What Does B1288 Mean?
This code indicates the Body Control Module (BCM) or climate control module has detected a circuit malfunction in the potentiometer feedback signal from the right side air intake servo motor. The servo motor controls air distribution door positions within the HVAC system, and the potentiometer provides position feedback to the control module. The BCM has determined that the potentiometer signal is out of expected range, intermittent, or completely absent.
Common Causes
45%
Failed or worn potentiometer within the right air intake servo motor assembly
30%
Damaged wiring harness or corroded connector pins between BCM and servo motor
15%
Broken or stripped servo motor gears causing incorrect position feedback
10%
Failed Body Control Module or climate control module internal circuitry
Diagnostic Steps
1
Step 1: Perform visual inspection of the right side HVAC servo motor connector and wiring harness for corrosion, damaged pins, or loose connections. Check for water intrusion around HVAC housing.
2
Step 2: Using a digital multimeter, backprobe the servo motor potentiometer signal wire (typically 5V reference) and measure voltage while manually moving the air door or commanding actuator through climate control diagnostics. Expected range should be 0.5-4.5V with smooth transitions.
3
Step 3: Disconnect the servo motor connector and measure resistance across potentiometer terminals while manually rotating the motor shaft. Resistance should change smoothly without jumps or open circuits (typical range 1-10k ohms depending on manufacturer).
4
Step 4: Remove the right air intake servo motor from HVAC housing and inspect for broken gears, binding linkage, or physical damage. Test motor operation by applying direct 12V power and ground to motor terminals.
5
Step 5: If all previous tests pass, test BCM connector pins for proper voltage supply (5V reference and ground) to servo motor circuit using wiring diagram. Check for circuit shorts to ground or power.
6
Step 6: Replace faulty component (servo motor or repair wiring), clear codes, perform climate control system recalibration/relearn procedure, and verify proper operation through all HVAC modes and temperature settings.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) or climate control module has detected a circuit malfunction in the potentiometer feedback signal from the right side air intake servo motor. The servo motor controls air distribution door positions within the HVAC system, and the potentiometer provi...
The most common cause of B1288 (Servo Motor Potentiometer Airintake Right Circuit Failure) is: Failed or worn potentiometer within the right air intake servo motor assembly
Typical repair costs for B1288 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle safety or drivability. The vehicle is safe to drive, though climate control airflow distribution may be incorrect or stuck in one position, affecting passenger comfort. Repair can be scheduled at convenience.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1288 to identify the root cause.
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Quick Info
Category
Body
System
HVAC Climate Control System
Difficulty
Type
Manufacturer
Recommended Tools
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