Toyota Tundra. Manual — part 1273

Fig. 273: Cranking Holding Function Circuit - Wiring Diagram

INSPECTION PROCEDURE

1. CHECK CRANKING

a. Check the cranking of the engine.

Result

RESULT CHART

Test Result

Proceed To

Cranking possible and holding control operates

A

Does not crank

B

Cranking possible but holding control does not operate C

2008 Toyota Tundra

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

B : Go to step 2

C : Go to step 11

A : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS
TABLE (See PROBLEM SYMPTOMS TABLE )

2. READ VALUE USING TECHSTREAM (STARTER SIGNAL)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Data List/Starter Signal.

e. Read values.

f. Check the result when the ignition switch is turned ON and when the engine is started.

Standard

DATA LIST

NG : Go to step 7

OK : Go to next step.

3. INSPECT STARTER RELAY (ST)

a. Remove the ST relay from the engine room relay block. (See ON-VEHICLE INSPECTION ).

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

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Ignition Switch Position Display (Starter Signal)

ON

OFF

START

ON

Tester Connection

Condition

Specified Condition

3 - 5

When no battery voltage applied to terminals 1 and 2 10 kohms or higher

3 - 5

When battery voltage applied to terminals 1 and 2

Below 1 ohms

2008 Toyota Tundra

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

Fig. 274: Starter Relay (ST) Circuit Diagram

NG : REPLACE STARTER RELAY (ST) . (See STARTER RELAY ).

OK : Go to next step.

4. CHECK HARNESS AND CONNECTOR (PNP SWITCH - ST RELAY)

a. Disconnect the D35 Park/Neutral Position (PNP) switch.

b. Remove the ST relay from the engine room relay block. (See STARTER RELAY ).

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

Standard resistance (Check for open)

TESTER CONNECTION SPECIFIED CONDITION

Standard resistance (Check for short)

TESTER CONNECTION SPECIFIED CONDITION

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

Tester Connection Condition Specified Condition

ST relay (1) - D35-5 Always

Below 1 ohms

Tester Connection

Condition Specified Condition

ST relay (1) or D35-5 - Body ground Always

10 kohms or higher

2008 Toyota Tundra

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

Fig. 275: Checking Harness & Connector (PNP Switch - ST Relay)

OK : Go to next step.

5. CHECK HARNESS AND CONNECTOR (POWER SOURCE)

a. Remove the ST relay from the engine room relay block. (See STARTER RELAY ).

b. Measure the voltage according to the value (s) in the table below.

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR (STARTER RELAY (ST) -
BATTERY, BODY GROUND)

Tester Connection

Condition Specified Condition

ST relay (2) - ST relay (5) Always

11 to 14 V

2008 Toyota Tundra

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