Operation CHARM: Car repair manuals for everyone.

Turbo

1. Disconnect harness at TPS and connect an ohmmeter between the two terminals with wires colored red and lt. green/red.
2. Open throttle smoothly from idle to wide open while observing meter. Reading should vary smoothly without sudden jumps up or down. If meter reading is erratic, replace TPS.
3. To check TPS operating voltage, connect TPS harness. With ignition "ON" (engine not running), probe ECM connector terminal M2-14. A digital voltmeter should read the TPS reference signal of 5V.
4. If 5V reference signal is okay, check TPS return signal at ECM terminal M2-13. With engine running, reading should be about 0.5V at idle, increasing to about 5V at wide open throttle.