Pinpoint Test B: Gear Shift Position Sensor Signal Mismatch Faults

WARNING: This page is about a different variant/trim than selected.

NOTE: The gear shift position sensor is also know as the rev matching / selected gear / neutral position sensor.

Refer to ELECTRONIC ENGINE CONTROLS - 5.0L for schematic and connector information.

Normal Operation and Fault Conditions

The transmission gear shift position sensor is bolted to the transmission housing and detects the position of a magnet mounted on the gear selector shaft. The gear shift 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 interprets these signals to determine the selected gear. The PCMPID GEARPOS_MAN indicates the selected gear as 0 (for Neutral), 1, 2, 3, 4, 5, 6, or REVERSE. The PCM also uses these signals to calculate the gear shift position states: Neutral, not in Neutral, odd gear, or even gear.

As a rationality check, the PCM compares the selected gear detected to the estimated gear shift position using several inputs including:

Engine speed (RPM)
Clutch pedal position (CPP_STATUS)
Vehicle speed (VSS as reported by the ABS module)
Engine torque (TORQUE)

This data is used for several vehicle features and functions including IPC gear indication, hill start assist, and rev matching features. The rev matching function allows the PCM to target an engine speed to match the resultant input speed of the transmission based on the gear shifter position. The rev matching function is provided to lessen the engine braking force the driver and passengers feel on a downshift. The rev matching function can be turned on and off using the information display menu. If a mismatch exists between the estimated gear shift position state and the reported selected gear from the gear shift position sensor, the PCM will set the GEARPOS_MAN to a degraded or faulted state. Vehicle features that require a gear signal for proper operation may not function properly when GEARPOS_MAN is in a degraded or faulted state.

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 P086A:00	Neutral Position Sensor 'A' Circuit/Open: No Sub Type Information	The DTC sets when there are 3 or more inferred gear shift position mismatch events during a drive cycle. Gear shift position sensor \"A\" reported the shift lever in the odd or even range. Engine speed, vehicle speed, and clutch pedal information indicated the vehicle was NOT moving with the engine running and the clutch pedal released. The PCM estimated the transmission was in neutral. TR_NEUTRAL_RAW less than 30% or greater than 70% RPM at idle or above VSS mph (km/h) CPP_STATUS released
PCM P086E:00	Neutral Position Sensor 'A' Circuit Intermittent/Erratic: No Sub Type Information	The DTC sets when there are 3 or more gear mismatch events during a drive cycle. Gear shift position sensor \"A\" reported the shift lever was NOT in the even range position, but engine speed, vehicle speed, engine torque, and clutch pedal information indicated the vehicle was moving with a transmission gear ratio of an even gear. Alternatively, gear shift position sensor \"A\" reported the shift lever was NOT in the odd range, but engine speed, vehicle speed, engine torque, and clutch pedal information indicated the vehicle was moving with a transmission gear ratio of an odd gear.
PCM P095B:00	Gear Shift Position Circuit 'C' Range/Performance: No Sub Type Information	This DTC sets when the selected gear indicated by the gear shift position sensor and the transmission gear ratio do not match. Transmission gear ratio is calculated by dividing engine speed by vehicle speed when the clutch pedal is released and the engine is producing sufficient torque.

Possible Sources

Clutch pedal binding or sticking
Clutch pedal position sensor fault
Worn, damaged, or slipping clutch
Wheel speed sensor faults
Engine performance faults
Gear shift position sensor
PCM

B1 CHECK CLUTCH PEDAL FOR BINDING
- Ignition OFF.
- Slowly apply and release the clutch pedal
Does the pedal move smoothly without binding or sticking?

Yes GO to B2

No REPAIR as necessary.

B2 CHECK CLUTCH PEDAL POSITION SENSOR

Access and monitor CPP_STATUS

Slowly apply and release the clutch pedal

Does CPP_STATUS indicate released when the pedal is fully released and not released within 1 in (25 mm)?

Yes

GO to B3

No	DIAGNOSE and REPAIR the clutch pedal position system. If any diagnostic trouble codes (DTCs) related to the clutch pedal position switch are present, REFER to the appropriate DTC Index.

B3 CHECK CLUTCH
- Start engine and allow to idle.
- Engage parking brake.
- Press and hold the clutch pedal.
- Position the gear shift lever in fourth gear.
- Increase engine speed to 2000 RPM.
- Slowly release the clutch pedal.
Did the engine stall?

Yes GO to B4

No INSTALL a new clutch disc and pressure plate. REFER to: Clutch Disc and Pressure Plate - 5.0L 32V Ti-VCT

B4 CHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE FOR WHEEL SPEED SENSOR FAULTS
- Enter the following diagnostic mode: ABS On Demand and CMDTC self-test.
Are any wheel speed sensor DTC present?

Yes DIAGNOSE and REPAIR all wheel speed sensor related faults. REFER to: Anti-Lock Brake System (ABS) and Stability Control

No GO to B5

B5 CHECK THE PCM (POWERTRAIN CONTROL MODULE) FOR FAULTS THAT AFFECT CALCULATED TORQUE
- Enter the following diagnostic mode: PCMKOER and CMDTC self-test.
Are any engine performance DTC present?

Yes DIAGNOSE and REPAIR all engine performance related faults. REFER to: Electronic Engine Controls

No GO to B6

B6 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	45 %	55 %
TR_NTRL_RAW2	36.3 %	43.7 %
GEAR_SHIFT_C_DC	51.3 %	68.7 %
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 B7

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B7 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	73.1 %	86.9 %
TR_NTRL_RAW2	56.7 %	68.3 %
GEAR_SHIFT_C_DC	31.3 %	48.7 %

Are all of the PID values within the limits?

Yes

GO to B8

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B8 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	13.1 %	26.9 %
TR_NTRL_RAW2	11.7 %	23.3 %
GEAR_SHIFT_C_DC	31.3 %	48.7 %

Are all of the PID values within the limits?

Yes

GO to B9

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B9 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	73.1 %	86.9 %
TR_NTRL_RAW2	56.7 %	68.3 %
GEAR_SHIFT_C_DC	51.3 %	68.7 %

Are all of the PID values within the limits?

Yes

GO to B10

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B10 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	13.1 %	26.9 %
TR_NTRL_RAW2	11.7 %	23.3 %
GEAR_SHIFT_C_DC	51.3 %	68.7 %

Are all of the PID values within the limits?

Yes

GO to B11

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B11 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	73.1 %	86.9 %
TR_NTRL_RAW2	56.7 %	68.3 %
GEAR_SHIFT_C_DC	71.3 %	88.7 %

Are all of the PID values within the limits?

Yes

GO to B12

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B12 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	13.1 %	26.9 %
TR_NTRL_RAW2	11.7 %	23.3 %
GEAR_SHIFT_C_DC	71.3 %	88.7 %

Are all of the PID values within the limits?

Yes

GO to B13

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B13 CHECK THE GEAR SHIFT 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 gear shift position sensor data.

PID	Lower Limit	Upper Limit
TR_NEUTRAL_RAW	73.1 %	86.9 %
TR_NTRL_RAW2	56.7 %	68.3 %
GEAR_SHIFT_C_DC	11.3 %	28.7 %

Are all of the PID values within the limits?

Yes

GO to B14

No	INSTALL a new gear shift position sensor and magnet as a matched pair. REFER to: Gear Shift Position Sensor

B14 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 service information .

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.