This service bulletin provides information for dealers/technicians on OnStar Module 2G Sunset Information.
full bulletin at NHTSA ↗2005 Chevrolet Colorado electrical problems
severe 59 complaints filed with NHTSA · avg repair $850 · see electrical across all vehicles →
Failure mileage
Complaints
59
Recalls
0
Avg fix
$850
1crash
6fires
2injuries
When does it fail?
Of the 59 electrical complaints filed for the 2005 Chevrolet Colorado, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Of the 19 model years of Chevrolet Colorado we track for electrical problems, this one carries the most owner complaints on file — 59.
Owners have filed 59 electrical complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering electrical on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Preliminary Information communicates to the dealer the process for downloading or updating operating software for the Tire Pressure Monitor, Active Fuel Injector tester, multi media tester, PICO Scope, GR8 starting/charging tester and Vehicle Data Recorder tools, giving website address and step by step instructions to complete the update.
full bulletin at NHTSA ↗Vehicle Wide Programming (VWP) is a new process to update software on GM Vehicles. It provides the ability via a single selection within Techline Connect to first identify which modules need updating and then proceed to updating affected modules (with some exceptions). The updating of modules is completed in parallel instead of the technician needing to update one module at a time. This allows a more streamlined approach for dealers and customers.
full bulletin at NHTSA ↗This service bulletin provides information for dealers/technicians on Service Programming System (SPS) Error Codes E4398, E4399, E4401, E4403, M4404, M4413, M6954, M6955, E4414, E4423, E4491, E4492, or E6961 and resolution information.
full bulletin at NHTSA ↗The intent of this service bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2005 Chevrolet Colorado has a documented pattern of serious electrical failures that owners describe as recurring and potentially dangerous. The most pervasive defect is HVAC blower resistor and connector overheating, which melts plastic connectors and wires behind the glovebox, disabling fan speeds 1–3 while the highest setting remains active. Owners report burning smells and visible char marks—one owner had the heated connector singe a passenger's shin. GM continues installing identical replacement parts despite owners identifying the same defect after multiple repairs.
Passlock anti-theft system failures leave owners stranded, forcing 10–30 minute resets on average twice weekly for one owner over three years. Dealer diagnostic scanners cannot identify the fault when it's not actively occurring, and repairs cite ignition switch or body control module replacement at $1,100+. Window and door lock circuits drop out intermittently for up to a month before restoring themselves spontaneously. Alternator failure has triggered cascading electrical collapse, trapping owners inside vehicles unable to operate doors or windows.
Turn signal and brake light harnesses melt from inadequate wire gauge. One owner documented replacement twice, and another bypassed the HVAC resistor entirely after a second failure. An owner traced repeated failures to a corroded ground point on the passenger-side fender and resolved it by upgrading to heavier gauge wire. Multiple owners note stalling events at highway speeds with security lights illuminating, combined with engine startup refusals requiring multiple attempts. No recalls or technical service bulletins exist for these defects, though owners cite identical issues affecting GMC Canyon and Isuzu I-280 trucks.
Same Chevrolet Colorado electrical reports on nearby years: 2006 · 2007 · 2008
Failure modes owners describe
HVAC blower motor resistor and connector overheating/melting
The fan speed control resistor and wiring harness connector located behind/under the glovebox on the passenger side overheat and melt, disabling fan speeds 1-3 while speed 4 (high) remains functional. The melting plastic connectors and charred wires create a burning smell and fire hazard. Owners report replacing the same part multiple times with no resolution since GM continues to install identical, unre-engineered replacement parts.
When: Typically occurs between 50,000–170,000 miles; some failures noted within first 12 months of ownership
Symptoms owners cite: Blower fan only works on highest setting (speed 4) or on highest and lowest only; Burning smell from dashboard/HVAC area; Melted or charred connector pins and wires visible when inspected; Intermittent blower operation on lower speeds before complete failure; Smoke or fumes inside vehicle cabin near passenger feet/glovebox
Repairs/costs cited: Owners cite replacing resistor pack and connector harness; parts cost varies but labor at dealership described as high. GM offered one owner a $200 service certificate. Recurring failures noted; some owners bypassed the resistor entirely, leaving only high/off function. One owner replaced faulty ground wire with heavier gauge to resolve recurrence.
Recalls/TSBs owners mention: No recall issued as of complaint dates. GM told owners no service bulletin (TSB) exists. Dealership offered $200 service certificate to one owner but refused warranty coverage post-expiration. H3 Hummer reportedly recalled for identical defect.
