What Does P1518 Mean?
The PCM has detected a communication error on the serial data circuit between the throttle actuator control module and other control modules. This indicates a problem with the internal network communication used to control the electronic throttle system.
Safety Warning
Electronic throttle control may be disabled, causing reduced power or limp mode. Vehicle may be unsafe to drive normally and should be towed or driven cautiously to repair facility.
Common Causes
35%
Faulty throttle body assembly or TAC module
25%
Damaged CAN bus or serial data wiring between modules
20%
Poor ground connection at throttle body or PCM
15%
PCM internal communication circuit failure
5%
Corroded or damaged electrical connectors
Diagnostic Steps
1
Step 1: Check for other communication-related DTCs in all vehicle modules using scan tool
2
Step 2: Inspect throttle body connector and ground connections for corrosion or looseness
3
Step 3: Using scan tool, monitor live data from TAC module to verify communication is present
4
Step 4: Test continuity and resistance of CAN bus/serial data lines between TAC module and PCM
5
Step 5: If wiring is intact, test throttle body/TAC module voltage supply and ground circuits
Estimated Repair Cost
$300 - $1,500
Parts + labor, varies by vehicle and location
The PCM has detected a communication error on the serial data circuit between the throttle actuator control module and other control modules. This indicates a problem with the internal network communication used to control the electronic throttle system.
The most common cause of P1518 (Throttle Actuator Control (TAC) Module Serial Data Circuit) is: Faulty throttle body assembly or TAC module
Typical repair costs for P1518 range from $300 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Electronic throttle control may be disabled, causing reduced power or limp mode. Vehicle may be unsafe to drive normally and should be towed or driven cautiously to repair facility.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1518 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control
Difficulty
Type
Manufacturer
Recommended Tools
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