Pinpoint Test A: Neutral Position Sensor Circuit Faults
- NOTE: The neutral position sensor is also known as the rev matching / selected gear / gear shift position sensor.
Refer to ELECTRONIC ENGINE CONTROLS - 2.3L Wiring Diagrams for schematic and connector information. Refer to ELECTRONIC ENGINE CONTROLS - 5.0L Wiring Diagrams for schematic and connector information.
Normal Operation and Fault Conditions
The transmission neutral position sensor is bolted to the transmission housing and detects the position of a magnet mounted on the gear selector shaft. The neutral position sensor provides 3 PWM (pulse width modulation) output signals. The TR_NEUTRAL_RAW and TR_NTRL_RAW2 signals both indicate the gear selector shaft axial position and if the selected gear is odd, even, or neutral. The two separate signals provide redundancy to ensure safe detection of the gear engagement status. The GEAR_SHIFT_C_DC signal indicates shaft rotation and which shift fork is selected. The PCM (Power Control Module) interprets these signals to determine the selected gear. The PCM PID GEARPOS_MAN indicates the selected gear as NEUTRAL, 1, 2, 3, 4, 5, 6, or 7 (for Reverse). As a rationality check, the PCM compares the selected gear detected to the calculated transmission gear ratio using vehicle and engine speed when the clutch pedal is fully released. The sensor data is used for several vehicle features and functions including rev matching, reverse camera activation, reverse parking aid, hill start assist, and reverse lamps.
The neutral position sensor includes a 6 pin electrical connector. The PCM provides a 5 volt VREF signal on pin 1 and SIGNAL RETURN on pin 6. VREF is shared with the particulate filter pressure sensors, if equipped. SIGNAL RETURN is shared with the clutch master cylinder push rod position sensor. The sensor outputs TR_NEUTRAL_RAW on pin 2, GEAR_SHIFT_C_DC on pin 3, and TR_NTRL_RAW2 on pin 4. Pin 5 is not used in this application.
To achieve the required accuracy for the safe operation of these features the sensors need to be programmed to the characteristics of each individual magnet on the gear selector shaft. Once programmed, it is not possible to reprogram or otherwise adjust a sensor. The sensor and magnet must always be installed together as a matched pair.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P086B:00 Neutral Position Sensor 'A' Circuit Range/Performance: No Sub Type Information This DTC sets when the raw neutral position sensor "A" frequency output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power) or an internal sensor fault. TR_NTRL_A_FRQ is less than 225 Hz or greater than 275 Hz when measured by the PCM at C175T-36 PCM P086C:00 Neutral Position Sensor 'A' Circuit Low: No Sub Type Information This DTC sets when the raw neutral position sensor \"A\" duty cycle output from the neutral sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power), an internal sensor fault, or a missing target magnet. TR_NEUTRAL_RAW is less than 7% when measured by the PCM at C175T-36 PCM P086D:00 Neutral Position Sensor 'A' Circuit High: No Sub Type Information This DTC sets when the raw neutral position sensor \"A\" duty cycle output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power) or an internal sensor fault. TR_NEUTRAL_RAW is greater than 93% when measured by the PCM at C175T-36 PCM P08AE:00 Neutral Position Sensor 'B' Circuit Range/Performance: No Sub Type Information This DTC sets when the raw neutral position sensor "B" frequency output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power) or an internal sensor fault. TR_NTRL_B_FRQ is less than 225 Hz or greater than 275 Hz when measured by the PCM at C175T-38 PCM P08AF:00 Neutral Position Sensor 'B' Circuit Low: No Sub Type Information This DTC sets when the raw neutral position sensor \"B\" duty cycle output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power), an internal sensor fault, or a missing target magnet. TR_NTRL_RAW2 is less than 7% when measured by the PCM at C175T-38 PCM P08B0:00 Neutral Position Sensor 'B' Circuit High: No Sub Type Information This DTC sets when the raw neutral position sensor \"B\" duty cycle output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power) or an internal sensor fault. TR_NTRL_RAW2 is greater than 93% when measured by the PCM at C175T-38 PCM P095A:00 Gear Shift Position Circuit 'C': No Sub Type Information This DTC sets when the raw neutral position sensor "C" frequency output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power) or an internal sensor fault. GEAR_SHIFT_C_FRQ is less than 225 Hz or greater than 275 Hz when measured by the PCM at C175T-39 PCM P095C:00 Gear Shift Position Circuit 'C' Low: No Sub Type Information This DTC sets when the raw neutral position sensor \"C\" duty cycle output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power), an internal sensor fault, or a missing target magnet. GEAR_SHIFT_C_FRQ is less than 10% when measured by the PCM at C175T-39 PCM P095D:00 Gear Shift Position Circuit 'C' High: No Sub Type Information This DTC sets when the raw neutral position sensor \"C\" duty cycle output from the neutral position sensor is out of range for the pulse-width modulated signal. This is likely due to a circuit fault (open, short to ground, short to power) or an internal sensor fault. GEAR_SHIFT_C_FRQ is greater than 90% when measured by the PCM at C175T-39 Possible Sources
- Neutral position sensor loose or damaged
- Neutral position sensor internal fault
- Neutral position sensor target magnet dislodged, missing, out of proximity to the sensor
- PCM
- Wiring, terminals or connectors
Visual Inspection and Pre-checks
- Selected gear sensor
- Selected gear sensor connector
- A1 CHECK THE NEUTRAL POSITION SENSOR
- Visually inspect the neutral position sensor and connector for obvious signs of damage.
