Pinpoint Test Q: DTC U0100:87

Anti-Theft - With Intelligent Access (IA)

Pinpoint Test Q: DTC U0100:87

Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number

Normal Operation

- DTC U0100:87 (Lost Communication With ECM (Engine Control Module) /PCM "A": Missing Message)- a continuous memory DTC that sets only when the Remote Function Actuator (RFA) module does not receive the Passive Anti-Theft System (PATS) challenge or engine torque data messages from the PCM. It can also be caused by a low vehicle battery state of charge affecting the quality of communication between the modules.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Low battery state of charge

- RFA (Remote Function Actuator) module

- PCM

PINPOINT TEST Q : DTC U0100:87

Q1 CHECK THE BATTERY STATE OF CHARGE

- Check the battery state of charge with the battery condition test.

Does the battery pass the battery condition test?

Yes
GO to Q2.

No
REFER to Charging System to diagnose the low battery voltage condition.

Q2 CHECK FOR MODULE COMMUNICATION ON THE HS-CAN (High Speed Controller Area Network)

- Carry out the network test using the scan tool.

Is the scan tool unable to communicate with any of the modules on the HS-CAN (High Speed Controller Area Network)?

Yes
REFER to Information Bus to diagnose the module that is not communicating with the scan tool.

No
GO to Q3.

Q3 CHECK FOR CORRECT PCM OPERATION

- Disconnect all the PCM connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the PCM connectors and make sure they seat correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new PCM. CLEAR the DTCs. REPEAT the self-test. If the concern is still present, GO to Q4.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

Q4 CHECK FOR CORRECT RFA (Remote Function Actuator) MODULE OPERATION

- Disconnect all the RFA (Remote Function Actuator) module connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the RFA (Remote Function Actuator) module connectors and make sure they seat correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new RFA (Remote Function Actuator) module. CLEAR the DTCs. REPEAT the self-test.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.