The 5-volt supply output is monitored when ignition is on. DTC will be stored in Powertrain Control Module (PCM) memory if 5-volt supply output to sensors is less than 3.5 volts for 4 seconds. Possible causes for DTC to set are: intermittent condition, defective A/C pressure sensor, defective Manifold Absolute Pressure (MAP) sensor, defective Throttle Position (TP) sensor, defective PCM, or defective connectors or wiring.
1.Turn ignition on. Using scan tool, read DTCs. If Good Trip counter is displayed for DTC P1496 and displayed count is "0", go to next step. If Good Trip counter is not displayed for DTC P1496 or displayed count is not "0", go to step 8.
2.Ensure ignition is off. Disconnect TP sensor connector. TP sensor is mounted on throttle body. Turn ignition on. Measure voltage between ground and Pink/Yellow wire at TP sensor connector. If voltage is less than 4.5 volts, go to next step. If voltage is 4.5 volts or more, go to step 7.
3.Turn ignition off. Ensure TP sensor connector is still disconnected. Connect a voltmeter between ground and Pink/Yellow wire at TP sensor harness connector. Turn ignition on. Note voltage reading. Disconnect MAP sensor connector and note voltage reading. If voltage did not change from less than 4.5 volts to more than 4.5 volts, go to next step. If voltage changed from less than 4.5 volts to more than 4.5 volts, replace MAP sensor.
4.Ensure ignition is on and voltmeter is still connected between ground and Pink/Yellow wire at TP sensor harness connector. Note voltage reading. Disconnect A/C pressure sensor connector. A/C pressure sensor is located on A/C refrigerant line between filter-drier and expansion valve in right rear corner of engine compartment. If voltage did not change from less than 4.5 volts to more than 4.5 volts, go to next step. If voltage changed from less than 4.5 volts to more than 4.5 volts, replace A/C pressure sensor.
5.Turn ignition off. Ensure TP sensor, MAP sensor and A/C pressure sensor connectors are still disconnected. Disconnect PCM connectors. PCM is located on left side of engine compartment, in front of battery. Measure resistance between ground and Pink/Yellow wire at TP sensor harness connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in 5-volt supply circuit (Pink/Yellow wire) to TP sensor. See WIRING DIAGRAMS article.
6.At this time PCM is assumed to be defective. Replace PCM. Program the new PCM. See PROGRAMMING.
7.Turn ignition off. Reconnect TP sensor connector. Disconnect MAP sensor connector and note voltage reading on voltmeter. Turn ignition on. Measure voltage between ground and 5-volt supply circuit at terminal No. 3 at MAP sensor harness connector. If voltage is 4.5 volts or more, go to next step. If voltage is less than 4.5 volts, replace TP sensor.
8.At this time, conditions for DTC to set do not exist or fault is an intermittent problem. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Using scan tool, monitor parameters related to DTC while wiggling connectors and wiring harness. If value changes while wiggling connectors and wiring harness, repair connectors and wiring harness where wiggling caused value to change. If value does not change, review Freeze Frame data using scan tool. Attempt to duplicate condition that caused DTC to set. Check for any related technical service bulletins that may apply. Visually inspect related connectors and wiring harness. Repair connectors and wiring harness as necessary. See WIRING DIAGRAMS article. If no problems are indicated, test is complete.
https://www.2carpros.com/articles/mitchell1eautorepair-car-repair-manuals
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Wednesday, July 21st, 2010 AT 9:46 PM