What Does C1464 Mean?
This code indicates the redundant (secondary) brake pressure transducer signal is faulted. Many stability control systems use dual pressure transducers for safety redundancy. When the secondary transducer fails, the module can still operate using the primary transducer (C1440), but the system loses its ability to cross-check brake pressure readings. The module will typically set a warning but continue operating with reduced diagnostic confidence.
Common Causes
40%
Secondary brake pressure transducer internal failure with strain gauge element degradation or diaphragm leak
25%
Corroded connector at the secondary transducer from brake fluid weepage or splash
20%
Signal wire fault between the secondary transducer and the ABS module
15%
ABS module secondary transducer input channel fault
Diagnostic Steps
1
Step 1: Verify whether the primary pressure transducer (C1440) is also faulted. If both are faulted, suspect a common wiring issue or ABS HCU assembly failure. If only the secondary is faulted, the issue is isolated to the redundant circuit.
2
Step 2: Locate the secondary pressure transducer, often mounted alongside the primary on the ABS hydraulic control unit. Measure its output voltage at rest (approximately 0.5V) and under pedal pressure (should rise linearly to 2.5-4V proportional to pressure).
3
Step 3: Compare the secondary transducer reading against the primary using live data during a slow brake apply. Both should track within 5% of each other. A significant offset or non-linear secondary reading confirms a faulty secondary transducer.
4
Step 4: Check the 5V reference and ground connections at the secondary transducer. If the secondary shares a reference supply with the primary, verify no excessive current draw from either sensor is pulling down the shared reference.
5
Step 5: If the secondary transducer is integral to the ABS HCU assembly, it may not be independently replaceable. Consult the manufacturer service information to determine if the transducer can be removed or if the entire HCU must be replaced.
Estimated Repair Cost
$200 - $1,100
Parts + labor, varies by vehicle and location
This code indicates the redundant (secondary) brake pressure transducer signal is faulted. Many stability control systems use dual pressure transducers for safety redundancy. When the secondary transducer fails, the module can still operate using the primary transducer (C1440), but the system loses ...
The most common cause of C1464 (Pressure Transducer Redundant / Secondary Signal Faulted) is: Secondary brake pressure transducer internal failure with strain gauge element degradation or diaphragm leak
Typical repair costs for C1464 range from $200 to $1,100, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The system continues to operate with the primary pressure transducer, but loses redundant verification. If the primary transducer subsequently fails, the system will have no brake pressure data and may fully disable stability control and brake assist features.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1464 to identify the root cause.
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Quick Info
Category
Chassis
System
ABS / Electronic Brake Distribution
Difficulty
Type
Manufacturer
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