B1623

Code

Other B — Body

Lamp Keypad Output Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 21 EN: 37 RU: 20

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Page language: EN

Perform visual inspection of keypad assembly, wiring harness and connectors for damage or corrosion
Check associated fuses and fusible links for continuity
Scan vehicle for related codes and freeze frame data
Operate keypad light on/off/dimmer while probing circuit to reproduce fault
Inspect for water intrusion or physical damage to keypad area
Check module ground and connector retention

Lamp output should switch between near 0 V (off) and battery voltage (~11–14 V) when commanded on in a 12 V system
When dimming is active the output may be a PWM signal — voltage average changes with duty cycle rather than steady intermediate voltage
Open-circuit: infinite resistance between module output and lamp return
Short-to-ground: near 0 V measured at lamp output when commanded on
Short-to-battery: battery voltage present at lamp output with no command

Retrieve stored codes and vehicle information; record freeze-frame and conditions when code set.
Perform visual inspection of keypad, harness, and module connectors. Repair any corrosion or damage.
Check relevant fuses and replace if blown. Re-check code presence.
With ignition/accessory power on, command keypad illumination on and measure voltage at keypad connector pin(s). Compare to expected (0 V off, ~battery voltage on).
If no voltage present, backprobe at control module output. If module output present but lamp not illuminated, check continuity from connector to lamp and measure resistance of lamp. Replace lamp assembly if open.
If output is stuck high (battery voltage with no command), inspect for short-to-battery or module fault. Disconnect keypad lamp connector: if code clears and module output returns to normal, suspect lamp/short in harness or keypad.
If output is 0 V when commanded on but module output commanded active, check ground and module supply voltage. If supply/ground okay and wiring intact, suspect module driver failure.
If intermittent, perform wiggle test on harness and connectors while monitoring voltage or using oscilloscope for PWM fluctuations. Repair wiring or connector as needed.
After repair, clear codes and verify operation over multiple ignition cycles and driving conditions; check for recurrence.
If all wiring and lamp checks are good and module output tests fail, consider module replacement or reprogramming per manufacturer procedures.