Pinpoint Test Al: P27B2, P27B3, P27B4, P27B5, P27B6
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
- Normal Operation and Fault Conditions
The TCM monitors the TSS, OSS, ISSA and ISSB sensors to verify the achieved gear matches the selected gear. If the TCM detects a reverse gear when a forward gear is selected, a forward gear when reverse is selected, an incorrect gear ratio or a mismatch between speed sensors, it will set a DTC.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition TCM P27B2:00 Internal Control Module Transmission Range Control Performance: No Sub Type Information This DTC indicates a mismatch between the commanded gear range and the achieved gear range while entering or exiting park. TCM P27B3:00 Internal Control Module Transmission Gear Select Performance: No Sub Type Information This DTC indicates an incorrect gear state. TCM P27B4:00 Internal Control Module Transmission Gear Direction Control Performance: No Sub Type Information This DTC indicates the TCM detected a reverse engagement when a forward gear was selected, or a forward engagement when reverse was selected. TCM P27B5:00 Internal Control Module Transmission Gear Ratio Control Performance: No Sub Type Information This DTC indicates a mismatch between the speed sensor readings and the commanded gear ratio. TCM P27B6:00 Internal Control Module Transmission Speed Sensor Performance: No Sub Type Information This DTC indicates a mismatch between the TSS, ISSA and ISSB sensors. Possible Sources
- Clutch fault
- Speed sensor fault
- TR sensor fault
- GSM fault
- TCM fault
- AL1 CHECK THE GSM (GEAR SHIFT MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, retrieve all diagnostic trouble codes (DTCs) from the GSM.
Are any diagnostic trouble codes (DTCs) present in the GSM?
Yes RESOLVE all GSM diagnostic trouble codes (DTCs) first. REFER to: External Controls - Vehicles With: Column Shift . REFER to: External Controls - Vehicles With: Console Shift . No GO to AL2 - AL2 CHECK THE TCM (TRANSMISSION CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, clear all diagnostic trouble codes (DTCs) from the TCM.
- Road test the vehicle.
- In a parking lot, shift the vehicle between Park, Drive and Reverse, allowing the vehicle to move in both directions.
- Using a diagnostic scan tool, carry out the TCM self-test.
Is DTC P27B2, P27B3, P27B4, P27B5 and/or P27B6 present in the TCM?
Yes GO to AL3 No The fault is not present at this time. If any observable symptoms are present, REFER to: Diagnosis By Symptom . - AL3 RETRIEVE ALL DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE TCM (TRANSMISSION CONTROL MODULE) SELF-TEST
- Ignition ON.
- Using a diagnostic scan tool, retrieve all diagnostic trouble codes (DTCs) from the TCM self-test.
Are any shift solenoid, speed sensor, TR sensor, clutch engagement or module communication diagnostic trouble codes (DTCs) present?
Yes RESOLVE any shift solenoid, speed sensor, TR sensor, clutch engagement, or module communication diagnostic trouble codes (DTCs) first. REFER to the DTC Chart RESOLVE any module communication diagnostic trouble codes (DTCs) second. REFER to the DTC Chart. No If any gear engagement symptoms are present, REFER to: Diagnosis By Symptom . If only P27B2, P27B3, P27B4, P27B5 and/or P27B6 are present with no symptoms, GO to AL4 - AL4 PROGRAM THE TCM (TRANSMISSION CONTROL MODULE) WITH THE LATEST CALIBRATION
- Using a diagnostic scan tool, clear all diagnostic trouble codes (DTCs) from the TCM.
- Program the TCM with the latest calibration. REFER to: Module Programming .
- Carry out the transmission strategy download. REFER to: Transmission Strategy Download .
- Road test the vehicle.
- In a parking lot, shift the vehicle between Park, Drive and Reverse, allowing the vehicle to move in both directions.
- Using a diagnostic scan tool, carry out the TCM self-test.
Is DTC P27B2, P27B3, P27B4, P27B5 and/or P27B6 present in the TCM?
Yes INSTALL a new TCM. REFER to: Transmission Control Module (TCM) . CARRY OUT the transmission strategy download. REFER to: Transmission Strategy Download . No The concern is not present at this time. It might have been caused by a corrupted calibration.