DRIVEABILITY

Symptom: P1299-VACUUM LEAK FOUND (IAC FULLY SEATED)

When Monitored and Set Condition:

P1299-VACUUM LEAK FOUND (IAC FULLY SEATED) When Monitored: With the engine running. Set Condition: The MAP sensor signal does not correlate to the TPS signal.

POSSIBLE CAUSES VACUUM LEAK MAP SENSOR DEFECTIVE (OUT OF CALIBRATION) TPS DEFECTIVE (VOLTAGE GREATER THAN 1.5 AT REST) TPS DEFECTIVE (VOLTAGE LESS THAN 3.4 AT WIDE OPEN THROTTLE)

TEST ACTION APPLICABILITY 1 Note: A large vacuum leak is the most likely cause of this DTC. All Inspect the Intake Manifold for vacuum leaks. Inspect the Power Brake Booster for any vacuum leaks. Inspect the PCV system for proper operation or any vacuum leaks. Were any problems found? Yes → Repair vacuum leak as necessary. Perform the Powertrain Verification Test - Ver 5. No → Go To 2

2 Note: Throttle must be fully closed and against throttle stop. All Turn ignition on. With the DRB in Sensors, read the Throttle Position Sensor voltage. Is the voltage 1.5 volts or less with the throttle closed?

Yes → Go To 3

No → Replace the Throttle Position Sensor. Perform the Powertrain Verification Test - Ver 5.

3 Turn ignition off. All Tee-in a vacuum gauge to a manifold vacuum source. Start the engine and allow to idle. Note: If the engine will not idle, maintain a constant RPM above idle. With the DRB in Sensors, read the MAP Sensor Vacuum value. Is the DRB reading within 1Љ of the teed-in vacuum gauge? Yes → Go To 4 No → Replace the MAP Sensor. Perform the Powertrain Verification Test - Ver 5.

223 DRIVEABILITY

P1299-VACUUM LEAK FOUND (IAC FULLY SEATED) — Continued

TEST ACTION APPLICABILITY 4 Turn ignition on. All With the DRB in Sensors, monitor the Throttle Position Sensor voltage while slowly opening the throttle to wide open. Is the maximum voltage at least 3.4 volts at wide open throttle? Yes → Test Complete. No → Replace the Throttle Position Sensor. Perform the Powertrain Verification Test - Ver 5.

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