Toyota Tundra. Manual — part 1297

2. REMOVE CIRCUIT OPENING RELAY (C/OPN)

a. Remove the engine room relay block cover.

b. Remove the circuit opening relay from the engine room relay block.

3. INSPECT CIRCUIT OPENING RELAY

a. Measure the resistance according to the value (s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

If the result is not as specified, replace the relay.

Fig. 384: Identifying Circuit Opening Relay Connector Terminals

4. INSTALL CIRCUIT OPENING RELAY

5. CONNECT CABLE TO NEGATIVE BATTERY TERMINAL

A/F SENSOR HEATER RELAY

ON-VEHICLE INSPECTION

1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

memory and settings. As a result, after turning the ignition switch
OFF, wait 90 seconds or more before disconnecting the cable from
the negative (-) battery terminal.

Tester Connection

Condition

Specified Condition

3 - 5

When battery voltage is not applied to terminals 1 and 2 10 kohms or higher
When battery voltage is applied to terminals 1 and 2

Below 1 ohms

NOTE:

Some systems need to be initialized after the cable is reconnected (see
INITIALIZATION ).

NOTE:



Some systems need to be initialized after the cable is reconnected

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

2. REMOVE INTEGRATION RELAY (UNIT E)

a. Remove the engine room relay block cover.

b. Using a screwdriver, detach the 2 claws and disconnect the integration relay from the engine room

relay block.

HINT:

Tape the screwdriver tip before use.

c. Disconnect the 3 connectors.

3. INSPECT INTEGRATION RELAY (A/F SENSOR HEATER RELAY)

Fig. 385: Locating Integration Relay Claws

(see INITIALIZATION ).



After the ignition switch is turned OFF, the navigation system
requires approximately 90 seconds to record various types of
memory and settings. As a result, after turning the ignition switch
OFF, wait 90 seconds or more before disconnecting the cable from
the negative (-) battery terminal.

NOTE:



Some relays are built into the integration relay (unit E). The integration
relay cannot be disassembled. If there is a malfunction in the circuit of the
integration relay, replace the integration relay.



The internal circuit of the integration relay is as shown in the illustration
below. Inspect the integration relay using the following procedures.

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

a. Measure the resistance of the A/F fuse.

1. Measure the resistance according to the value (s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

If the result is not as specified, replace the A/F fuse.

b. Measure the resistance of the A/F relay circuit.

1. Measure the resistance according to the value (s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Fig. 386: Integration Relay (Unit E) Inner - Circuit Diagram

Tester Connection Condition Specified Condition

A/F fuse

Always

Below 1 ohms

Tester

Connection

Condition

Specified

Condition

1C-1 - 1A-4

When battery voltage is not applied between 1A-2
and 1A-3

10 kohms or higher

When battery voltage is applied between 1A-2 and

Below 1 ohms

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

If the result is not as specified, replace the integration relay.

4. INSTALL INTEGRATION RELAY (UNIT E)

a. Connect the 3 connectors.

b. Install the integration relay to the engine room relay block.

Fig. 387: Identifying Integration Relay Connector Terminals

c. Install the engine room relay block cover.

5. CONNECT CABLE TO NEGATIVE BATTERY TERMINAL

1A-3

NOTE:

Some systems need to be initialized after the cable is reconnected (see
INITIALIZATION ).

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra