C0550 on Chevrolet
ECU Malfunction (Chassis)
C0550 on Chevrolet vehicles indicates ecu malfunction (chassis). Au7o has documented this code across 3 Chevrolet models — most commonly on HHR, Silverado 1500, Uplander. This is a chassis code indicating an internal Electronic Control Unit (ECU) malfunction, typically within the ABS/electronic brake control module or a related chassis controller. It sets when the module runs its internal self-checks (memory, processor, or output circuits) and detects a fault it cannot recover from. Because the affected controller often manages braking and stability functions, ABS, traction control, and stability control may be disabled, with their warning lights on. Base hydraulic braking generally still works. Typical repair costs on Chevrolet range from $250 to $1,200, depending on the specific model and root cause.
Common Causes of C0550
- •Internal failure of the ABS/EBCM control module
- •Low or unstable supply voltage / weak battery
- •Corroded or loose module power and ground connections
- •Software or memory corruption (may need reflash)
- •Damaged module connector or harness
- •Electrical interference or recent jump-start/voltage spike
C0550 on Chevrolet by Model
Chevrolet HHR(1 issue)
- Sudden Loss of Electric Power Steering (EPS) Assist2006-2011
The HHR's electric power steering motor can fail intermittently or completely, causing the steering to suddenly become very heavy while driving. Owners report the EPS shutting off under any condition, after which the wheel is extremely hard to turn until the engine is shut off and restarted to reset the system. GM recall 14V153 covered the 2009-2010 non-turbo cars and replaced the EPS motor, and a GM bulletin extended free EPS motor replacement (lifetime) to many 2006-2009 non-turbo HHRs; turbo models were excluded despite similar complaints.
Chevrolet Silverado 1500(1 issue)
- Transfer Case Encoder Motor / Position Sensor Failure Causing Stuck 4WD or Service 4WD Message2000-2013
Silverado 1500 trucks equipped with electronic shift transfer cases commonly develop failures in the transfer case encoder motor, mode position sensor, or related switch/module circuitry. Owners report the truck getting stuck in 2HI, 4HI, or 4LO, flashing selector lights, or displaying a Service 4WD message. GM service information and large numbers of owner complaints/forum reports document the issue across both GMT800 and GMT900 trucks.
Chevrolet Uplander(1 issue)
- Electric Power Steering Failure2005-2008
Electric power steering motor or control module fails causing loss of power assist. Steering becomes very heavy. GM issued recalls on some model years.
Looking for C0550 on a different make?
View C0550 across all makes →Frequently Asked Questions
What does C0550 mean on Chevrolet?▼
C0550 stands for "ECU Malfunction (Chassis)." This is a chassis code indicating an internal Electronic Control Unit (ECU) malfunction, typically within the ABS/electronic brake control module or a related chassis controller. It sets when the module runs its internal self-checks (memory, processor, or output circuits) and detects a fault it cannot recover from. Because the affected controller often manages braking and stability functions, ABS, traction control, and stability control may be disabled, with their warning lights on. Base hydraulic braking generally still works. On Chevrolet specifically, this code is documented across 3 models.
What causes C0550 on Chevrolet vehicles?▼
Common causes on Chevrolet: Internal failure of the ABS/EBCM control module, Low or unstable supply voltage / weak battery, Corroded or loose module power and ground connections, Software or memory corruption (may need reflash), Damaged module connector or harness. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix C0550 on a Chevrolet?▼
Repair costs on Chevrolet range from $250 to $1,200, depending on the specific model and root cause.
Which Chevrolet models have C0550 documented?▼
Au7o has documented C0550 on 3 Chevrolet models: HHR, Silverado 1500, Uplander.