B1742 – Front driver pressure side impact sensor (P-SIS) communication error (Kia)

Kia-specific code — factory diagnostic data

B1742 means the Kia EV6 airbag system may not “see” the front driver pressure side impact sensor, so crash protection can drop to a backup mode. In plain terms, you can lose some side-impact detection performance even though the car still drives normally. According to Kia factory diagnostic data, this code indicates a Front driver pressure side impact sensor (P-SIS) communication error. The AB (Airbag) module sets it when sensor messages stop, arrive corrupted, or fail internal validity checks. Treat this as a safety fault first. Diagnose the network, power, ground, and connector integrity before you replace any sensor.

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B1742 Quick Answer

B1742 on Kia vehicles points to a communication loss or communication fault between the AB (Airbag) module and the front driver pressure side impact sensor (P-SIS). Confirm power, ground, and the communication circuit at the sensor connector before condemning the sensor.

What Does B1742 Mean?

Official definition: “Front driver pressure side impact sensor (P-SIS) communication error.” The AB (Airbag) module logged a fault because it could not reliably communicate with that specific pressure-based side impact sensor. In practice, the SRS warning may turn on and the system may limit side-impact decision logic until communication returns.

What the module actually checks: the AB module expects periodic, correctly formatted sensor data and a stable electrical interface to that sensor. It monitors message timing, plausibility, and the electrical health of the communication path. Why it matters: the DTC points to a trouble area, not a failed part. A wiring fault, poor terminal fit, water intrusion, or a power/ground issue can interrupt data and trigger B1742.

Theory of Operation

On the Kia EV6, the AB (Airbag) module uses multiple inputs to judge side-impact severity and direction. The front driver pressure side impact sensor (P-SIS) supplies rapid pressure-change information from the vehicle structure. The module combines that data with other sensing inputs before it commands restraint devices.

B1742 sets when the AB module cannot maintain the expected communication with the front driver P-SIS. Intermittent opens, high resistance, or shorted circuits can distort the signal path. Low sensor supply voltage or a weak ground can also cause dropouts that look like “communication errors.” When the module loses confidence in that data stream, it stores the code and may illuminate the airbag warning.

Symptoms

You will usually notice a safety warning first, then scan-tool evidence of lost communication.

• Scan tool behavior AB (Airbag) shows B1742 and may display the front driver P-SIS as not responding or intermittent
• Airbag light SRS/airbag warning lamp illuminated
• Message cluster warning related to airbags/SRS (wording varies by Kia platform and market)
• Intermittent fault warning comes and goes after bumps, door slams, or temperature changes
• Stored history code logs as history after a low-voltage event or battery service
• No driveability change engine and braking feel normal, which can mislead diagnosis
• Additional SRS codes related communication or sensor supply DTCs may appear with B1742

Common Causes

• Loss of sensor power feed: A blown fuse, poor splice, or weak power distribution point can drop supply voltage and make the AB (Airbag) module lose communication with the front driver pressure side impact sensor.
• High-resistance sensor ground: Corrosion at a ground point or a loose fastener can pass a continuity test yet fail under load, which disrupts the sensor’s internal electronics and its data messaging.
• Open circuit in the P-SIS communication circuit: A broken conductor, backed-out terminal, or internal harness break stops message traffic and triggers a communication loss fault.
• Short to ground or short to power on the communication circuit: Chafed insulation or water intrusion can clamp the line low or drive it high, which prevents valid signal transitions and causes the AB module to flag a comm error.
• Connector issues at the P-SIS or AB module: Spread pins, poor terminal tension, or moisture in the connector creates intermittent contact that looks like an intermittent network dropout.
• Harness damage in the front/side body area: Impact damage, previous body repairs, or pinched routing can stress the sensor wiring and create intermittent opens that set B1742 on bumps or door/rocker flex.
• Incorrectly seated CPA/lock or secondary lock: A connector that “clicks” once may still sit partially unlatched, which causes momentary disconnects and repeat communication errors.
• Internal fault in the front driver pressure side impact sensor (P-SIS): If power, ground, and wiring integrity check good, the sensor may stop transmitting valid data and the AB module will log the communication error.
• AB (Airbag) module connection or internal fault: A poor module connector connection or an internal driver/receiver issue can mimic a sensor comm loss, so verify module powers and grounds before condemning any component.

Diagnosis Steps

Use a scan tool that can access Kia AB (Airbag) data and run a full network scan. Have a quality DVOM, back-probing tools, and wiring repair supplies. A test light or load tool helps load-check feeds. If the fault acts intermittent, use scan tool snapshots during a road test. Follow all SRS safety procedures before disconnecting connectors.

