Diagnostic Test

CHECK FOR ENGINE CHARGING SYSTEM DIAGNOSTIC TROUBLE CODES (DTCs)
1. With the scan tool, read Powertrain Control Module (PCM) DTCs.
  Are any Engine Charging System DTCs set?
  
  Yes
  - Repair Engine Charging System DTCs. Refer to DTC INDEX .
  - Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .
  No
  - Go To 2
CHECK THE (A901) FUSED B+ POWER CIRCUIT
1. Turn the ignition off.
2. Disconnect the ESM harness connector.
3. Turn the ignition on.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
4. Using a 12-volt test light connected to ground, check the (A901) Fused B+ Power Circuit at the ESM harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 3
  No
  - Repair the (A901) Fused B+ Power Circuit for an open or high resistance.
  - Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .
CHECK THE (Z156) GROUND CIRCUIT
1. Turn the ignition off.
2. Using a 12-volt test light connected to 12-volts, check the (Z156) Ground Circuit in the ESM harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the (Z156) Ground Circuit for an open or high resistance.
  - Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .
CHECK FOR AN ACTIVE DTC
1. Reconnect all disconnected harness connectors.
2. With the scan tool, clear ESM DTCs.
3. Start the Engine and raise the engine speed to 2, 000 rpm for 10 seconds.
4. With the scan tool, read ESM DTCs and record on the repair order.
  Did the DTC return?
  
  Yes
  - Using the schematics as a guide, check the Electronic Shift Module (ESM) connector and all related in-line connector terminals for corrosion, damage, or pushed out terminals. Pay particular attention to all power and ground circuits. If no problems are found, replace the ESM in accordance with the Service Information. Refer to SHIFTER, TRANSMISSION, REMOVAL AND INSTALLATION, 8HP50/850RE or SHIFTER, TRANSMISSION, REMOVAL AND INSTALLATION, 8HP75 .
  - Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .
  No
  - Perform the ESM VERIFICATION TEST. Refer to ELECTRONIC SHIFT MODULE (ESM) VERIFICATION TEST .
  - Test complete.