DTC B1785 or B2030. GMC Truck Envoy

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2002 🢒 Envoy - 2WD 🢒 Body and Accessories 🢒 Seats 🢒 DTC B1785 or B2030

Circuit Description

The seat module uses two control circuits to command the seat back reclining motor. The seat module can apply battery positive voltage or a ground to either control circuit. The seat module, based upon switch input, will change the polarity of the control circuits as necessary to achieve the desired seat position.

Conditions for Running the DTC

The seat module must be powered with 9-16 volts.

Conditions for Setting the DTC

If the seat module detects that there is an open, a short to ground or a short to battery positive voltage on either control circuit while they are inactive, the seat module will set the DTC. If the seat module detects less than 1amp draw or a short to ground when the control circuit is active the DTC will set.

Action Taken When the DTC Sets

The seat module will disable the seat from movement, the Memory Recall and Easy Exit Function.

Conditions for Clearing the DTC

•	The DTC will clear when the seat module no longer detects a fault.

•	A history DTC will be cleared after completing 100 consecutive ignition cycles.

Diagnostic Aids

If the DTC is only found in history, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step	Action	Yes	No
Schematic Reference: Power Seats Schematics
1	Did you perform the Power Seat Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Power Seat Systems
2	Install a scan tool. Observe the seat adjuster switch parameter for which the DTC has set in the DSM data list. Does the scan tool display inactive?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Disconnect the seat adjuster switch connector. Observe the seat adjuster switch parameter in the DSM data list. Does the scan tool display inactive?	Go to Step 5	Go to Step 4
4	Test the seat switch signal circuits which set the DTC for an open, a short to ground or a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 6
5	Replace the seat adjuster switch. Refer to Power Seat Switch Replacement . Is the repair complete?	Go to Step 7	--
6	Replace the seat module. Refer to Memory Seat Control Module Replacement . Did you complete the replacement?	Go to Step 7	--
7	Use the scan tool in order to clear the DTCs. Operate the system in order to verify the repair. Does the DTC reset?	Go to Step 2	System OK