Were any conditions found during inspection?
Yes REPAIR as necessary. No GO to A2 - A2 CHECK THE NEUTRAL POSITION SENSOR CIRCUITS FOR SHORTS TO VOLTAGE
- Ignition OFF.
- Disconnect PCM C175T .
- Disconnect neutral position sensor C1854 .
- Disconnect clutch master cylinder push rod position sensor C2478 .
- Disconnect particulate filter pressure sensor 11 C1422, if equipped.
- Disconnect particulate filter pressure sensor 21 C1421, if equipped.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead VREF C1854-1 Ground Neutral position sensor "A" C1854-2 Ground Neutral position sensor "C" C1854-3 Ground Neutral position sensor "B" C1854-4 Ground SIGNAL RETURN C1854-6 Ground
Is any voltage present?
Yes REPAIR the short to voltage. No GO to A3 - A3 CHECK THE NEUTRAL POSITION SENSOR CIRCUITS FOR SHORTS TO GROUND
- Ignition OFF.
- Measure:
Positive Lead Measurement / Action Negative Lead VREF C1854-1 Ground Neutral position sensor "A" C1854-2 Ground Neutral position sensor "C" C1854-3 Ground Neutral position sensor "B" C1854-4 Ground SIGNAL RETURN C1854-6 Ground
Are the resistances greater than 10, 000 ohms?
Yes GO to A4 No REPAIR the short to ground. - A4 CHECK THE NEUTRAL POSITION SENSOR CIRCUITS FOR OPENS
- Measure:
Positive Lead Measurement / Action Negative Lead VREF C1854-1 C175T-81 Neutral position sensor "A" C1854-2 C175T-36 Neutral position sensor "C" C1854-3 C175T-39 Neutral position sensor "B" C1854-4 C175T-38 SIGNAL RETURN C1854-6 C175T-7
Are the resistances less than 3 ohms?
Yes GO to A5 No REPAIR the open circuit. - Measure:
- A5 CHECK THE NEUTRAL POSITION SENSOR REFERENCE VOLTAGE CIRCUIT
- Ignition OFF.
- Connect PCM C175T .
- Connect clutch master cylinder push rod position sensor C2478 .
- Connect particulate filter pressure sensor 11 C1422, if equipped.
- Connect particulate filter pressure sensor 21 C1421, if equipped.
- Disconnect neutral position sensor C1854 .
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C1854-1 Ground
Is the voltage between 4.8 and 5.2 volts?
Yes GO to A6 No GO to A15 - A6 CHECK THE NEUTRAL POSITION SENSOR GROUND CIRCUIT
Is the voltage between 4.8 and 5.2 volts?
Yes GO to A7 No GO to A15 - A7 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN NEUTRAL
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in Neutral. Remove hand from gear shift lever
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 45.03 % 54.97 % TR_NTRL_RAW2 36.28 % 43.72 % GEAR_SHIFT_C_DC 51.79 % 68.21 % TR_NTRL_A_FRQ 225 Hz 275 Hz TR_NTRL_B_FRQ GEAR_SHIFT_C_FRQ
Are all of the PID values within the limits?
Yes GO to A8 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A8 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN FIRST GEAR
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in first gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 73.57 % 87.43 % TR_NTRL_RAW2 57.15 % 68.65 % GEAR_SHIFT_C_DC 31.79 % 48.21 %
Are all of the PID values within the limits?
Yes GO to A9 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A9 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN SECOND GEAR
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in second gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 12.57 % 26.43 % TR_NTRL_RAW2 11.35 % 22.85 % GEAR_SHIFT_C_DC 31.79 % 48.21 %
Are all of the PID values within the limits?
Yes GO to A10 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A10 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN THIRD GEAR
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in third gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 73.57 % 87.43 % TR_NTRL_RAW2 57.15 % 68.65 % GEAR_SHIFT_C_DC 51.79 % 68.21 %
Are all of the PID values within the limits?
Yes GO to A11 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A11 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN FOURTH GEAR
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in fourth gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 12.57 % 26.43 % TR_NTRL_RAW2 11.35 % 22.85 % GEAR_SHIFT_C_DC 51.79 % 68.21 %
Are all of the PID values within the limits?
Yes GO to A12 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A12 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN FIFTH GEAR
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in fifth gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 73.57 % 87.43 % TR_NTRL_RAW2 57.15 % 68.65 % GEAR_SHIFT_C_DC 71.79 % 88.21 %
Are all of the PID values within the limits?
Yes GO to A13 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A13 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN SIXTH GEAR
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in sixth gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 12.57 % 26.43 % TR_NTRL_RAW2 11.35 % 22.85 % GEAR_SHIFT_C_DC 71.79 % 88.21 %
Are all of the PID values within the limits?
Yes GO to A14 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A14 CHECK THE NEUTRAL POSITION SENSOR FOR CORRECT OPERATION IN REVERSE
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal for the duration of this test.
- Position the gear shift lever in reverse gear. Remove hand from gear shift lever.
- Access the PCM and monitor the neutral position sensor data.
PID Lower Limit Upper Limit TR_NEUTRAL_RAW 73.57 % 87.43 % TR_NTRL_RAW2 57.15 % 68.65 % GEAR_SHIFT_C_DC 11.49 % 27.91 %
Are all of the PID values within the limits?
Yes GO to A15 No Install a new shift shaft. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) . - A15 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect the PCM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the PCM connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new PCM. Refer to the appropriate Removal and Installation procedure in the appropriate Electronic Engine Controls article. No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.