Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

TP2 - Check VREF



- Key OFF.

- Disconnect the TP sensor connector.

- Key ON.

- Measure the voltage on the VREF wire at the throttle position sensor harness connector.

- Is the voltage between 4.5 and 5.5 volts?

Yes -- Go to TP3. TP3 - Check Wires to PCM

No -- Go to EEC Pinpoint Test VREF. VREF - Reference Voltage