B1626

Code

Other B — Body

Lamp Keypad Output Short Circuit To Ground

Brand: Other

Type: B — Body

Views: UK: 22 EN: 57 RU: 26

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Page language: EN

Causes

Shorted wiring between the keypad/lamp output and ground
Failed lamp, LED module or keypad assembly with internal short
Damaged or chafed harness or connector pin contacting chassis ground
Faulty BCM or keypad control module output transistor
Corroded or loose connector creating a low-resistance path to ground
Aftermarket accessory or recent repair that disturbed the circuit

Symptoms

Keypad or push-button backlighting not working or overly dim
Blown fuses on related circuit
Intermittent or permanent inoperative lamps or keypad functions
Illumination that flickers or only works with certain ignition states
Possible multiple related circuits affected if BCM output is damaged

What to check

Retrieve freeze frame/OBD data and note when the fault sets (ignition state, conditions)
Inspect related fuses for open or signs of overheating
Visually inspect wiring, harness routing, connectors, and lamps/keypad for damage or corrosion
Disconnect the keypad/lamp connector and check if code clears or changes
Measure output voltage at the module connector with respect to ground (key on) and compare to expected
Measure continuity/resistance from output pin to chassis ground with harness disconnected to detect direct short

Signal parameters

Expected resting/low output: ~0 V
Expected active/high output (when driving lamp): approximately battery voltage (11–14 V)
Short-to-ground: near 0 V at output when it should be high; low resistance to chassis ground (typically < 5 Ω if a direct short)
Open-circuit: infinite/high resistance when module disconnected from load
Lamp/LED typical load: tens to hundreds of ohms depending on lamp type; excessive current draw indicates shorted device or wiring

Diagnostic algorithm

Read and record freeze frame and number of occurrences. Clear the code and operate the system to see if the code returns.
Inspect visible wiring, connectors and the keypad/lamp assembly for damage, corrosion, or signs of heat. Repair or replace damaged harness sections.
With ignition off, disconnect the keypad/lamp connector. Check resistance between the output pin and chassis ground. A very low resistance indicates a short in the lamp/connector/wiring.
With the connector disconnected, perform a bench check of the keypad/lamp assembly (if serviceable) using a fused 12 V supply or an equivalent test procedure to confirm internal short.
Reconnect and backprobe the BCM/module output pin with ignition on. Verify voltage changes when the lamp/keypad should be driven. If output remains at or near 0 V while the module commands ON, suspect a short or a failed module driver.
Inspect and test related fuses and fusible links for signs of overload. Replace only after locating and repairing the short.
If wiring and lamp assembly check good, consult manufacturer service information and consider module bench testing or replacement. Replace the BCM only after verifying wiring and loads are clean.
After repair, clear codes and re-test all related functions under the same conditions that produced the fault to confirm repair.

Likely causes

Wiring harness abrasion or pinched cable near hinge, dash, or console
Defective keypad or lamp assembly (internal shorted LED or driver)
Blown or low-resistance fuse or fusible link indicating high current
Faulty body control module output driver

Fault status

⚠️ Status

Lamp keypad output detected as shorted to ground. The body control module has logged a low-resistance path to chassis ground from the keypad/lamp output; related illumination or keypad functions may be inoperative.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours