Fault Code 215: Transmission Air Supply Pressure Sensor
J1939: SA 3 SPN 37 FMI 0, 1, 2, 3, 4, 5, 6, 10, 14, 17, 18, 20, 21
Overview
The Endurant XD Series transmissions are equipped with a Transmission Air Supply Pressure Sensor (TASPS) to monitor the air pressure supplied to the transmission. The TASPS connects into the vehicle air supply and provides a pressure input to the Transmission Control Module (TCM). The TCM monitors the pressure input to verify the transmission has the proper air pressure to actuate the clutch and shift rails. The TASPS is mounted in the Mechatronic Transmission Module (MTM) and connected to the TCM at the 74-way Transmission Harness Connector.
The vehicle air supply comes from a dedicated transmission air tank. The primary and secondary air gauges in the cab of the vehicle may not reflect the pressure of the transmission air supply line. The transmission air tank is often isolated from the rest of the vehicle air system with a Pressure Protection Valve and/or Check Valve.
Detection
The TCM monitors the TASPS air pressure signal. If air pressure is outside of normal operating range or a system failure is detected, the fault is set Active.
Conditions to Set Fault Code Active
FMI 0 – Data Valid But Above Normal (Most Severe): Transmission air pressure greater than 145 psi (1000 kPa) for 1 second.
FMI 1 – Data Valid But Below Normal (Most Severe): Transmission air pressure less than 75 psi (517 kPa) for 1 second and one of the following is true:
- a non-Neutral mode is selected
- the vehicle is moving
- the engine has been running for 8 minutes
FMI 2 – Data Erratic: Transmission air pressure out of range, less than 5 psi (34.5 kPa) or greater than 203 psi (1400 kPa) for 5 seconds.
FMI 3 – Voltage Above Normal or Shorted High: TASPS circuit shorted to power for 5 seconds.
FMI 4 – Voltage Below Normal or Shorted Low: TASPS circuit shorted to ground for 5 seconds.
FMI 5 – Current Below Normal or Open Circuit: TASPS circuit open or shorted to ground for 5 seconds.
FMI 6 – Current Above Normal or Shorted Circuit: TASPS reference voltage out of range not between 4.75V to 5.25V for 5 seconds.
FMI 10 - Abnormal Rate of Change: TASPS reported rate of change higher than expected in less than 1 second.
- During a shift greater than 29 PSI (200 kPa)
- Not during a shift greater than 4 PSI (28 kPa)
FMI 14 – Special Instructions: TASPS reported greater than 145 PSI (1000 kPa) after five shifts and vehicle brake air tank pressure continuously reports less than 135 PSI (931 kPa) for 1 second.
FMI 17 – Data Valid but Below Normal (Least Severe): Transmission air pressure less than 75 psi (517 kPa) for 2 seconds with engine off and transmission shutdown in gear.
FMI 18 – Data Valid but Below Normal (Moderately Severe): Transmission air pressure less than 80 psi (552 kPa) for 2 seconds and one of the following is true:
- a non-Neutral mode is selected
- the vehicle is moving
- the engine has been running for 8 minutes
FMI 20 – Data Drifted High: TASPS reported a rate of change higher than expected and remained greater than 145 PSI (1000 kPa) and vehicle brake air tank pressure continuously reports less than 1 second.
FMI 21 – Data Drifted Low: TASPS reported less than 43.5 PSI (300 kPa) and the following is true:
- The vehicle brake air tank pressure reported above 110 PSI (758 kPa)
- The transmission system confirmed the clutch can be fully opened (released)
Fallback
FMI 0:
- Urge to Move and Creep Mode prohibited
FMI 1:
- If transmission is in gear:
- Amber warning lamp on (OEM Specific)
- Coast Mode and Neutral Coast prohibited
- Urge to Move and Creep Mode prohibited
- Inertia Brake activation prohibited
- Upshifts prohibited
- Clutch engagements prohibited
- Non-Neutral modes prohibited
- PTO Mode prohibited
- If transmission is not in gear:
- Red stop lamp on (OEM specific)
- Clutch disengagements prohibited
FMI 2, 3, 4, 5, 6:
- No degraded modes
FMI 10, 14, 20, 21:
- TCM is using the vehicle-reported air pressure information to verify sufficient air pressure is available for normal transmission operation
FMI 17:
- Amber warning lamp on
- No degraded modes
- Engine may not crank
FMI 18:
- Amber warning lamp on (OEM specific)
- Coast Mode and Neutral Coast prohibited
- Urge to Move and Creep Mode prohibited
- Inertia Brake activation prohibited
- Upshifts prohibited
- PTO Mode prohibited
Conditions to Set Fault Code Inactive
FMI 0: TASPS below 145 PSI (1000 kPa) for 1 second.
FMI 1: TASPS above 75 PSI (517 kPa) for 1 second.
FMI 2, 3, 4, 5, 6:TASPS in range for 10 seconds.
FMI 10, 14, 20, 21: Key cycle.
FMI 17: TASPS above 75 PSI (517 kPa) and transmission in neutral.
FMI 18: TASPS above 80 PSI (552 kPa) for 1 second.
Possible Causes
FMI 0:
- Vehicle Air System
- Air compressor governor cut-out set too high or damaged
- Vehicle service event
- Connected to a Service facility air supply source
FMI 1, 18:
- Vehicle Air System
- High system demand during low-speed maneuvering with frequent service brake applications
- Vehicle and/or Trailer air leak(s)
- Air compressor mechanically damaged
- Pressure Protection Valve stuck closed
- Air compressor governor mis-adjusted or damaged
Note: If necessary, refer to OEM and/or vehicle air system manufacture regarding system operation and diagnostics
- Internal transmission
- Air leak
- Transmission Air Supply Pressure Sensor
- Damaged
- Internal failure
FMI 3, 4, 5, 6:
- Transmission Air Supply Pressure Sensor
- Damaged
- Internal failure
- Transmission Air Supply Pressure Sensor Harness
- Wiring shorted to power, shorted to ground or open
- MTM Harness
- Wiring shorted to power, shorted to ground or open
- TCM
- Software issue
- Internal failure
FMI 2, 10, 14, 20, 21:
- Transmission Air Supply Pressure Sensor
- Damaged
- Internal failure
FMI 17:
- Engine was shutdown when air supply pressure low and transmission still in gear
- Transmission service event
- Transmission mis-assembled in a gear position instead of a neutral position.
Additional Tools
- Endurant XD Service Manual TRSM0960
- Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter - RR1029TR
- Digital Volt/Ohm Meter (DVOM)
- 0-200 psi (0-1379 kPa) air pressure gauge
Component Identification
 |
1. Transmission Control Module (TCM) Cover 2. Transmission Control Module (TCM) 3. 74-Way Transmission Harness Connector 4. TCM Side of 74-Way Transmission Harness Connector 5. Transmission Control Module (TCM) Seal 6. MTM Air Inlet Port |
Fault Code 215 Troubleshooting
Set vehicle parking brake and chock wheels.
Record transmission fault codes, FMIs, occurrences, and timestamps from Service Activity Report created during the Diagnostic Procedure.
If Fault Code 215 FMI 0, 1, 18 is Active or Inactive, Go to Step D
If Fault Code 215 FMI 2, 10, 14, 20, 21 is Active or Inactive, Go to Step E
If Fault Code 215 FMI 3, 4, 5, 6 is Active or Inactive, Go to Step B
If Fault Code 215 FMI 17 is Active, connect an auxiliary air supply to the vehicle, air up the vehicle air system to 110-130 PSI (758-896 kPa) and key on. Go to Step V
If Fault Code 215 FMI 17 is Inactive, the transmission air supply pressure is in range and transmission is in neutral. Go to Step V
Key off.
Remove TCM from MTM with 20-Way TCM Vehicle Harness Connector and 20-Way TCM Body Harness Connector connected.
Inspect TCM side of the 74-Way Transmission Harness Connector, verify connector is free from contamination and corrosion; terminals are not bent, spread or loose; and there is no damage to connector body.
Inspect TCM Seal, verify seal is properly installed and there is no damage.
If contamination or damage is found, replace Transmission Control Module (TCM) and Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal Service Procedure.
If no contamination or damage is found, Go to Step C
Key off.
Connect Eaton Breakout Box with 74-Way Eaton Diagnostic Adapter to TCM 74-Way Connector.
Measure resistance at Eaton Breakout Box between Pin 8 and Pin 9. Record reading in table.
Key on.
Measure voltage at Eaton Breakout Box between Pin 7 and Pin 9. Record reading in table.
Compare reading(s) in table.
If readings are in range, replace Mechatronic Transmission Module (MTM). Go to Step V
Note: MTM removal and installation requires transmission be removed from vehicle. Reference Endurant XD Service Manual TRSM0960, Transmission Removal Service Procedure.
If readings are out of range, replace Transmission Control Module (TCM). Go to Step V
| Ignition State | Pins | Range | Reading(s) |
|---|---|---|---|
| Key off | 8 to 9 | 3k-9k Ohms | |
| Key on | 7 to 9 | 4.75–5.25 V |
Key on with engine off.
Connect ServiceRanger.
Go To “Data Monitor”.
From the Default Parameter Files, select “Transmission and Vehicle Air Supply Pressure”.
Key on with engine running.
Allow air pressure to build to governor cut-out.
In ServiceRanger, monitor Transmission Parameter 520524 - Line Pressure Feedback and record value in table.
On the Vehicle Dash Display, monitor Primary (1) and Secondary (2) Air Pressure Gauges and record readings in table.
Key off and allow engine to shut down.
Key on with engine off.
Wait one minute.
After waiting one minute, monitor Transmission Parameter 520524 - Line Pressure Feedback in ServiceRanger and record value in table.
On the Vehicle Dash Display, monitor Primary (1) and Secondary (2) Air Pressure Gauges and record readings in table.
Compare reading(s) in table.
If Transmission - Source readings are out-of-range or erratic and Vehicle - Source (Primary and Secondary) readings are in-range and constant, go to Procedure D of information bulletin TAIB-1015: Fault Code 215 Transmission Air Supply Pressure Sensor (TASPS) located in TRIB-0900: Endurant Family Transmission Information Bulletin Book.
If Vehicle - Source (Primary and Secondary) readings are out-of-range and/or not within +/- 5 PSI (35 kPa) of each other, refer to OEM and/or vehicle air system manufacture regarding system operation and diagnostics. Go to Step V
If all source readings are in-range, within +/- 5 PSI (35 kPa) of each other, the vehicle air system holds pressure, and Fault Code 215 is Inactive, no issues are currently detected. See note below. Go to Step V
Note: Refer to information bulletin TAIB-0876: Transmission Low Air Pressure and/or Clutch Temperature Display Messages located in TRIB-0900: Endurant Family Transmission Information Bulletin Book.
If all source readings are in-range, within +/- 5 PSI (35 kPa) of each other and the vehicle air system holds pressure but an intermittent issue is suspected, contact Eaton Cummins Automated Transmission Technologies for further instructions. Go to Contact Information. Go to Step V
Note: Refer to OEM and/or vehicle air system manufacture regarding governor cut-out specification.
| Source | Parameter | Range | Reading(s) |
|---|---|---|---|
| Transmission | 520524 | 120-135 PSI (827-930 kPa) | |
| Vehicle - Primary (1) Air Pressure Gauge | 120-135 PSI (827-930 kPa) | ||
| Vehicle - Secondary (2) Air Pressure Gauge | 120-135 PSI (827-930 kPa) | ||
| After waiting one (1) minute | |||
| Transmission | 520524 | 120-135 PSI (827-930 kPa) | |
| Vehicle - Primary (1) Air Pressure Gauge | 120-135 PSI (827-930 kPa) | ||
| Vehicle - Secondary (2) Air Pressure Gauge | 120-135 PSI (827-930 kPa) | ||
Fault Code 215 FMI 2, 10, 14, 20 and/or 21 indicates the TCM is using the reported air pressure information from other vehicle sources to verify sufficient air supply pressure is available for normal transmission operation.
If the driver is not reporting any of the following:
- Transmission service lamp
- Transmission low air pressure message
- Transmission performance issue
No further action is required. If necessary, contact Eaton Cummins Automated Transmission Technologies for further diagnostic instructions. Go to Contact Information.
If the driver is reporting one or more of the following:
- Transmission service lamp
- Transmission low air pressure message
- Transmission performance issue
Key off.
Reconnect all connectors and verify all components are properly installed.
Key on with engine off.
Connect ServiceRanger.
Go To “Fault Codes”.
Select “Clear All Faults”.
Operate vehicle and attempt to reset the fault code or duplicate the previous complaint.
Check for fault codes using ServiceRanger.
If no fault codes set and vehicle operates properly, test complete.
If Fault Code 215 sets Active, Go to Step A
If a fault code other than 215 sets Active, troubleshoot per Fault Code Isolation Procedure Index.