The IPM does not react to any switch inputs of equal or lower priority. If 2 switches are closed at the same time the IPM will read the least resistive path, so that switch takes precedence over the other one.
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 following are the correct resistance value ranges and counts displayed by IPM. The counts displayed by the scan tool proportionally vary with battery voltage.
| Switch Function | Resistance Value Range (ohms) | Counts at 14 volts battery voltage |
|---|---|---|
| Steering column radio control signal circuit short to B+ | 254-255 | |
| Mute/Gap (+) | 1248-1292 | 204-243 |
| Source/Gap (-) | 1537-1591 | 174-203 |
| Voice Req. | 1879-1945 | 147-173 |
| Preset Seek | 2346-2428 | 118-146 |
| Vol. Up | 3048-3156 | 92-117 |
| Vol Dn. | 4208-4356 | 65-91 |
| Seek Up | 6537-6767 | 38-64 |
| Seek Dn. | 13397-13876 | 12-37 |
| No Switch Active | Infinity | 0-11 |
DTC B3622
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Cruise Control Schematics in Cruise Control Connector End View Reference: Cruise Control Connector End Views in Cruise Control and Computer/Integrating Systems Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | IMPORTANT: The Steering Wheel Controls Return parameter proportionally varies with battery voltage. They will not necessarily follow the values from the table. Turn ON the ignition, with the engine OFF. Observe the Steering Wheel Controls Return parameter under instrument panel module (IPM) Data Display>Inputs. Compare the parameter values with the values provided in Diagnostic Aids for every switch position. Are all the values correct? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | CAUTION: Refer to SIR Caution in Cautions and Notices. Turn OFF the ignition. Disconnect the steering wheel control switch assembly. Measure the resistance between the remote radio control head ACC supply voltage circuit and the steering column radio control signal circuit, at the steering wheel control switch. While measuring the resistance, press each of the steering wheel control switches. Does the resistance toggle between infinite and the range specified in Diagnostic Aids for each switch? | Go to Step 4 | Go to Step 8 |
| 4 | Disconnect the IPM. Test the steering column radio control signal circuit for a short to voltage or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 5 |
| 5 | Test the remote radio control head ACC supply voltage circuit for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 6 |
| 6 | 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 10 | Go to Step 7 |
| 7 | Replace the IPM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 10 | |
| 8 | Inspect for poor connections at the harness connector of the steering wheel control switch assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
| 9 | Replace the steering wheel control switch assembly. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 10 | |
| 10 | 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 |
| IMPORTANT |
|---|
| The Steering Wheel Controls Return parameter proportionally varies with battery voltage. They will not necessarily follow the values from the table. |
| CAUTION |
|---|
| Refer to SIR Caution in Cautions and Notices. |
DTC B3622
Circuit Description
Modules connected to the GMLAN serial data circuit monitor for serial data communications on the GMLAN network during normal vehicle operation. Operating information and commands are exchanged among the modules. Each module on GMLAN network maintains a transmit error counter (TEC) and a receive error counter (REC). The counter values increase with detected errors and will decrease with error-free messages. If the TEC value exceeds 255 the controller removes itself from the network and a DTC U0001 will be set.
DTC Descriptor
This diagnostic procedure supports the following DTC
DTC U0001 High Speed CAN Communication Bus
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to Symptoms - Vehicle in Vehicle DTC Information.
| DTC Symptom | DTC Symptom Descriptor |
|---|---|
| 01 | Short to Battery |
DTC U0001