B1548

Code

Other B — Body

Power Window Master Circuit Open

Brand: Other

Type: B — Body

Views: UK: 27 EN: 32 RU: 27

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Blown fuse or fusible link supplying the master switch
Open, broken, or disconnected wiring between the fuse, master switch, and body control module (BCM)
Corroded, bent, or poorly seated connector pins at the master switch or BCM
Failed/master switch internal open circuit
Faulty BCM or power window control module (less common)
Poor or missing ground for the power window circuit

Symptoms

Master window switch does not operate one or more windows
No response (dead) from driver door master switch while passenger switches may still work
Intermittent window operation that fails when door is moved or switch is wiggled
Possible loss of illumination for the master switch controls
DTC stored and related lamp or system message may be present

What to check

Read stored DTCs and freeze frame/fault data with a scan tool; confirm B1548 and any related codes
Visually inspect fuses and fusible links for the power window/master switch circuit
Inspect wiring and connectors at the driver door, master switch, and BCM for breaks, corrosion, or loose pins
Check for proper ground(s) at the driver door and master switch
Operate the switch while observing connectors for movement-related failures (wiggle test)

Signal parameters

Supply voltage to master switch with ignition ON: ~10–14 V (battery voltage range)
Switch-to-BCM circuit continuity: near 0 ohms for a good connection; open/infinite if circuit is open
Switch internal resistance when actuated: should change from open to closed depending on switch position (manufacturer-specific)
No output voltage on the control line when switch is open (expected idle) and appropriate voltage when actuated (varies by vehicle)

Diagnostic algorithm

Confirm the customer complaint and retrieve DTCs with a scan tool; record related codes and freeze/frame data
Perform a visual inspection of fuse(s) and fusible link(s) for the power window and replace if blown; recheck code
With ignition ON, measure battery voltage at the power feed pin of the master switch connector. If no voltage, trace back to fuse/ignition feed and repair
Check continuity between the master switch connector and the BCM pin for the same circuit. Repair any open circuits found (replace or splice wiring as required)
Inspect and clean both male and female connector terminals at the switch and BCM; repair or replace damaged connectors or pins
Backprobe the master switch while operating it and confirm expected voltage change on the control line. If the feed is present but no output from the switch, suspect the master switch assembly
If wiring and switch test good, check BCM outputs and inputs with a scan tool or lab scope per manufacturer procedures; perform a known-good switch substitution if available to isolate BCM vs switch
After repairs, clear DTCs, cycle ignition, and verify proper operation of windows from the master switch and that B1548 does not return
If intermittent, perform durability checks by cycling windows and moving the door and harness to reproduce fault and confirm repair

Likely causes

Blown or loose fuse feeding the master switch
Open wire or broken conductor in the harness to the master switch
Disconnected or corroded connector at the switch or BCM
Master switch internal connector or PCB failure

Fault status

⚠️ Status

Power Window Master Circuit Open — the control circuit for the driver (master) power window switch has an open (loss of continuity) condition preventing normal master switch operation.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5 - 1.5 hours