Diagnostic Test

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

CHECK THE MANUAL PARK RELEASE (MPR) LEVER AT THE TRANSMISSION
1. Have a helper operate the shifter.
2. Raise the vehicle in the air on a suitable frame contact hoist.
3. Set the Parking Brake.
  WARNING:
  BE SURE TO KEEP HANDS, FEET AND CLOTHING CLEAR OF ROTATING COMPONENTS.
4. Start the vehicle.
5. With the service brakes applied, have a person slowly shift the transmission from park to Drive and back to Park while you observe the MPR lever at the transmission.
  Does the MPR lever move at the transmission when shifting the transmission?
  
  Yes
  - Go To 6
  No
  - Go To 2
DISCONNECT THE MPR CABLE AT THE TRANSMISSION
1. Shut off the vehicle.
2. Disconnect the MPR cable from the lever at the transmission.
  WARNING:
  BE SURE TO KEEP HANDS, FEET AND CLOTHING CLEAR OF ROTATING COMPONENTS.
3. Start the vehicle.
4. With the service brakes applied, have a person slowly shift the transmission from park to Drive and back to Park while you observe the MPR lever at the transmission.
  Does the MPR lever move at the transmission when shifting the transmission?
  
  Yes
  - Go To 3
  No
  - Go To 5
CHECK MPR LEVER IN THE CABIN COMPARTMENT FOR ACTIVATION, OBSTRUCTIONS AND DAMAGE
1. Check the Emergency MPR Lever for activation, obstructions, binding, and damage.
  Were any problems found?
  
  Yes
  - Deactivate the MPR, remove the obstruction, repair the cause of binding or, if necessary, replace the Emergency MPR Lever in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 8HP50/850RE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 4
CHECK MPR CABLE FOR BINDING AND DAMAGE
1. Check MPR Cable for binding or damage that could cause this condition.
  Is the MPR Cable or Lever causing this condition?
  
  Yes
  - Repair or replace the MPR Cable or Lever as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 8HP50/850RE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 5
CHECK MPR LINKAGE ON TRANSMISSION FOR BINDING OR DAMAGE
1. Check MPR linkage on transmission for obstructions, binding, and damage.
  Were any problems found?
  
  Yes
  - Remove the obstruction, repair the cause of binding or, if necessary, replace the valve body in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 8HP50/850RE TRANSMISSION VERIFICATION TEST .
  No
  - Go To 6
READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. With the scan tool, run a vehicle Scan Report, or record the Environmental Data related to the DTCs.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
Did the DTC return?

Yes
- Replace the TCM in accordance with the Service Information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL AND INSTALLATION .
- Perform the TRANSMISSION VERIFICATION TEST. Refer to 8HP50/850RE TRANSMISSION VERIFICATION TEST .
No
- Perform the TESTING FOR AN INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .