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Home >> Scion >> 2012 >> iQ L4-1.3L (1NR-FE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0338

P0338





1NR-FE ENGINE CONTROL: SFI SYSTEM: P0338: Crankshaft Position Sensor "A" Circuit
P0338 - Crankshaft Position Sensor "A" Circuit Intermittent

DESCRIPTION

The crankshaft position sensor system consists of a crankshaft angle sensor plate (crankshaft sub-assembly) and Magneto-resistive Element (MRE) type sensor. The crankshaft angle sensor plate has 34 teeth at 10° intervals (2 teeth are missing for detecting top dead center), and is installed on the crankshaft. The crankshaft position sensor generates 34 signals per crankshaft revolution. The ECM uses the G2 signal to distinguish between the cylinders, and uses the NE signal to detect the crankshaft position and engine speed.





- Reference: Inspection using an oscilloscope.





HINT
- The correct waveform is as shown.
- Grounding failure of the shielded wire may cause a noisy waveform.





MONITOR DESCRIPTION

If there is no signal from the crankshaft position sensor despite the crankshaft revolving, the ECM interprets this as a malfunction of the sensor.

When the sensor output voltage remains at below 0.3 V, or higher than 4.7 V for more than 4 seconds, the ECM stores a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

P0335: Crankshaft Position Sensor Range Check (Case 1)





P0335: Crankshaft Position Sensor Range Check (Case 2)





P0337, P0338: Crankshaft Position Sensor Range Check (Low Voltage, High Voltage)





TYPICAL MALFUNCTION THRESHOLDS

P0335: Crankshaft Position Sensor Range Check





P0337: Crankshaft Position Sensor Range Check (Low Voltage)





P0338: Crankshaft Position Sensor Range Check (High Voltage)





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on.

6. Start the engine.

7. Idle the engine for 20 seconds or more [A].

8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].

9. Read pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

11. Input the DTC: P0335, P0337, P0338 or P0339.

12. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform steps [A] and [B] again.

13. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
- If no problem is found by this diagnostic troubleshooting procedure, check for problems by referring to the engine mechanical section.
- The engine speed can be checked by using the Techstream. To perform the check, follow the procedures below:
(1) Connect the Techstream to the DLC3.
(2) Start the engine.
(3) Turn the Techstream on.
(4) Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed.
* The engine speed may be indicated as zero despite the engine running normally. This is caused by a lack of NE signals from the crankshaft position sensor. Alternatively, the engine speed may be indicated as lower than the actual engine speed if the crankshaft position sensor output voltage is insufficient.
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. READ VALUE USING TECHSTREAM (ENGINE SPEED)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed.

(e) Start the engine.

(f) Read the values displayed on the Techstream while the engine is running.

OK:

Correct values are displayed.

HINT
- To check the engine speed change, display the graph on the Techstream.
- If the engine does not start, check the engine speed while cranking.
- If the engine speed indicated on the Techstream remains zero (0), there may be an open or short in the Crankshaft Position sensor circuit.

NG -- CHECK TERMINAL VOLTAGE (POWER SOURCE OF CRANKSHAFT POSITION SENSOR)

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF CRANKSHAFT POSITION SENSOR)





(a) Disconnect the crankshaft position sensor connector.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (CRANKSHAFT POSITION SENSOR - ECM)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (CRANKSHAFT POSITION SENSOR - ECM)

(a) Disconnect the crankshaft position sensor connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK SENSOR INSTALLATION (CRANKSHAFT POSITION SENSOR)





(a) Check the crankshaft position sensor installation.

OK:

Sensor is installed correctly.

NG -- SECURELY REINSTALL SENSOR Installation
OK -- Continue to next step.

5. INSPECT CRANKSHAFT (TEETH OF SENSOR PLATE)

(a) Check the teeth of the sensor plate.

OK:

Sensor plate does not have any cracks or deformation.

NG -- REPLACE CRANKSHAFT (SENSOR PLATE) Disassembly
OK -- Continue to next step.

6. REPLACE CRANKSHAFT POSITION SENSOR

(a) Replace the crankshaft position sensor Removal.

NEXT -- Continue to next step.

7. CHECK WHETHER DTC OUTPUT RECURS (DTC P0335, P0337, P0338 AND/OR P0339)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Start the engine.

(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(g) Read DTCs.

Result





HINT
If the engine does not start, replace the ECM.

B -- REPLACE ECM Removal

A -- END

8. CHECK HARNESS AND CONNECTOR (CRANKSHAFT POSITION SENSOR - ECM)

(a) Disconnect the crankshaft position sensor connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal
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