B1398

Code

Other B — Body

Driver Power Window One Touch Window Relay Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 31 EN: 44 RU: 36

AI status

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Page language: EN

Causes

Blown fuse or faulty relay for the driver power window circuit
Open or shorted wiring between BCM/relay and driver window switch or motor
Corroded or loose connector(s) at relay, switch, motor or BCM
Failed driver door switch (one‑touch switch)
Failed power window relay
Poor ground connection at door or chassis

Symptoms

One‑touch (auto up or auto down) for driver window does not work
Window may operate only while holding the switch or may not operate at all
Intermittent one‑touch operation
No relay click heard when using one‑touch function
DTC stored and one‑touch feature disabled while code is present
Related convenience features (auto up/anti‑pinch) may be inhibited

What to check

Read and record freeze frame and related DTCs with a scan tool; clear code and attempt to re‑set by repeating the symptom
Visual inspection: fuses, relay, connectors, wiring at door, door jamb, switch and BCM for damage or corrosion
Check for proper fuse and relay presence and seating; swap relay with identical known‑good relay where applicable
Operate window while listening for relay click and observing switch behavior
Measure battery voltage at fuse and relay input with key on/engine off (~12–14 V)
Backprobe switch and module connectors to verify control and status signals when the one‑touch is commanded

Signal parameters

Battery supply at fuse/relay: approx. 12–14 V with key on
Relay coil/drive: energizes to supply power or ground—should show switching between ~0 V (ground) and battery voltage when commanded
Switch output to motor: should present battery voltage in one direction and ground in the other when operated (one‑touch command should produce a momentary full‑time supply)
Ground continuity: chassis/door ground should be low resistance (typically
Module logic/control lines: many BCM inputs/outputs are low‑voltage logic (0 V and approx. 5 V) — confirm expected levels from manufacturer data

Diagnostic algorithm

Retrieve B1398 and any related codes. Note conditions (ignition state, driver door open/closed) and freeze frame data.
Reproduce symptom: attempt one‑touch up/down and listen for relay. Note whether window moves normally when holding switch.
Visually inspect and manipulate wiring at driver door hinge area while operating switch to look for opens/shorts or intermittent behavior.
Check relevant fuses and the power window relay. Replace or swap relay with known‑good identical relay to test.
With a multimeter, verify battery voltage at the relay/fuse input. Backprobe relay output and motor connectors while commanding one‑touch to confirm correct switching voltage.
Backprobe the driver door switch: verify switch sends the expected control signal(s) on a one‑touch command (voltage change or logic signal).
Verify ground(s): measure continuity from switch/motor ground to chassis ground; repair any high resistance grounds.
Inspect and test the driver door switch assembly for internal faults; remove and bench‑test if necessary or substitute a known‑good switch.
If wiring and switch/relay are good, check BCM/power window module outputs with a diagnostic tool (output status, activation commands). Consult manufacturer service data for module test procedures.
Repair/replace failed components (wiring repair, connector replacement, relay, switch, or module) and clear codes. Retest several cycles of one‑touch and monitor for code return.
If intermittent or caused by wear/corrosion in the door harness, consider replacing or repairing the harness/connector and protecting against water intrusion.

Likely causes

Blown fuse or faulty power window relay
Corroded/loose connector at driver door switch or relay
Open or short in the harness to the driver door one‑touch switch
Failed driver door switch (one‑touch circuit)
Faulty BCM/power window control module

Fault status

⚠️ Status

Driver power window one‑touch relay circuit failure detected. One‑touch auto function may be disabled; check relay, fuse, wiring, switch and control module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours