Dtc P0121 [Lf] - Mazda 3 Workshop Manual

Mazda 3 Workshop Manual – Engine + Wiring Diagrams + Diagnostic Trouble Codes
INSPECT ECT SENSOR SIGNAL CIRCUIT
FOR OPEN CIRCUIT
• Inspect the continuity between ECT sensor
7
terminal A (wiring harness-side) and PCM
terminal 2AK.
• Is there continuity?
INSPECT ECT SENSOR GROUND CIRCUIT
FOR OPEN CIRCUIT
• Inspect for continuity between ECT sensor
8
terminal B (wiring harness-side) and PCM
terminal 2AA.
• Is there continuity?
VERIFY TROUBLESHOOTING OF DTC
P0118 COMPLETED
• Make sure to reconnect all disconnected
connectors.
9
• Clear the DTC from the PCM memory using
the WDS or equivalent.
• Start the engine.
• Is the same DTC present?
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
10
(See AFTER REPAIR PROCEDURE
• Are any DTC present?
DTC P0121
• If the PCM detects that the throttle valve opening angle is below 12.5% for 5
s after following conditions are met, the PCM determines that the TP is stuck closed:
MONITORING CONDITION
DETECTION
CONDITION
• If PCM detects that throttle valve opening angle is above 50% for 5 s after
following conditions are met, the PCM determines that TP is stuck open:
MONITORING CONDITION
Downloaded from
[LF].)

DTC P0121 [LF]

TP sensor stuck closed
- Engine coolant temperature is above 70 °C {158 °F}.
- MAF sensor signal is above 32.0 g/s {4.2 lb/min.}.
- Engine speed above 500 rpm
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Yes Go to the next step.
Repair or replace the wiring harness for
No
open circuit, then go to Step 9.
Yes Go to the next step.
Repair or replace the wiring harness for
No
open circuit, then go to the next step.
Replace the PCM, then go to the next step.
Yes
(See PCM REMOVAL/INSTALLATION
[LF].)
No Go to the next step.
Go to the applicable DTC troubleshooting.
Yes
(See DTC TABLE [LF].)
No Troubleshooting completed.
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B3E010201084W15