GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Remote Keyless Entry Diagnostic System Check is an organized approach to identify problems associated with the Remote Keyless Entry (RKE) system. This check must be the starting point for any RKE complaint, and will direct you to the next logical step in diagnosing the complaint. Understanding the RKE system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

Diagnostic Aids

    • The following conditions may result in an intermittent operation of the RKE system with no DTC stored:
       - Any condition which results in the interruption of power to the receiver
       - Weak or rundown battery
       - Out of range battery or ignition voltage

Specification
Normal battery or ignition voltage: 9.0-16.0 V

       - Weak transmitter battery
       - A loose or damaged ground(s)
       - An open or shorted serial data line
    • An intermittent malfunction in the electronic system may be very difficult to detect and to accurately diagnose. A good description of the complaint may be very useful in locating an intermittent fault condition. Faulty electrical connections or wiring causes most intermitting problems. When an intermitting condition is suspected, check the suspected circuits for the following conditions:
       - Poor mating of connector halves or backed out terminals
       - Improperly formed or damaged terminals
       - Wire chafing
       - Poor wire to terminal connections
       - Dirty or corroded terminals
       - Damage to connector bodies
    •  If the transmitter range decreases or the transmitter does not operate, check for the following conditions:
    • Use the J 35616 Connector Test Adapter Kit whenever a diagnostic procedure requests terminal inspection or probing. Using the adapter ensures no damage to the terminal will occur, and will give an idea of whether contact tension is sufficient.
       - Check if battery replacement is necessary
       - Check for proper range (rainy or snowy weather decreases range)
       - Check for obstructions (other vehicles or objects will decrease range)
       - Electrical interference (cellular phones, power lines, radio towers, garage door openers, etc.)
       - The transmitter is not programmed or synchronized to the vehicle
    • When a RKE system malfunction is corrected, clear the receiver's diagnostic memory to avoid reading the original DTC stored in the memory.
    • Inspect the power door locks and trunk release functions for proper operation. If the locks and/or trunk release do not function properly, repair them before diagnosing the RKE system.
    • Inspect that the transmitter battery terminals are clean and are making good contacts with the battery.
    • Try a second transmitter, if available. If the second transmitter operates, remove the battery and install the battery in the original and perform the synchronizing transmitter procedure. Try the original transmitter again. If the original transmitter operates, replace the battery. If the original transmitter still does not work, replace the original transmitter.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. This test determines if communications can be established with the RKE system.

  2. This test checks for any RKE system DTCs stored in the receiver's memory.

  3. This test determines if communications can be established with other systems connected to the same serial data line.

  4. This test checks the operation of the transmitter in both the manual and passive positions.

  5. This test checks the receiver's power circuit. If the test lamp does not light, there is an open in CKT A823.

  6. This test checks the receiver's ground circuit. If the test lamp does not light, there is an open in the ground circuit.

  7. This test checks for an open in the serial data line between the receiver and the BCM.

Remote Keyless Entry Diagnostic System Check

Step

Action

Value(s)

Yes

No

1

  1. Turn OFF the ignition switch.
  2. Install a scan tool.
  3. Turn ON the ignition switch.
  4. Attempt to establish communications with the RKE system.

Does the scan tool communicate with the RKE system?

--

Go to Step 2

Go to Step 3

2

  1. Select display RKE DTC function using the scan tool.
  2. Check for any RKE DTCs.

Are any RKE DTCs stored?

--

Go to the Applicable DTC Table

Go to Step 4

3

Attempt to establish communications with the other systems connected to the same serial data line (BCM, Radio, etc.).

Does the scan tool communicate with the other systems?

--

Go to Step 5

Go to Scan Tool Does Not Communicate w/Class 2 Data Line

4

Operate the transmitter through all button and switch positions. Refer to Keyless Entry System Operation .

Is the transmitter functioning properly?

--

System OK

Go to Transmitter Programming

5

  1. Turn OFF the ignition switch.
  2. Disconnect the receiver connector.
  3. Connect a test lamp to ground.
  4. Probe connector terminal A (harness side).

Is the test light ON?

--

Go to Step 6

Go to Step 9

6

  1. Connect a test lamp to B+.
  2. Probe connector terminal C (harness side).

Is the test light ON?

--

Go to Step 7

Go to Step 11

7

Check for continuity between the RKE receiver connector terminal B (harness side) and BCM connector C1 terminal B9.

Is there continuity?

--

Go to Step 8

Go to Step 10

8

  1. Replace the remote control door lock receiver. Refer to Receiver Replacement .
  2. Program all RKE transmitters. Refer to Transmitter Programming .

Is the replacement complete?

--

Go to Step 12

--

9

  1. Repair the open in CKT A823.
  2. If the fuse is open, locate and repair the short to ground in the circuit connected to the open fuse.

Are the repairs complete?

--

Go to Step 12

--

10

Locate and repair the open in CKT XM832.

Is the repair complete?

--

Go to Step 12

--

11

Locate and repair the open in between terminal C and G 103.

Is the repair complete?

--

Go to Step 12

--

12

  1. Turn OFF the ignition switch.
  2. Install or connect any components or connectors that were removed or disconnected.
  3. Clear all DTCs.

Are all repairs complete?

--

Go to Step 13

--

13

Operate the transmitter through all button and switch positions. Refer to Keyless Entry System Operation .

Is the transmitter functioning properly?

--

System OK

Go to Keyless Entry System Inoperative