Toyota Sequoia (2005). Manual - part 125

A21381

Engine Room J/B

EFI No. 1 Fuse

B17417

E4

BATT

ECM Connector

–

DIAGNOSTICS

ENGINE

DI–295

489

4

Check for open and short in harness and connector between ECM and EFI No. 1
fuse, EFI No. 1 fuse and battery.

PREPARATION:
(a)

Remove the EFI No. 1 fuse from the engine room J/B.

(b)

Disconnect the E4 ECM connector.

CHECK:
Measure the resistance between the wire harness side connec-
tor.
OK:

Standard:

Tester Connection

Specified Condition

Engine Room J/B (EFI No. 1 fuse 

terminal 2) – BATT (E4–3)

Below 1 

Ω

Engine Room J/B (EFI No. 1 fuse 

terminal 2) or BATT (E4–3) – 

Body ground

10 k

Ω

 or higher

NG

Repair or replace harness or connector.

OK

5

Check the battery (See page 

CH–1

).

NG

Replace battery.

OK

Check and replace engine room J/B.

DI–296

–

DIAGNOSTICS

ENGINE

490

DTC

P0604

Internal Control Module Random Access
Memory (RAM) Error

DTC

P0606

ECM/PCM Processor

DTC

P0607

Control Module Performance

DTC

P0657

Actuator Supply Voltage Circuit / Open

MONITOR DESCRIPTION

The ECM continuously monitors its internal memory status, internal circuits, and output signals to the throttle
actuator. This self–check insures that the ECM is functioning properly. If any malfunction is detected, the
ECM will set the appropriate DTC and illuminate the MIL. 
The ECM memory status is diagnosed by internal ”mirroring” of the main CPU and the sub CPU to detect
RAM (Random Access Memory) errors. The two CPUs also perform continuous mutual monitoring.
The ECM sets a DTC if: 1) outputs from the 2 CPUs are different and deviate from the standards, 2) the sig-
nals to the throttle actuator deviate from the standards, 3) a malfunction is found in the throttle actuator sup-
ply voltage, and 4) any other ECM malfunction is found.

DTC No.

DTC Detecting Condition

Trouble Area

P0604

P0606

P0607

P0657

ECM malfunction

ECM

MONITOR STRATEGY

P0604

Random access memory (RAM) error

R l t d DTC

P0606

CPU malfunction

Related DTCs

P0607

ECM range check

P0657

ETCS power supply

Required sensors/components

ECM

Frequency of operation

Continuous

Duration

Within 1 sec.

MIL operation

Immediate

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever these

DTCs are not present

See page 

DI–18

The typical enabling condition is not avail-

able

–

DI3IK–13

–

DIAGNOSTICS

ENGINE

DI–297

491

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

P0604:

RAM

RAM check failure

P0606:

Either of the following conditions is met

Condition 1 or 2

1. Difference between TP of main CPU and TP of sub CPU

0.3 V or more

2. Difference between APP of main CPU and APP of sub

CPU

0.3 V or more

P0607:

Either of the following conditions is met

Condition 1 or 2

1. All of the following conditions are met

Condition (a), (b) and (c)

(a) CPU reset

1 time or more

(b) Difference between TP and APP learned

0.4 V or more

(c) Electronic throttle actuator

OFF

2. CPU reset

2 times or more

P0657:

ECTS power supply when ignition switch OFF to ON

7 V or more

INSPECTION PROCEDURE

HINT:
Read freeze frame data using 

the hand−held tester.

 Freeze frame data records the engine conditions when

a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air–fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.

Replace ECM (See page 

SF–80

).

DI–298

–

DIAGNOSTICS

ENGINE

492

DTC

P0617

Starter Relay Circuit High

MONITOR DESCRIPTION

While the engine is being cranked, the battery positive voltage is applied to terminal STA of the ECM.
If the vehicle is being driven and the ECM detects the starter control signal (STA), the ECM concludes that
the starter control circuit is malfunctioning. The ECM will turn on the MIL and a DTC is set.

DTC No.

DTC Detection Condition

Trouble Area

P0617

When all conditions (a), (b) and (c) are satisfied for 20 seconds

with battery (+B) voltage 10.5 V or more

(a) Vehicle speed 

 20 km/h (12.4 mph)

(b) Engine revolution 

 1,000 rpm

(c) STA signal ON

Park/neutral position switch

Starter relay circuit

Ignition switch

ECM

MONITOR STRATEGY

Related DTCs

P0617

Starter signal error

R

i d

/

t

Main sensors/components

Starter signal

Required sensors/components

Related sensors/components

Vehicle speed sensor, Engine speed sensor

Frequency of operation

Continuous

Duration

20 sec.

MIL operation

Immediate

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

It

Specification

Item

Minimum

Maximum

The monitor will run whenever this DTC is
not present

See page 

DI–18

Battery voltage

10.5 V

–

Vehicle speed

20 km/h (12.4 mph)

–

Engine RPM

1,000 rpm

–

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

Starter signal

ON (at ”more than 20 km/h (12.4 mph) and more than 1,000 rpm”)

DID8D–01