P1512 is a manufacturer-specific OBD-II diagnostic trouble code. Because it is manufacturer-specific, its exact definition depends entirely on the vehicle application, ranging from intake manifold runner faults to electronic throttle control issues.
The exact application must be verified before diagnosis. The code indicates the control module detected a fault, but testing is required to identify the root cause and the specific affected component.
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Key Takeaways
- P1512 is a manufacturer-specific code, meaning its exact definition varies by automaker and vehicle application.
- On Ford and Mazda applications, it typically indicates the intake manifold runner control (IMRC) for Bank 1 is stuck closed.
- On GM applications, it points to an electronic throttle control (ETC) or throttle actuator control (TAC) system fault.
- Diagnosis requires verifying the exact factory definition and testing the relevant intake or throttle circuits.
P1512 Code Description and Implications
P1512 is a manufacturer-specific powertrain code. Because the second digit is “1”, the definition is controlled by the automaker rather than the SAE standardized list.
Some Ford and Mazda applications: P1512 indicates Intake Manifold Runner Control (IMRC) Stuck Closed Bank 1. The PCM detects that the IMRC shutter valve or monitor input is stuck in the closed position.
Some GM and Chevrolet applications: P1512 indicates an Electronic Throttle Control (ETC) or Throttle Actuator Control (TAC) system fault. The control module detects an issue with the throttle actuator circuit or performance.
Some BMW applications: P1512 indicates a DISA (Differential Intake System) valve control circuit low or intake manifold runner control fault.
Some Jaguar applications: P1512 indicates a Closed Throttle Position Switch Low Input. When the control module detects an unexpected signal, it sets these trouble codes.
Common Causes of the P1512 Code
Possible causes depend entirely on the specific vehicle application.
For Ford and Mazda IMRC applications, carbon buildup binding the runner flaps, a failing IMRC actuator, damaged vacuum lines, or broken linkage can trigger the code.
For GM ETC/TAC applications, a failing throttle body assembly, damaged throttle position sensor wiring, poor electrical connections, or a failing PCM can cause the fault.
For BMW DISA applications, a failing DISA valve, broken internal plastic components, or damaged control circuit wiring can trigger the code.
For Jaguar applications, a faulty closed throttle position switch, misadjusted throttle linkage, or damaged switch wiring can cause the low input fault.
Symptoms Associated With P1512
The primary symptom is an illuminated Check Engine Light or Service Engine Soon indicator.
On Ford and Mazda applications, drivers may experience a loss of high-end power, rough idling, or hesitation during acceleration due to restricted airflow.
On GM applications, symptoms often include reduced engine power, limp mode activation, harsh or unresponsive throttle, and a flashing warning light.
On BMW applications, symptoms can include rough idling, poor low-end torque, and rattling noises from the intake manifold.
On Jaguar applications, drivers may notice idle speed control issues, stalling when coming to a stop, or erratic throttle response.
Diagnosing the P1512 Trouble Code
Diagnosis must begin by confirming the exact factory definition for the specific make, model, and year.
For Ford and Mazda applications, technicians inspect the IMRC actuator, vacuum lines, and linkage. They test the actuator solenoid and monitor switch circuits for proper operation.
For GM applications, technicians inspect the throttle body for carbon buildup. They test the throttle position sensor circuits and verify the TAC module power and ground.
For BMW applications, technicians inspect the DISA valve for internal mechanical failure and test the control circuit voltage and ground signals.
For Jaguar applications, technicians test the closed throttle position switch for proper voltage output and verify the throttle stop adjustment.
Repairing the P1512 Issue
Repairs follow the confirmed diagnosis for the specific application.
For Ford and Mazda applications, cleaning carbon deposits, repairing vacuum leaks, or replacing the IMRC actuator or linkage resolves the stuck runner fault.
For GM applications, cleaning the throttle body, repairing wiring, or replacing the throttle body assembly if internal sensors fail resolves the ETC fault.
For BMW applications, replacing the DISA valve assembly or repairing the control circuit wiring resolves the intake runner fault.
For Jaguar applications, replacing the throttle position switch or adjusting the throttle linkage resolves the low input fault.
Cost Considerations for P1512 Repairs
Repair costs vary depending on the underlying fault and the vehicle application.
Cleaning an IMRC or throttle body involves minimal parts and labor. Replacing a throttle body or DISA valve requires more parts cost and potential relearn procedures.
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Prevention Strategies for Future Occurrences
Some electrical and mechanical failures cannot be reliably prevented.
Using top-tier fuel and performing regular induction system cleanings can help prevent carbon buildup that binds IMRC flaps and throttle plates.
Inspecting intake vacuum lines and electrical connectors for damage helps prevent intermittent circuit faults and vacuum leaks.
Troubleshooting Tips and Best Practices
Never assume a manufacturer-specific code has a universal meaning. Always verify the exact factory service information for your specific vehicle.
Do not replace a throttle body or IMRC actuator without verifying the wiring, linkages, and sensor signals.
If P1512 is accompanied by other throttle or intake codes, suspect a shared wiring harness issue or systemic vacuum leak rather than multiple simultaneous component failures.
More OBD-II Codes
| P1511 | P1504 | P1498 | P1488 |
| P1487 | P1457 | P1513 | P1514 |
| P1516 | P1518 | P1519 | P1520 |
| P1506 | P1525 | P1529 | P1542 |
| P0121 | P0122 | P0123 | P0220 |
| P0222 | P0223 | P2101 | P2104 |
Frequently Asked Questions
Is P1512 a generic OBD-II code?
No. P1512 is a manufacturer-specific code, meaning its exact definition and diagnostic procedure depend entirely on the vehicle’s make, model, and application.
Can I drive my vehicle with a P1512 code?
It depends on the application. If it triggers reduced engine power or limp mode on a GM vehicle, driving should be avoided. On other applications, it may cause poor performance but allow limited driving.
Will a P1512 code cause my engine to stall?
Yes. On Jaguar or BMW applications, a faulty throttle position switch or DISA valve can cause rough idling, hesitation, or stalling when coming to a stop.
Does P1512 always mean the throttle body is broken?
No. The code often points to carbon buildup, damaged wiring, a failing actuator, or a vacuum leak rather than a mechanically failed throttle body or intake runner.
How do I clear a manufacturer-specific P1512 code?
Clearing the code requires fixing the underlying intake runner, throttle actuator, or switch fault. Simply using a scan tool to erase the code will not repair the root cause.
What Should You Do About the P1512 Code?
Confirm the exact factory definition for your specific vehicle, then follow the applicable manufacturer diagnostic procedure for the relevant system and components.
Because P1512 is manufacturer-specific, testing the exact intake manifold runners, throttle actuator circuits, or position switches identified by the factory service information is required to find the root cause.
Once the fault is confirmed, perform the necessary repairs and verify the fix by clearing the codes and completing a test drive.
