P0851
FA20 ENGINE CONTROL: SFI SYSTEM: P0851, P0852; Park / Neutral Switch Input Circuit Low; 2013 MY FR-S [03/2012 -]
P0851 - Park / Neutral Switch Input Circuit Low
P0852 - Park / Neutral Switch Input Circuit High
DESCRIPTION
MONITOR DESCRIPTION
for Manual Transmission
* The ECM detects the shift change status from the neutral position switch signal, and detects the current selected gear from the engine speed and vehicle speed. If the neutral position switch signal and the shift change status cannot be coordinated, the ECM interprets this as a malfunction, illuminates the MIL, and stores the DTC.
for Automatic Transmission
* If the ECM cannot coordinate the N, P or neutral information from the park/neutral position switch signal with the shift information sent from the TCM through CAN communication, then the ECM interprets this as a malfunction, illuminates the MIL, and stores the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
for Manual Transmission
for Automatic Transmission
TYPICAL MALFUNCTION THRESHOLDS
P0851 (for Manual Transmission)
P0852 (for Manual Transmission)
P0851 (for Automatic Transmission)
P0852 (for Automatic Transmission)
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) Reading and Clearing Diagnostic Trouble Codes.
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 and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
7. Change gear position 3 times or more during Accelerating vehicle to 64 km/h (40 mph) [A]. (for Manual Transmission)
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
8. Drive the vehicle at 10 km/h (6.25 mph) or more for 1 minute or more [B]. (for Automatic Transmission)
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
9. Enter the following menus: Powertrain / Engine / Trouble Codes.
10. 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.
11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
12. Input the DTC: P0851 or P0852.
13. 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.
14. If the test result is INCOMPLETE or N/A and no 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
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT
* 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.
* Stop light switch assembly conditions can be checked using the Techstream.
(1) Connect the Techstream to the DLC3.
(2) Turn the ignition switch to ON.
(3) Turn the Techstream on.
(4) Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch and ST1.
(5) Check the Data List indication when the brake pedal is depressed and released.
PROCEDURE
1. CHECK VEHICLE TYPE
(a) Confirm the transmission.
Result
B -- INSPECT TERMINAL VOLTAGE (POWER SOURCE OF PARK/NEUTRAL POSITION SWITCH ASSEMBLY)
A -- Continue to next step.
2. INSPECT TERMINAL VOLTAGE (POWER SOURCE OF NEUTRAL POSITION SWITCH)
(a) Disconnect the neutral position switch connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
NG -- CHECK HARNESS AND CONNECTOR (NEUTRAL POSITION SWITCH - ECM)
OK -- Continue to next step.
3. INSPECT NEUTRAL POSITION SWITCH
(a) Inspect the neutral position switch Testing and Inspection.
NG -- REPLACE NEUTRAL POSITION SWITCH Removal
OK -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
4. CHECK HARNESS AND CONNECTOR (NEUTRAL POSITION SWITCH - ECM)
(a) Disconnect the ECM connector.
(b) Disconnect the neutral position switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open):
Standard Resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM Removal
5. INSPECT TERMINAL VOLTAGE (POWER SOURCE OF PARK/NEUTRAL POSITION SWITCH ASSEMBLY)
(a) Disconnect the park/neutral position switch assembly connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
NG -- CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - BODY GROUND)
OK -- Continue to next step.
6. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY
(a) Inspect the park/neutral position switch assembly Component Tests and General Diagnostics.
NG -- REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Removal
OK -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
7. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - BODY GROUND)
(a) Disconnect the ECM connector.
(b) Disconnect the park/neutral position switch assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for open):
Standard Resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM Removal