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

Fuel Pump Relay Circuit Diagnosis



1. With ignition switch "OFF," probe terminal A1 (black/pink wire) of ECM 24 pin A-B connector with test light.
2. Turn ignition "ON" (do not start engine). ECM will energize relay circuit and light will will illuminate for approximately two seconds and then go out. Turn ignition "OFF."
3. At the relay (in engine compartment), probe terminal three (black/yellow wire) with test light.
4. Turn ignition "ON" (do not start engine). ECM will energize relay and light will illuminate for approximately two seconds and then go out. There should also be an audible "click" when the relay is energized.
5. If problems are indicated, refer to Chart A-7 under DIAGNOSIS AND TESTING PROCEDURES; NON-TROUBLE CODE PROCEDURES; A CHARTS. A Charts