Passlock anti-theft system intermittent failure
The passlock security system randomly fails to recognize the factory key, preventing engine start. When failure occurs, the vehicle requires a 10–15 minute wait for the system to automatically reset before the driver can attempt restart. The security warning light illuminates. Repeated failures occur on the same ignition cycle, forcing 20–30 minute waits on some occasions.
When: Failures occur intermittently over years of ownership; one owner reports 3+ years of recurring episodes occurring on average twice weekly
Symptoms owners cite: Security light illuminates on ignition turn; vehicle fails to crank; Engine cranks but immediately stalls after starting; Repeat start attempts fail; security system must reset (10–15 minute wait minimum); Failure occurs with original factory keys on multiple vehicles; Multiple consecutive failures in same session extend wait time to 20–30 minutes
Repairs/costs cited: Dealers cannot diagnose the intermittent fault when it is not actively occurring. One owner cited dealer estimate of $1,100+ for replacement of ignition and body control modules. Another owner paid $90 for dealer diagnostic scanner reset.
Recalls/TSBs owners mention: GM advised owners to bring vehicle to dealership when fault occurs, but dealers are often unable to replicate or diagnose. No recall or TSB issued for this defect on 2005 Colorado; identical issue reported on other GM vehicles with passlock systems.
Alternator failure and widespread electrical outages
Alternator failure triggers cascading electrical system failure, disabling windows, door locks, interior lights, radio, dashboard lights, and ignition function. Vehicle components activate randomly without keys in ignition (windshield wipers and interior lights). Burning smell reported. One owner trapped inside vehicle unable to open doors or lower windows.
When: Approximately 50,000 miles
Symptoms owners cite: Windshield wipers and interior lights activate on their own without keys in ignition; Vehicle fails to start or starts with difficulty; Power windows and door locks become inoperative; Radio and dashboard lights non-functional; Burning smell from engine compartment; Vehicle stalls and makes loud grinding noise; Owner unable to open driver door or lower windows; had to exit through window
Repairs/costs cited: Dealership diagnosed alternator failure requiring replacement; vehicle towed. Complete repair cost not provided.
Recalls/TSBs owners mention: None documented in narrative.
Electrical gremlins: random window/lock failure and instrument panel outages
Power windows (particularly driver-side) and door locks intermittently become inoperative for extended periods—sometimes up to a month—before system spontaneously restores function. Separate instances of instrument panel flickering, speedometer invisibility, and dashboard components cycling on/off. BCM (body control module) replacement mentioned by dealer in one case but not performed.
When: Multiple episodes over years of ownership; failures last up to one month each
Symptoms owners cite: Driver-side power window fails to operate; Door locks cease functioning; Instrument panel flickers or goes dark intermittently; Speedometer becomes invisible while driving; Vehicle fails to accelerate after complete stop; Dashboard lights cycle on and off; Clock, radio, dome light, and power window quit working randomly
Repairs/costs cited: Dealer quoted $200 for power window switch replacement. Instrument panel issues tied to possible BCM failure; one owner not pursued repair due to cost.
Recalls/TSBs owners mention: None documented. Multiple owners note GM acknowledges issue but provides no warranty coverage or recall.
Turn signal and brake light wiring harness degradation/melting
Wiring harnesses to front turn signals and brake light circuits melt and become inoperative due to inadequate wire gauge causing excessive heat buildup. Connector pins and wires burn, creating potential fire hazard. Multiple repeated failures noted on same vehicle.
When: Multiple failures across vehicle ownership
Symptoms owners cite: Turn signals cease functioning; melted wires and connectors visible; Brake lights inoperable; Burning/scorched smell from light circuits; Brake light indicator on dash illuminates; Burned connectors and excessive heat in harness; Turn signal relay failure preventing any signal operation
Repairs/costs cited: Owners replaced melted harnesses and connectors multiple times (one owner twice). One owner replaced entire connector loops.
Recalls/TSBs owners mention: None documented.
Brake light switch malfunction (post-recall replacement)
The replacement brake light switch installed under a previous brake light switch recall fails shortly after installation. Brake lights remain non-functional or appear to go out frequently. One owner initially did not realize the switch was the root cause, attributing failures to bulbs.
When: Failures occur shortly after recall replacement
Symptoms owners cite: Brake lights non-functional or appearing to go out repeatedly; Brake light indicator not activating lights; Switch fails to trigger brake light circuit
Repairs/costs cited: Dealer charged $137 for diagnostic test and $64 for replacement switch when repair was requested out-of-warranty.
