Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Intake air temperature circuit / Inspection procedure
Toyota Corolla (E120): Inspection procedure
Hint
:
- if different dtcs related to different systems that have terminal e2 as the ground terminal are output simultaneously, terminal e2 may be open.
- Read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was lean or rich, etc. At the time of the malfunction.
1 Read value of hand–held tester or obd ii scan tool(intake air temperature)
- Connect the hand–held tester or the obd ii scan tool to the dlc3.
- turn the ignition switch on and push the hand–held tester or the obd ii scan tool main switch on.
- select the item ”diagnosis / enhanced obd ii / data list / all / intake air” and read its value displayed on the hand–held tester or the obd ii scan tool.
Temperature: same value as the actual intake air temperature.
Result:
Hint
:
- if there is an open circuit, the hand–held tester or the obd ii scan tool indicates –40 °C (–40°f).
- If there is a short circuit, the hand–held tester or the obd ii scan tool indicates 140 °C (284°f) or more.
2 Read value of hand–held tester or obd ii scan tool(check for open in wire harness)
- Disconnect the m1 mass air flow sensor connector
- connect terminals tha and e2 of the mass air flow sensor wire harness side connector.
- turn the ignition switch on.
- select the item ”diagnosis / enhanced obd ii /
data list / all / intake air” and read its value displayed
on the hand–held tester or the obd ii scan tool.
Temperature value: 140 °C (284°f) or more
- reconnect the mass air flow sensor connector.
3 Read value of hand–held tester or obd ii scan tool(check for open in ecm)
- Disconnect the m1 mass air flow sensor connector.
- connect the terminals tha and e2 of the e3 ecm connector.
Hint
: before checking, do a visual and contact pressure check on the ecm connector.
- turn the ignition switch on.
- select the item ”diagnosis / enhanced obd ii /
data list / all / intake air” and read its value displayed
on the hand–held tester or the obd ii scan tool.
Temperature value: 140 °C (284°f) or more
- reconnect the mass air flow sensor connector.
Confirm good connection at ecm. If ok, replace ecm
4 Read value of hand–held tester or obd ii scan tool(check for short in wire harness)
- Disconnect the m1 mass air flow sensor connector.
- turn the ignition switch on.
- select the item ”diagnosis / enhanced obd ii /
data list / all / intake air” and read its value displayed
on the hand–held tester or the obd ii scan tool.
Temperature value: –40 °C (–40°f)
- reconnect the mass air flow sensor connector.
5 Read value of hand–held tester or obd ii scan tool(check for short in ecm)
- Disconnect the e3 ecm connector.
- turn the ignition switch on.
- select the item ”diagnosis / enhanced obd ii /
data list / all / intake air” and read its value displayed
on the hand–held tester or the obd ii scan tool.
Temperature value: –40 °C (–40°f)
- reconnect the ecm connector.
Replace ecm
Other materials:
Steering wheel audio switches
Some audio features can be controlled using the switches on the steering wheel.
Operation may differ depending on the type of multimedia system or navigation
system. For details, refer to the manual provided with the multimedia system or
navigation system.
Operating the multimedia system using ...
Before driving
Observe the following
before starting off in the
vehicle to ensure safety of
driving.
Floor mat
Use only floor mats designed
specifically for vehicles of the
same model and model year as
your vehicle. Fix them securely
in place onto the carpet.
1. Insert the retaining hooks
(clips) into the floor ma ...
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...