Toyota Tundra. Manual — part 1396

Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.

a. Connect the Techstream to the DLC3.

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

c. Enter the following menus: Powertrain/Engine and ECT/Data List/A/F Control System/Short FT #1

and Long FT #1, or Short FT #2 and Long FT #2

d. Read the values displayed on the Techstream.

e. Add together the Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values to obtain the

total Fuel Trim.

Result:

Total of Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values is between -
20% and 20%.

NG : Go to step 4

OK : Go To Next Step

3. CHECK THROTTLE BODY

a. Check for deposits around the throttle valve and throttle valve condition.

OK: No deposits around throttle valve and throttle valve moves smoothly.

NG : Go to step 8

OK : Go to step 9

4. CHECK VVT SYSTEM

a. Allow the engine to idle with the engine warmed up.

b. Enter the following menus: Powertrain/Engine and ECT/Active Test/Control the VVT System

(Bank 1) or Control the VVT System (Bank 2).

c. Turn on Control the VVT System (Bank 1) or Control the VVT System (Bank 2) to advance the

valve timing.

d. Check the engine condition.

OK: The engine stalls or idles roughly when Control the VVT System is ON (VVT system is
OK).

NG : Go to step 10

OK : Go To Next Step

5. CHECK PCV SYSTEM

a. Allow the engine to idle.

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

b. Pinch the positive crankcase ventilation (PCV) hose.

c. Check the engine RPM.

OK: The engine RPM rises when the PCV hose is pinched.

NG : Go to step 11

OK : Go To Next Step

6. CHECK AIR CLEANER FILTER

a. Visually check that the air cleaner filter is not excessively contaminated with dirt or oil.

NG : Go to step 12

OK : Go To Next Step

7. CHECK AIR INDUCTION SYSTEM

a. Check the air induction system for vacuum leakage. (See ON-VEHICLE INSPECTION ).

NG : Go to step 13

OK : Go to step 14

8. REPAIR OR REPLACE THROTTLE BODY

a. Repair or replace the throttle body. (See REMOVAL ).

NEXT : Go to step 15

9. REPLACE ECM

a. Replace the ECM. (See REMOVAL ).

NEXT : Go to step 15

10. CHECK AND REPAIR VVT SYSTEM

NEXT : Go to step 15

11. REPAIR OR REPLACE PCV HOSE

NEXT : Go to step 15

12. REPLACE AIR CLEANER FILTER

NEXT : Go to step 15

13. REPAIR OR REPLACE AIR INDUCTION SYSTEM

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

NEXT : Go to step 15

14. REPLACE MASS AIR FLOW METER

a. Replace the mass air flow meter. (See REMOVAL ).

15. CHECK DTCS

a. Check that the engine coolant temperature is -10 to 50°C (14 to 122°F).

b. Clear the DTC. (See DTC CHECK/CLEAR ).

c. Enter the check mode using the Techstream. (See CHECK MODE PROCEDURE ).

d. Allow the engine to idle for 1 minute.

e. Check that no DTC is present.

NEXT : END

DTC P0550 POWER STEERING PRESSURE SENSOR CIRCUIT MALFUNCTION; DTC P0552
POWER STEERING PRESSURE SENSOR CIRCUIT LOW INPUT; DTC P0553 POWER STEERING
PRESSURE SENSOR CIRCUIT HIGH INPUT

DESCRIPTION

The power steering oil pressure sensor is turned ON when a power steering wheel load occurs by turning the
steering wheel. The ECM regulates the engine idling RPM according to the voltage output of the sensor.

DTC DETECTION CONDITION AND TROUBLE AREA

WIRING DIAGRAM

DTC

Code

DTC Detection Condition

Trouble Area

P0550

Open or short in power steering oil pressure sensor circuit
detected for more than 3 seconds after ignition switch
turned to ON.
(1 trip detection logic)



Open or short in power
steering oil pressure sensor
circuit



Power steering oil pressure
sensor



ECM

P0552

Open in power steering oil pressure sensor circuit detected
for more than 3 seconds after ignition switch turned to ON.



Open in power steering oil
pressure sensor circuit



Power steering oil pressure
sensor



ECM

P0553

Short in power steering oil pressure sensor circuit detected
for more than 3 seconds after ignition switch turned to ON.



Short in power steering oil
pressure sensor circuit



Power steering oil pressure
sensor



ECM

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

Fig. 183: Power Steering Pressure Sensor - Wiring Diagram

MONITOR DESCRIPTION

The ECM monitors the sensor voltage and uses this value to regulates the engine idling speed. When the sensor
output voltage deviates from the normal operating range, the ECM determines that there is a malfunction in the
power steering oil pressure sensor and sets a DTC.

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

Related DTCs

P0550: Power steering pressure sensor range check (Chattering)
P0552: Power steering pressure sensor range check (Low
Resistance)
P0553: Power steering pressure sensor range check (High
Resistance)

Required sensors/components
(Main)

Power steering pressure sensor

Frequency of operation

Continuous

Duration

0.5 seconds

MIL operation

Immediate

Sequence of operation

None

Monitor runs whenever following DTCs not present

None

Time after starter signal ON to OFF

2 seconds or more

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra