Toyota Corolla (E120): Inspection procedure
Hint
: 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 Check other dtc output(in addition p0121)
- 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 / dtc info / current codes”.
- read the dtcs.
Result:

Hint
: if any other codes besides p0121 is output, perform the troubleshooting for those dtcs first.


Go to relevant dtc chart
Other materials:
Circuit description
The seat belt buckle switch (lh) circuit consists of the airbag sensor assy
center and front seat inner belt
assy (lh).
Dtc b0126/b0127/27 is recorded when a malfunction is detected in the seat belt
buckle switch (lh) circuit.
Wiring diagram
...
Engine coolant
The coolant level is satisfactory if it is between the “F” and “L” lines on the
reservoir when the engine is cold.
1 Reservoir cap
2 “F” line
3 “L” line
If the level is on or below the “L” line, add coolant up to the “F” line.
■Coolant selection
Only use “To ...
Inspection procedure
1 Inspect dlc3 terminal voltage(tc terminal)
Turn the ignition switch to on.
measure voltage between terminals tc and cg of dlc3.
Ok:
voltage: 10 – 14 v
2 Check harness and connector(dlc3 – body ground)
Check for open and short circuit in harness and connector betw ...


