Codes U0101 and P1603

Good evening.

The 1603 is for the PCM. It has an internal failure.

Looks like you have a failed PCM.

Roy

P1603
Descriptor
Pcm Internal Dual-Port Ram Communication Failure
Probable Causes
Powertrain Control Module (PCM) Fused Ignition Switch Circuit
Powertrain Control Module (PCM) Internal

P1603-PCM INTERNAL DUAL-PORT RAM COMMUNICATION FAILURE

WHEN MONITORED
Ignition on and battery voltage greater than 10 volts.

SET CONDITION
Internal PCM failure detected. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- PCM fused ignition switch circuit
- PCM internal

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. PCM IGNITION CIRCUITS

Turn the ignition off.
Disconnect the PCM harness connectors.
Ignition on, engine not running.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

With a 12-volt test light connected to ground and with special tool #8815 installed, probe the (F202) and (F924) Fused Ignition Switch circuits.
Perform the above check with the Ignition key in the off lock position, Ignition on, engine not running position, and during cranking.
Wiggle the related wire harness while probing the special tool with the test light to try to interrupt the circuit.

Q: Does the test light illuminate brightly?

YES: Go To 2
NO: Repair the open or excessive resistance in the (F202) and (F924) Fused Ignition Switch (Off, Run, Start) circuits. Inspect the related fuse, if the fuse is open check the circuits for a short to ground. Perform the POWERTRAIN VERIFICATION TEST. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > Powertrain Verification Test

2. PCM

The Powertrain Control Module is reporting internal errors.

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Q: Were there any problems found?

YES: Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > Powertrain Verification Test
NO: Replace and program the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests > Powertrain Verification Test

U101

U0101
Descriptor
Lost Communication With Tcm
Probable Causes
Controller Area Network (CAN) B or CAN C Bus Circuits Open or Shorted
Controller Area Network (CAN) C Bus Failure Open or Shorted Condition
DTCs Related to Battery Voltage, Ignition, or VIN Messages
Module That Set This DTC
Powertrain Control Module (PCM)
Totally Integrated Power Module (TIPM) Misconfigured
Transmission Control Module (TCM) (Powertrain Control Module)
Transmission Control Module (TCM) Power and Ground

How are you making out?

Roy

If you looked at the possibilities for the 1603, it states PCM internal failure if the powers are good to the unit.

The TIPM is a body control module, not a PCM.

Roy

That is correct.

You need to replace it and have it programmed to your car.

Roy