DTC P0510 - Closed Throttle Position (CTP) Switch Malfunction

1. Turn ignition on. Using a voltmeter, measure voltage (backprobe) between ground and PCM connector "B", terminal No. 4. With throttle at idle position, reading should be 0-1 volt. With throttle above idle, reading should be 4-6 volts. If reading is not as specified, go to next step. If reading is as specified, check for an intermittent problem. See TESTS W/O CODES article.
2. Turn ignition off. Disconnect TP sensor connector. Check for proper connection at CTP switch. Using an ohmmeter, measure resistance between terminals No. 3 and 4. See Fig 1 . When throttle lever-to-stop screw clearance is 0.012 in. (0.3 mm), reading should be 0-3000 ohms. When throttle lever-to-stop screw clearance is 0.024 in. (0.6 mm), reading should be infinity. If reading is as specified, go to next step. If reading is not as specified, adjust or replace TP sensor. Retest system.
3. Check Blue wire or Green/Red wire for an open or short to ground. Repair as necessary. If wires are okay, replace PCM. Retest system.

Fig 1: Testing CTP Switch

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