For 1990-2009 cars

### Circuit Description

The Remote Control Door Lock Receiver (RCDLR) monitors serial communications between it and the Body Control Module (BCM) over the Class 2 data bus. Each valid message received by the RCDLR contains a changing unique rolling code.

### Conditions for Setting the DTC

The fault is set after the RCDLR receives 16 consecutive incorrect messages.

### Action Taken When the DTC Sets

Stores a DTC B2560 in the receivers memory.

### Conditions for Clearing the DTC

• | The conditions for the fault are no longer present.

• | The use of a scan tool.

• | A history DTC will clear after 50 consecutive ignition cycles if the condition for the fault are no longer present.

### Diagnostic Aids

The following conditions may cause intermittent transmitter or receiver operation.

• | Inspect that the transmitter battery terminals are clean and are making good contact with the battery.

• | Any condition which results in the interruption of power to the receiver.

• | Out of range battery or ignition voltage. Normal voltage range is 9.0-16.0 V.

• | A loose or damaged gound.

• | A loose or damaged power supply.

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. A weak battery may cause the transmitter to malfunction. This test determines if the battery is the cause. After replacement and programming, the transmitter is operated through all positions. A check is made to see if the DTC resets.

2. If the DTC resets the most likely cause is the transmitter.

3. Both transmitters might be out of sync. This test reprograms and synchronizes both transmitters. After reprogramming both transmitters are checked again.

4. If the DTC resets after both transmitters were reprogrammed and synchronized, the most likely cause is the receiver.

#### DTC 2560 RKE Message Validation Error

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Remote Keyless Entry Diagnostic System Check performed? | -- | Go to Step 2 | Go to RKE System Check
2 | Does this DTC set with one particular transmitter? | -- | Go to Step 3 | Go to Step 4
3 |

1. Replace the battery in the transmitter that set the DTC.
2. Reprogram the transmitter. Refer to Transmitter Programming/Synchronization.
3. Operate the transmitter through all button and switch positions.

Does DTC B2560 reset?

--

Go to Step 5

Go to RKE System Check

4 | Does the DTC set with both transmitters? | -- | Go to Step 6 | Go to RKE System Check
5 | Replace the transmitter. Refer to Transmitter Replacement. Is the replacement complete? | -- | Go to RKE System Check | --
6 |

1. Reprogram and synchronize both transmitters. Refer to Transmitter Programming/Synchronization.
2. Operate both transmitters through all button and switch positions.

Does DTC B2560 reset with both transmitters?

--

Go to Step 7

Go to RKE System Check

7 | Replace the receiver. Refer to Receiver Replacement. Is the replacement complete? | -- | Go to RKE System Check | --