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DTC P1297: No Change In Map From Start To Run: Testing

    NOTE: If a MAP High or Low DTC set along with DTC P1297, diagnose the High or Low DTC first before continuing with this test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  1. Turn ignition on, engine not running. With the DRBIII®, read DTCs. Is the Good Trip counter displayed and equal to zero? If yes, go to next step. If no, go to step  11.
  2. Turn ignition on, engine not running. With the DRBIII®, read the MAP Sensor voltage. Is the voltage below 3.19 volts? If yes, go to next step. If no, go to step  11.
  3. Turn the ignition off. Disconnect the MAP Sensor harness connector. Turn ignition on, engine not running. Measure the voltage of the 5-Volt Supply circuit at the MAP Sensor harness connector. Is the voltage between 4.5 and 5.2 volts? If yes, go to next step. If no, go to step  8.
  4. Turn ignition on, engine not running. With the DRBIII®, monitor the MAP Sensor voltage. Is the voltage above 1.2 volts? If yes, replace the MAP Sensor. If no, go to next step.
  5. Turn the ignition off. Disconnect the PCM harness connectors. Measure the resistance between ground and the MAP Sensor Signal circuit at the MAP Sensor harness connector. Is the resistance below 100 ohms? If yes, repair the MAP Sensor Signal circuit for a short to ground. If no, go to next step.
  6. Measure the resistance between the MAP Sensor Signal circuit and the MAP Sensor ground circuit at the MAP Sensor harness connector. Is the resistance below 100 ohms? If yes, repair the MAP Sensor Signal circuit for a short to the MAP Sensor ground circuit. If no, go to next step.
  7. Remove the MAP Sensor. Inspect the vacuum port, check for restrictions or any foreign materials. Were any restriction found? If yes, repair as necessary. If no, go to step  10.
  8. Turn the ignition off. Disconnect the PCM harness connectors. Measure the resistance between ground and the 5-Volt Supply circuit at the MAP Sensor harness connector. Is the resistance below 100 ohms? If yes, repair the 5-Volt Supply circuit for a short to ground. If no, go to next step.
  9. Measure the resistance of the 5-Volt Supply circuit between the MAP Sensor harness connector and the PCM harness connector. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the 5-Volt Supply circuit for an open.
    10. NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
  10. Using the wiring diagram as a guide, inspect the wire harness and connectors. Pay particular attention to all power and ground circuits. If there are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
    11. 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.
  11. 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 wire harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect the related wire 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.
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