1. Confirm B1742 in the AB (Airbag) module and record freeze frame data. Focus on ignition state, battery voltage, vehicle speed, and any related SRS or communication DTCs. Freeze frame shows conditions when the code set. Use a snapshot later to capture live data during flex or road testing.
2. Run a full vehicle network scan and confirm the AB module appears and communicates. Note whether any other modules log communication faults. If multiple modules show network issues, diagnose the shared network or power distribution first.
3. Check for related SRS codes that point to power supply or internal AB faults. Clear codes, cycle the ignition, and see what returns immediately. A hard communication fault often resets on key-on if the AB module cannot see the sensor at all.
4. Check all SRS/AB-related fuses and power distribution points before probing the module. Do not trust a visual fuse check. Verify power on both sides of each fuse with ignition in the same state shown in freeze frame.
5. Verify AB module power and grounds with voltage-drop testing under load. Command any safe scan tool function that wakes the module, or use an approved load on the circuit. Measure ground drop while loaded and keep it below 0.1V. A weak ground can pass continuity tests and still break communication.
6. Inspect the front driver pressure side impact sensor (P-SIS) harness routing and both connectors. Look for pinched areas, abrasion, crushed sections, water tracks, and signs of prior body repair. Confirm the connector lock and any secondary lock fully seat.
7. With the system made safe per Kia SRS procedures, disconnect the P-SIS connector and inspect terminals closely. Check for spread terminals, pushed-back pins, corrosion, or moisture. Compare terminal tension by lightly drag-testing with the correct mating pin gauge if available.
8. Perform circuit integrity tests between the AB module and the P-SIS connector. Check for opens and shorts between conductors and to ground or power. Do not rely on continuity alone. Wiggle the harness while monitoring the meter to catch intermittent opens.
9. Restore connections and test the communication circuit behavior with ignition ON, because bias and signaling only exist when powered. Back-probe at a safe access point. Watch for an unstable or stuck bias condition that matches an open or short. If readings change when you flex the harness, isolate the exact location.
10. Use scan tool data to watch the sensor’s reported status, if available on the Kia EV6 platform. If the AB module shows the sensor as “not present,” “no signal,” or similar, focus on hard opens, power loss, or a failed sensor. If it shows intermittent dropouts, duplicate the issue with a snapshot during a controlled road test or harness flex test.
11. After repairs, clear codes and repeat the same ignition state and conditions that set the fault in freeze frame. Confirm the AB module maintains communication and B1742 stays cleared. Recheck for pending versus confirmed status after a complete drive cycle, since some monitors require repeat detection to confirm a fault.

Professional tip: Treat B1742 as a “suspected area” code, not a failed-part verdict. Prove the power and ground integrity first with voltage-drop under load. Then prove the harness and terminal fit with a wiggle test while watching live status. On the Kia EV6, most repeat com errors trace to connector tension or harness stress, not the sensor itself.

Possible Fixes

• Repair power feed or fuse supply issue: Restore correct AB/SRS power distribution, then confirm stable voltage under load and no repeat B1742.
• Clean, tighten, and validate ground points: Service the ground connection and confirm less than 0.1V drop while the circuit operates.
• Repair harness damage and secure routing: Fix opens/shorts, replace damaged sections, and protect the harness from future chafe or pinch points.
• Correct terminal fit or connector seating: Replace weak terminals, remove corrosion, and ensure secondary locks fully engage to stop intermittent disconnects.
• Replace the front driver pressure side impact sensor (P-SIS) only after circuit proof: Replace the sensor only when power, ground, and wiring tests prove good and communication still drops.
• Address AB (Airbag) module connection issues: Reseat the module connector, repair terminal issues, and verify module powers/grounds before considering module replacement.

Can I Still Drive With B1742?

You can usually drive the Kia EV6 normally with B1742, but you should treat it as a safety fault. This code comes from the AB (Airbag) module and points to a communication loss with the front driver pressure side impact sensor (P-SIS). When the AB module cannot reliably communicate with a side impact sensor, the SRS system may disable some airbag functions or change deployment strategy. Do not assume the airbags will work as designed in a side impact. Avoid carrying passengers until a qualified repair confirms full SRS operation.

How Serious Is This Code?

B1742 ranges from “inconvenience” to “high risk,” depending on what failed. If the fault comes from a brief low-voltage event or a loose connector that still makes contact, the symptom may seem intermittent. The risk stays high because SRS self-checks can disable coverage without warning. If the AB module sees a hard communication loss, treat the SRS system as potentially compromised. Diagnosis requires SRS-certified equipment, correct disabling procedures, and technician training. Do not probe SRS circuits casually or attempt DIY sensor replacement.

Common Misdiagnoses

Technicians often replace the pressure side impact sensor first because the code names it. That skips the real failure point on many Kia platforms: connector tension, water intrusion, or harness damage near the rocker, door opening, or A-pillar area. Another common miss involves power and ground quality. A weak 12-volt supply or poor ground can drop the AB module’s network thresholds and mimic “communication error.” Avoid wasted spending by confirming the scan tool’s module list, checking for related SRS/U-codes, verifying power/ground voltage drop under load, and inspecting connectors before any part order.

Most Likely Fix

The most common confirmed repair directions for B1742 on a Kia EV6 involve restoring reliable communication to the front driver P-SIS. Start with harness and connector correction. Focus on the sensor connector, intermediate couplers, and AB module connectors for corrosion, loose terminals, pin fit, and wiring damage. If tests prove the circuit and power/ground integrity, then suspect the P-SIS itself or an AB module network driver issue. Do not replace modules before you document good circuits and stable network behavior.

Repair Costs

Network and communication fault repairs vary by root cause — wiring/connectors are often the source, but module-level repairs or replacements can be significantly more expensive.

Last updated: April 9, 2026

Definition source: Kia factory description · Autel MaxiSys Ultra & EV. Diagnostic guidance is based on factory-defined fault logic for this code.