Recalls/TSBs owners mention: Chevrolet refused warranty coverage post-warranty period, citing recall replacement had been performed. Owner reports GM said repair must be paid out-of-pocket.
Vehicle stalling and no-start conditions
Engine stalls sporadically and without warning while driving or immediately after starting. Vehicle is difficult to restart, requiring multiple ignition attempts or putting vehicle in neutral while moving. Security light illumination frequently precedes stalling. Ignition switch, body control module, and key/passlock sensor cited as potential causes but often unrepaired due to dealer inability to diagnose.
When: Occurs throughout vehicle ownership; one owner at 12,300 miles; another at 35,000 miles
Symptoms owners cite: Engine stalls without warning while driving (speeds 30–65 mph documented); Vehicle stalls immediately after starting; Security anti-theft light illuminates before/during stall; Requires multiple restart attempts; Requires placing vehicle in neutral and restarting while moving to avoid accident; Intermittent stalling over years of ownership
Codes mentioned: P0601 (CHECK SUM ERROR - computer glitch triggering 'reduced power' shutdown)
Repairs/costs cited: One owner had ignition switch replaced at dealer (12,300 miles); another at 35,000 miles. Multiple owners report dealers unable to diagnose when issue not actively occurring. Battery replacement attempted but stalling continued.
Recalls/TSBs owners mention: Dealers advise problem must occur on-site to diagnose; often unable to repair. GM has not issued recall.
Ungrounded electrical circuits creating fire hazards
Poor or corroded common grounding point on passenger-side fender wall creates insufficient ground return for multiple cabin electrical circuits (HVAC, lights, auxiliary power). This causes resistor packs and harnesses to overheat and melt, with cascading failures affecting brake lights, turn signals, hazard lights, aux plugs, and HVAC function. One owner traced the root to corroded ground connection and resolved by replacing factory ground with heavier gauge wire.
When: Multiple failures over vehicle ownership; one owner performed second replacement in one year
Symptoms owners cite: Burning smell from dashboard and cabin; Melted resistor and wiring harness in HVAC/blower circuits; Hazard lights, blinkers, and stop lights cease functioning; Dash lights intermittently fail; Auxiliary power plugs non-functional; Smoke/flames visible (one documented fire in cabin); Recurring failures after repeated repairs with identical parts
Repairs/costs cited: One owner replaced corroded ground connection with heavier gauge wire connected to vehicle frame behind stereo, which resolved recurring failures. Another replaced HVAC harness and resistor pack twice without solving root cause.
Recalls/TSBs owners mention: None documented. Owner noted GM is aware issue also affects GMC Canyon and Isuzu I-280 pickups.
ABS light and brake pedal loss of pressure (intermittent)
ABS warning light illuminates and brake pedal loses pressure, dropping nearly to the floor with minimal stopping ability. Brakes function normally after event and light extinguishes, but failure recurs unpredictably. Described as a potential 'bug' in ABS electronics causing false fault detection.
When: Intermittent occurrences without predictable duration or timing
Symptoms owners cite: ABS light illuminates; Brake pedal loses pressure and moves toward floor; Minimal braking power available during event; Audible whining from brakes during event; Brakes return to normal after ABS light resets; ABS light remains on until vehicle power cycle; Failure recurs unpredictably without warning
Repairs/costs cited: None documented; owner states dealer scanning shows no ABS faults.
Recalls/TSBs owners mention: None documented.
Engine stall with 'reduced power' limp mode and computer checksum error
Engine shuts down completely and displays 'REDUCED POWER' message on information display. Vehicle will not restart for a few minutes. Engine is killed rather than reduced to limp mode, creating unsafe traffic condition. Diagnostic code indicates computer checksum error (P0601).
When: At 102,000 miles; multiple recurrences
Symptoms owners cite: 'REDUCED POWER' message displays on instrument panel; Engine shuts down completely (not limp mode); Vehicle coasts to stop; Engine refuses to start for couple of minutes; Engine eventually restarts; Occurs multiple times since initial incident
Codes mentioned: P0601 (CHECKSUM ERROR)
Repairs/costs cited: None documented; described as poor programming.
Recalls/TSBs owners mention: None documented.
Door jamb wiring harness fatigue and breakage (rear door)
Wiring harness in rear door jamb of extended cab becomes fatigued and breaks, causing air bag warning light to illuminate continuously. Harness carries radio speaker, seat belt, and air bag circuits. Vehicle fails state inspection due to unresolved air bag light.
