LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Dodge and Ram >> 2002 >> Intrepid ES >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0068: Manifold Pressure/Throttle Position Correlation - High Flow/Vacuum Leak Detected >> Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0068: Manifold Pressure/Throttle Position Correlation - High Flow/Vacuum Leak Detected: Testing

NOTE: Diagnose any TPS or MAP component DTCs first before continuing. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If DTC P0501: VEHICLE SPEED SENSOR #1 PERFORMANCE is set along with this DTC, refer to the P0501 diagnostics before continuing. See DTC P0501: VEHICLE SPEED SENSOR #1 PERFORMANCE . The throttle plate and linkage should be free of binding and carbon build-up. Ensure the throttle plate is at the idle position.
  1. Turn ignition on, engine not running. With the DRBIII®, read DTCs and record the related Freeze Frame data. Is the Good Trip counter displayed and equal to zero? If yes, go to next step. If no, go to step  19.
    2. NOTE: This code is enabled on engines with plastic intake manifolds and is intended to shut down the engine if a large crack occurs. A large vacuum leak is most likely the cause of this DTC.
  2. 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 vacuum leaks found? If yes, repair vacuum leak as necessary. If no, go to next step.
  3. Start the engine. With the DRBIII®, monitor the MAP Sensor voltage. Snap the throttle. Does the DRBIII® display MAP voltage from below 2.0 volts at idle to above 3.5 volts at WOT? If yes, go to next step. If no, go to step  12.
  4. Turn ignition on, engine not running. With the DRBIII®, monitor the Throttle Position Sensor voltage while slowly depressing the throttle pedal from the idle position to the wide open throttle position. Does voltage start at approximately 0.8 volt and go above 3.5 volts with a smooth transition? If yes, go to step  19. If no, go to next step.
    5. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
  5. Turn the ignition off. Disconnect the Throttle Position Sensor harness connector. Throttle Position Sensor is located on side of throttle body. Disconnect the PCM harness connectors. Measure the resistance of the 5-Volt Supply circuit from the Throttle Position Sensor harness connector to the appropriate terminal of the Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the 5-Volt Supply circuit.
  6. Measure the resistance between ground and the 5-Volt Supply circuit at the Throttle Position Sensor harness connector. Is the resistance below 100 k/ohms? If yes, repair the short to ground in the 5-Volt Supply circuit. If no, go to next step.
  7. Ensure ignition is off. Reconnect PCM harness connectors. With the DRBIII®, monitor the Throttle Position Sensor voltage. Turn ignition on, engine not running. Connect a jumper wire between the Throttle Position Sensor Signal circuit and the Sensor Ground circuit at the Throttle Position Sensor harness connector. Does the Throttle Position Sensor voltage change from approximately 4.9 volts to below 0.5 volt? If yes, replace the Throttle Position Sensor. If no, go to next step.
    8. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
  8. Turn the ignition off. Disconnect the PCM harness connectors. Measure the resistance of the Throttle Position Sensor Signal circuit from the Throttle Position Sensor harness connector to the appropriate terminal of the Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the Throttle Position Sensor Signal circuit.
  9. Measure the resistance between ground and the Throttle Position Sensor Signal circuit at the Throttle Position Sensor harness connector. Is the resistance below 100 k/ohms? If yes, go to next step. If no, repair the short to ground in the Throttle Position Sensor Signal circuit.
  10. Measure the resistance of the Sensor Ground circuit from the Throttle Position Sensor harness connector to the appropriate terminal of the Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the Sensor Ground circuit.
    11. NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage or terminal push out. Repair as necessary.
  11. There are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
    12. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
  12. Turn the ignition off. Disconnect the MAP Sensor harness connector. Disconnect the PCM harness connectors. Measure the resistance of the 5-Volt Supply circuit from the MAP Sensor harness connector to the appropriate terminal of the Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the 5-Volt Supply circuit.
  13. Measure the resistance between ground and the 5-Volt Supply circuit at the MAP Sensor harness connector. Is the resistance above 100 k/ohms? If yes, go to next step. If no, repair the short to ground in the 5-Volt Supply circuit.
  14. Ensure ignition is off. Reconnect PCM harness connectors. With the DRBIII®, monitor the MAP Sensor voltage. Turn ignition on, engine not running. Connect a jumper wire between the MAP Sensor Signal circuit and the Sensor Ground circuit at the MAP harness connector. Cycle the ignition switch from off to on. With the DRBIII®, monitor the MAP Sensor voltage. Does the DRBIII® display MAP voltage from approximately 4.9 volts to below 0.5 volt? If yes, replace the MAP Sensor. If no, go to next step.
    15. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
  15. Turn the ignition off. Disconnect the PCM harness connectors. Measure the resistance of the MAP Sensor Signal circuit from the MAP Sensor harness connector to the appropriate terminal of the Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the MAP Sensor Signal circuit.
  16. Measure the resistance between ground and the MAP Sensor Signal circuit at the MAP Sensor harness connector. Is the resistance above 100 k/ohms? If yes, go to next step. If no, repair the short to ground in the MAP Sensor Signal circuit.
    17. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
  17. Measure the resistance of the Sensor Ground circuit from the MAP Sensor harness connector to the appropriate terminal of the Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the high resistance in the Sensor Ground circuit.
    18. NOTE: Before continuing, check the PCM harness connectors for corrosion, damage or terminal push out. Repair as necessary.
  18. There are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
    19. WARNING: When the engine is operating, do not stand in a direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing.
  19. The conditions that set the DTC are not present at this time. The following may help in identifying the intermittent condition. With the engine running at normal operating temperature, monitor the DRBIII® parameters related to the DTC while wiggling the wiring harness. Look for parameter values to change and/or a DTC to set. Review the DRBIII® Freeze Frame information. If possible, try to duplicate the conditions under which the DTC was set. Refer to any Technical Service Bulletins (TSB) that may apply. Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Were any of the above conditions present? If yes, repair as necessary. If no, test is complete.
scientia non olet · About LEMON Manuals