Toyota Tundra. Manual — part 1222

TESTER CONNECTION SPECIFIED CONDITION

Standard resistance (Check for short)

TESTER CONNECTION SPECIFIED CONDITION

Fig. 177: Identifying EFI No. 1 Fuse & A24 ECM Connector

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

Tester Connection

Condition Specified Condition

Battery positive terminal - EFI NO. 1 fuse (1) Always

Below 1 ohms

Tester Connection

Condition

Specified

Condition

Battery positive terminal or EFI NO. 1 fuse (1) - Body

ground

Always

10 kohms or higher

2008 Toyota Tundra

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

OK : Go to next step.

3. INSPECT BATTERY

a. Check that the battery is not depleted.

OK: Battery is not depleted

NG : REPLACE BATTERY

OK : Go to next step.

4. CHECK BATTERY TERMINAL

a. Check that the battery terminals are not loose or corroded.

OK: Battery terminals are not loose or corroded

NG : REPAIR OR REPLACE BATTERY TERMINAL

OK : Go to next step.

5. CHECK WHETHER DTC OUTPUT RECURS

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch ON and turn the Techstream ON.

c. Clear DTCs (See DTC CHECK/CLEAR ).

d. Turn the ignition switch OFF and turn the Techstream OFF.

e. Start the engine and turn the Techstream ON.

f. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

g. Read DTCs.

Result

RESULT CHART

B : CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT
PROBLEMS )

A : REPLACE ECM (See REMOVAL )

DTC P0604 RANDOM ACCESS MEMORY (RAM)

DESCRIPTION

Display (DTC Output) Proceed To

P0560

A

No output

B

2008 Toyota Tundra

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

The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is
functioning properly. It is diagnosed by internal "mirroring" of the main CPU and sub CPU to detect the
Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the
standards, the ECM will illuminate the MIL and set a DTC immediately.

DTC TROUBLE DETECTION CONDITION CHART

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the Techstream. Freeze frame data records the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was
moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data
from the time the malfunction occurred.

1. CHECK DTC

a. Clear DTC (See DTC CHECK/CLEAR ).

b. Turn the ignition switch OFF.

c. Disconnect the cable from the battery negative (-) terminal and wait for 1 minute.

d. Connect the cable to the battery negative (-) terminal.

DTC No.

DTC Detection Condition

Trouble Area

P0604

ECM RAM errors

ECM

Related DTCs

None

Required sensors/Components (Main)

ECM

Required sensors/Components (Related)

None

Frequency of operation

Continuous

Duration

16 seconds

MIL operation

Immediate

Sequence of operation

None

Monitor runs whenever following DTCs not present

None

Main CPU and sub CPU mirroring

Fail

2008 Toyota Tundra

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

e. Turn the ignition switch ON.

f. Connect the Techstream to the DLC3.

g. Turn the Techstream ON.

h. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

i. Check DTC.

OK: P0604 is not present.

NG : REPLACE ECM (See REMOVAL )

OK : CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT
PROBLEMS )

DTC P0606 ECM/PCM PROCESSOR

DESCRIPTION

The ECM continuously monitors its main and sub CPUs. This self-check ensures that the ECM is functioning
properly. If outputs from the CPUs are different and deviate from the standards, the ECM will illuminate the
MIL and set a DTC immediately.

DTC TROUBLE DETECTION CONDITION CHART

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

DTC No.

DTC Detection Condition

Trouble Area

P0606

When either condition below are met



ECM main CPU error



ECM sub CPU error

ECM

Related DTC

P0606: ECM range check

Required sensors/Components (Main)

ECM

Required sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

16 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever the following DTCs are not present

None

2008 Toyota Tundra

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