When: At 79,300 miles
Symptoms owners cite: Air bag warning light remains illuminated; Wiring harness in rear door jamb broken or fatigue-cracked; Unclear if air bag protection is active or system will malfunction
Repairs/costs cited: Dealer repaired by replacing extended cab driver-side rear door wiring harness.
Recalls/TSBs owners mention: None documented.
Instrument cluster display anomalies (language/unit switching)
Driver information center (DIC) on instrument cluster randomly switches from English to Spanish and from miles to kilometers without any user input. Dealership determined DIC module requires replacement. Repair cost exceeds $400.
When: Began at approximately 32,000 miles; reported at 36,500 miles
Symptoms owners cite: Display switches to Spanish language without user action; Mileage/speed units change from miles to kilometers; Occurs intermittently without pattern
Repairs/costs cited: Dealership quoted $400+ for DIC replacement. Initially offered coverage under speedometer settlement for other DIC defects, then denied.
Recalls/TSBs owners mention: Dealership denied speedometer settlement coverage.
Starter motor hangs (fails to disengage)
Starter motor continues running after engine has already started, creating grinding noise and potential damage. Fault occurs intermittently and is not reproducible at dealership.
When: At approximately 24,000 miles
Symptoms owners cite: Starter motor continues spinning after engine starts; Loud grinding noise from starter; Intermittent fault not reproducible during dealer test
Repairs/costs cited: Owner replaced starter motor; failure continued after replacement, indicating root cause elsewhere (likely ignition switch or BCM).
Recalls/TSBs owners mention: Dealership unable to diagnose or replicate fault.
Power loss and electrical shutdown ('Reduced Power/Traction Fault' limp mode)
Without warning, vehicle displays 'POWER REDUCED. TRACTION FAULT' message and all electrical systems shut down. Power steering becomes inoperative. Vehicle rolls to stop. Will not restart for several minutes. Cycle repeats multiple times in succession.
When: During highway drive; specific mileage not documented
Symptoms owners cite: 'POWER REDUCED. TRACTION FAULT' message; All electrical systems shut down; Power steering inoperative; Vehicle coasts to complete stop; Engine will not start for several minutes; Restarts briefly (~1 minute) then shuts down again; Cycle repeats multiple times during single drive
Repairs/costs cited: None documented; described as serious control loss.
Recalls/TSBs owners mention: None documented.
Turn signal stalk erratic behavior
Turn signal stalk operates unpredictably, activating wrong signal or failing to respond to input. Pushing stalk down for left turn produces no action or activates right signal instead.
When: Occurs intermittently while driving or at startup
Symptoms owners cite: Turn signal stalk unresponsive to downward input for left turn; Pushing stalk for right turn activates left signal instead; Intermittent failures; may work at next attempt; Occurs while driving or on startup
Repairs/costs cited: None documented.
Recalls/TSBs owners mention: None documented.
HVAC blower motor harness intermittent contact failure
HVAC blower motor wiring harness develops poor or intermittent contact at connector junction below glovebox. Manually jostling harness temporarily restores blower function at various speeds. Harness runs adjacent to glovebox and is prone to vibration-induced contact loss.
When: Intermittent; condition worsens over time
Symptoms owners cite: Blower motor fan speeds work intermittently; Manual jostling of harness below glovebox temporarily restores speeds; Blower cycles between off, partial speeds, and normal operation
Repairs/costs cited: Condition identified as faulty wiring harness contact.
Recalls/TSBs owners mention: None documented.
Synthesized from 59 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
Left power window, power door locks, clock radio, dome light quit working randomly. Dealer cannot duplicate problem. Onstar doesn't work sometimes. Battery seems to go dead if it sits more than 5 days, remote for door locks range is horrible but they say it's normal to have to stand right next to the truck to unlock / lock it. *jb
2005 Chevy colorado. Blower motor failure on lowest 3 of 4 fan settings. Did online research, learned common failure was resistor / connector (melting of wires and connector). Checked mine. It showed signs of overheating (grey plastic turned brown on one of the four pins. Bought new resistor and connector from gm dealer and self-installed. Blower now works on lowest and highest settings…
Had electrical trouble with your 2005 Chevrolet Colorado?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the electrical problem on the 2005 Chevrolet Colorado?
It's a meaningful issue. 59 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Across the 49 complaints that reported odometer mileage, most electrical failures cluster between 40,000 and 95,000 miles, with the median around 73,500. A quarter of owners report trouble before 40,000; a quarter make it past 95,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $850 for electrical repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to electrical?
No active recalls currently cover electrical issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2005/Chevrolet/Colorado.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.