Code
C0288
HUMMER
C — Chassis
Brake Warning Lamp Circuit Shorted to B+
Views:
UK: 16
EN: 20
RU: 14
AI status
Completed
Completed
100%
Causes
- Shorted lamp circuit (wiring pin or harness contacting B+)
- Corroded or damaged lamp socket/connector
- Faulty or stuck brake fluid level or parking brake switch supplying B+ to the circuit
- Failed instrument cluster / BCM / ABS module output driver
- Water intrusion or chafed wiring harness
- Aftermarket accessory tied into brake lamp circuit
Symptoms
- Brake warning lamp illuminated or stuck on
- Other dash warnings related to ABS/Brake/ESC may accompany
- Possible loss of ABS/traction control functionality or message
- Intermittent lamp behavior or codes that return after clearing
What to check
- Read stored codes and freeze frame data with a scan tool; note related codes (ABS, BCM, U-codes).
- Visual inspection of wiring, routing, and connectors for chafing, corrosion, or aftermarket taps.
- Inspect bulb or LED module and socket for corrosion, melted plastic, or signs of shorting.
- Check fuses and relays for instrument cluster/brake lamp circuits.
- Measure voltage at the lamp socket with key ON: verify presence or unexpected battery voltage.
- Disconnect connectors (cluster, module, lamp) to isolate harness vs module; see if code clears.
Signal parameters
- Battery voltage: ~12–14.5 V (normal reference).
- Expected brake lamp control circuit when lamp OFF: no continuous +12 V present to the control side (open/low).
- If shorted to B+: measured voltage on control circuit ≈ battery voltage (~12 V) even when lamp should be off.
- Continuity/Resistance: short to B+ will show very low resistance to battery positive; open circuit when properly disconnected.
- Lamp current (bulb): typical bulb current draw should be expected when lit; abnormal constant draw may indicate short.
Diagnostic algorithm
- Retrieve C0288 and any related codes with a scanner; record freeze frame and note when fault set.
- Perform a visual inspection of wiring from the brake lamp/cluster to the ABS/BCM for damage, moisture, or aftermarket splices.
- Inspect and, if equipped, remove the brake lamp bulb or cluster LED module. Check socket for corrosion; replace or clean as needed.
- With key ON (engine off), measure voltage at the lamp socket/control pin relative to ground. If ~battery voltage is present when lamp should be off, suspect short to B+.
- Disconnect the lamp/cluster/ABS module connector one at a time and clear codes after each step to isolate the circuit segment where the short disappears (helps locate upstream vs downstream).
- Backprobe and perform continuity tests between the circuit and battery positive and between the circuit and module output pin. Use an ohmmeter to find low resistance paths indicating short.
- Perform wiggle tests and flex wiring along harness while observing voltage or code status to find intermittent shorts.
- Repair or replace damaged wiring, connectors, sockets, switches, or lamp modules. Apply dielectric grease and secure harness away from heat/sharp edges.
- If harness and external components check good and short remains with module connected, test/replace the instrument cluster, BCM, or ABS module only after confirming internal fault with manufacturer service data/bench tests.
- After repair, clear codes, re-scan and perform a drive/operational cycle to verify the DTC does not return.
Likely causes
- Wiring short where harness rubs a chassis ground or power feed (most common)
- Bulb/socket or LED module has internal short or corrosion
- Connector at cluster or module contaminated or bent pins
- Faulty switch (parking brake or fluid level) feeding the lamp
- Defective instrument cluster/BCM/ABS module driver (less common)
Fault status
Status
Brake warning lamp circuit detected a short to battery positive (B+). The control module set C0288 when it measured unexpected +12V on the brake lamp/control circuit. May be stored as active or history and can be accompanied by ABS/BCM-related codes.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Repair manuals
Manual library for HUMMER
69
Browse 69 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email