- The RCDLR input does not match the state of the mode switch received from the IPM.
- The RCDLR receives a message from the IPM, indicating that a switch has been pressed, without seeing the corresponding input go active.
- The RCDLR mode data input is active for more than 60 seconds, without seeing the corresponding message from the IPM.
Action Taken When the DTC Sets
The Service Vehicle Soon (SVS) indicator will illuminate. Also, the following scenarios may take place
- If the RCDLR senses a change on its ignition mode data input, but does not receive the corresponding message from the IPM, the RCDLR will enable the backup power mode. The backup power mode will be the old power mode. If a second change is sensed by RCDLR on its ignition mode data input, without the corresponding message from the BCM, the backup power mode will be changed accordingly to signal sensed.
- If the RCDLR receives a message from the IPM, indicating that a switch has been pressed, without sensing the change itself, the setting of the backup power moding will be disabled for the current ignition cycle.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
Diagnostic Aids
The setting of this DTC can be caused by various failures
- The RCDLR malfunction
- The IPM malfunction
- The ignition mode switch malfunction
- The ignition mode data input circuits to either RCDLR or IPM
Test Description
The number below refers to the step number on the diagnostic table.
- 3: This step checks for a proper reading of the ignition mode switch by the RCDLR.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Power Distribution Schematics in Wiring Systems Connector End View Reference: Master Electrical Component List in Wiring Systems | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Did you retrieve any of the following DTCs? B1325 B1380 B1385 | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 | |
| 3 | With the scan tool, monitor the ignition mode switch parameter under RCDLR data. Press the lower and upper ignition mode switch buttons one at a time. Does the parameter value toggle between Idle and ACC/OFF and between Idle and Run respectively? | Go to Step 4 | Go to Step 11 | |
| 4 | Turn OFF the ignition. Disconnect the ignition mode switch. Measure the voltage between the instrument panel module (IPM) ignition mode switch reference voltage circuit at the ignition mode switch connector and a good ground. Is the voltage measured within the specified range? | B+ | Go to Step 5 | Go to Step 6 |
| 5 | Measure the voltage between the IPM ignition mode switch reference voltage circuit and the IPM ignition mode signal circuit at the ignition mode switch connector. Is the voltage measured within the specified range? | B+ | Go to Step 7 | Go to Step 8 |
| 6 | Disconnect the IPM. Test the IPM ignition mode switch reference voltage circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 21 | |
| 7 | Disconnect the IPM. Test the IPM ignition mode data signal circuit of the IPM for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 9 | |
| 8 | Disconnect the IPM. Test the IPM ignition mode data signal circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 21 | |
| 9 | While measuring the resistance between the IPM ignition mode data signal and IPM ignition mode switch reference voltage circuits at the ignition mode switch, press the OFF/ACC button of the ignition mode switch. Is the value measured approximately as specified? | 270 ohms | Go to Step 10 | Go to Step 23 |
| 10 | While measuring the resistance between the IPM ignition mode data signal and IPM ignition mode switch reference voltage circuits at the ignition mode switch, press the START button of the ignition mode switch. Is the value measured approximately as specified? | 450 ohms | Go to Step 21 | Go to Step 23 |
| 11 | Turn OFF the ignition. Disconnect the ignition mode switch. Measure the voltage between the remote control door lock receiver (RCDLR) ignition mode data signal circuit at the ignition mode switch connector and a good ground. Is the voltage measured within the specified range? | B+ | Go to Step 12 | Go to Step 14 |
| 12 | Install a test lamp between the RCDLR ignition mode data signal circuit at the ignition mode switch connector and a good ground. Does the test lamp illuminate? | Go to Step 15 | Go to Step 13 | |
| 13 | Measure the voltage between the RCDLR ignition mode data signal circuit and the RCDLR ignition mode ground circuit at the ignition mode switch connector. Is the voltage measured within the specified range? | B+ | Go to Step 17 | Go to Step 16 |
| 14 | Disconnect the RCDLR. Test the ignition mode data signal circuit of the RCDLR for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 19 | |
| 15 | Disconnect the RCDLR. Test the ignition mode data signal circuit of the RCDLR for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 19 | |
| 16 | Disconnect the RCDLR. Test the ignition mode ground circuit of the RCDLR for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 19 | |
| 17 | While measuring the resistance between the RCDLR ignition mode data signal and RCDLR ignition mode ground circuits at the ignition mode switch press the ACC/OFF button of the ignition mode switch. Is the value measured approximately as specified? | 2,000 ohms | Go to Step 18 | Go to Step 23 |
| 18 | While measuring the resistance between the RCDLR ignition mode data signal and RCDLR ignition mode ground circuits at the ignition mode switch press the START button of the ignition mode switch. Is the value measured approximately as specified? | 0 ohms | Go to Step 19 | Go to Step 23 |
| 19 | Inspect for poor connections and terminal tension at the harness connector of the RCDLR module. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 20 | |
| 20 | Replace the RCDLR module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 25 | ||
| 21 | Inspect for poor connections and terminal tension at the harness connector of the IPM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 22 | |
| 22 | Replace the IPM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 25 | ||
| 23 | Inspect for poor connections and terminal tension at the harness connector of the ignition mode switch. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 24 | |
| 24 | Replace the ignition mode switch. Refer to Ignition Switch Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 25 | ||
| 25 | Reconnect all components. Use the scan tool in order to clear the DTC. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset? | Go to Step 3 | System OK | |
DTC B1440
Circuit Description
The instrument panel module (IPM) interfaces with an 8-position steering wheel resistive ladder. These switches are used for entertainment purposes and cruise control purposes if the vehicle is equipped with adaptive cruise control. The steering wheel switch network is fed by the remote radio control head ACC supply voltage. The return signal to the IPM is provided by steering column radio control signal circuit. The output voltage must be read by an A/D in order to carry out a ratiometric read which will be used to determine which, if any, switch has been activated.
DTC Descriptor
This diagnostic procedure supports the following DTC
DTC B3622 Steering Wheel Controls Signal Circuit
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.
| DTC Symptom | DTC Symptom Descriptor |
|---|---|
| 01 | Short to Battery |
| 08 | Signal Invalid |
| 59 | Circuit Protection Time-Out |
DTC B3622
Conditions for Running the DTC
- Voltage supplied to the module is in the normal operating voltage range of 9-16 volts.
- IPM in Accessory, Run or Crank power modes.