount
Failed wheel speed sensor 2 due to internal electrical failure
Corroded or damaged tone ring (reluctor ring) causing a weak signal
Faulty ABS control module or PCM, though less common
Water intrusion or road salt contamination in the sensor connector

How to diagnose and fix it

Inspect the wheel speed sensor 2 connector and wiring for corrosion, damage, or loose pins; clean and repair as needed
Check the sensor's mounting and air gap; remove debris and ensure the sensor is seated properly
Measure the sensor's resistance and compare to specification; replace if out of range
Back-probe the sensor signal circuit at the ABS module connector and check for low voltage with the wheel spinning; repair wiring if voltage is low
Inspect the tone ring for cracks, missing teeth, or excessive rust; replace if damaged
If all wiring and sensor checks pass, test the ABS control module for proper operation and replace if faulty
Clear the code and perform a road test to verify the repair

Common Misdiagnoses for P1397

A low voltage code for wheel speed sensor 2 is frequently caused by a bad ground connection at the sensor or chassis, not a failed sensor itself, so always check grounds before replacing parts.
On many Chrysler models, the rear wheel speed sensor harness runs close to the exhaust and can suffer heat damage, leading to intermittent low voltage that only appears when the engine is warm.
The code may set due to a weak battery or charging system issue that causes overall low voltage, so verify battery and alternator performance before diving into sensor diagnostics.
After replacing a sensor, the code may persist if the new sensor's air gap is not correct; always use a feeler gauge to set the gap to specification.
A damaged tone ring can mimic a faulty sensor by producing a weak signal that the PCM interprets as low voltage, so inspect the ring carefully for cracks or missing segments.

Can I keep driving with P1397?

You can drive the vehicle with this code, but the ABS and traction control systems may be disabled, increasing stopping distances in slippery conditions. Avoid hard braking and have the fault diagnosed promptly to restore full safety system function.

Tools that help

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Guidance is general and written for Chrysler vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.