Toyota Sienna Service Manual: Fuel Pump Primary Circuit
DESCRIPTION
- This DTC is designed to detect a malfunction in the fuel pump (FUEL PUMP) relay circuit. When the system is normal, the battery voltage is applied to FPR terminal of the ECM while the FUEL PUMP relay is turned OFF. If the battery voltage is not applied to the FPR terminal while the FUEL PUMP relay is OFF, the ECM interprets this as a malfunction. The ECM then illuminates the MIL and sets a DTC.
- The FUEL PUMP relay switches the fuel pump speed according to the engine
conditions. The fuel
pump operates when the ECM receives the starter-operating signal (STA) and
crankshaft-rotating
signal (NE). The FUEL PUMP relay is turned ON while the engine is idling or
operating at low load.
This causes current to flow through the fuel pump resistor to the fuel pump. The fuel pump then operates at low speed. The FUEL PUMP relay is turned OFF while the engine is cranking or operating at high load. The fuel pump then operates at normal speed.
WIRING DIAGRAM
This troubleshooting procedure is based on the premise that the engine is started. If the engine is not started, proceed to the problem symptoms table (See page ES-27).
INSPECTION PROCEDURE
1 PERFORM ACTIVE TEST BY INTELLIGENT TESTER
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the intelligent tester ON.
(c) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP SP CTL.
(d) Check the operation of the relay while operating it using the intelligent tester.
OK: Operating noise can be heard from the relay.
2 INSPECT RELAY (FUEL PUMP RELAY)
(a) Remove the FUEL PUMP relay from the engine room junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
(c) Reinstall the FUEL PUMP relay.
3 CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY - ECM)
(a) Remove the FUEL PUMP relay from the engine room junction block.
(b) Disconnect the E11 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
(d) Reconnect the ECM connector.
(e) Reinstall the FUEL PUMP relay
REPLACE ECM (See page ES-498)
System Too
DESCRIPTION
The fuel trim is related to the feedback compensation value, not to the basic
injection time. The fuel trim
consists of both the short-term and long-term fuel trims.
The short-ter ...
Random / Multiple Cylinder Misfire Detected
DESCRIPTION
When the engine misfires, high concentrations of hydrocarbons (HC) enter the
exhaust gas. High HC
concentration levels can cause increase in exhaust emission levels. Extremely ...
Other materials:
How to proceed with
troubleshooting
1 VEHICLE BROUGHT TO WORKSHOP
2 INSPECT BATTERY VOLTAGE
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge or replace the battery
before proceeding.
3 BASIC INSPECTION
Turn the ignition switch ON.
Check whether or not the radio receiver turns on.
Result
4 CHE ...
Power back door warning buzzer
INSPECTION
1. POWER BACK DOOR WARNING BUZZER
Check the resistance of the buzzer.
Resistance
If the result is not as specified, replace the buzzer.
NOTICE:
The circuit that causes the buzzer to sounds
is built into the back door ECU, not around
the buzzer.
Directly applying ...
Readiness monitor drive
pattern
1. PURPOSE OF READINESS TESTS
The On-Board Diagnostic (OBD II) system is
designed to monitor the performance of emissionrelated
components, and indicate any detected
abnormalities with DTCs (Diagnostic Trouble Codes).
Since various components need to be monitored in
different d ...
