GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1420: Device Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Power Sliding Door Module B+

B1292, B1395

B1292, B1395

--

--

Left/Right Sliding Door Open/Close Switch Signal

2

2

2

--

Left/Right Door Enable Switch Signal

1, 2

--

2

--

Left/Right Sliding Door Latch Motor Control

1

1

1

--

Park/Neutral Position Park Signal

--

1

--

--

Left/Right Sliding Door Clutch Control

B1292, B1293, B1294

B1292, B1293, B1294

B1293

--

Left/Right Sliding Door Motor Open Control

B1292

B1292

B1292

--

Left/Right Sliding Door Motor Close Control

B1292

B1292

B1292

--

Left/Right Sliding Door Detent Switch Signal

1

B1294

1

--

Left/Right Sliding Door Sensor Voltage Reference

1

B1395

1

--

Left/Right Sliding Door Sensor Low Reference

1

B1395

1

--

Left/Right Sliding Door Sensor 1 Signal

1

B1395

1

--

Left/Right Sliding Door Sensor 2 Signal

1

B1395

1

--

Left/Right Sliding Door Clutch Ground

--

B1292, B1293, B1294

1

--

PSDM Ground

--

1

1

--

1. Power Sliding Door Malfunction

2. Power Sliding Door Open/Close Switch Inoperative

Circuit/System Description

The body control module (BCM) and the left and right power sliding door modules (PSDM) monitor the battery voltage through the B+ circuit. Damage to components and incorrect data may occur when the voltage is out of range.

Conditions for Running the DTC

Battery voltage must be less than 9 volts or greater than 15.9 volts.

Conditions for Setting the DTC

While attempting the power sliding door OPEN or CLOSE command, the PSDM detects the power sliding door (PSD) system voltage is below 9 volts or above 15.9 volts for greater than 5 seconds.

Action Taken When the DTC Sets

The power sliding door(s) will be inoperative

Conditions for Clearing the DTC

    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present, the DTC will be a history DTC.
    • A history DTC will clear after 50 ignition cycles.

Diagnostic Aids

DTC B1292, B1293, B1294, B1395, B1420, B3250, B3260 or any combination of these DTCs may be set due to an overcinch condition in which the sliding door motor may continue to run for up to 3 seconds after the door is fully closed. Reference any power sliding door overcinching bulletins first before performing any extensive power sliding door diagnostics.

Reference Information

Schematic Reference

Sliding Door Schematics

Connector End View Reference

Vehicle Access Connector End Views

Description and Operation

Power Sliding Door (PSD) Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification

Ignition ON, observe the scan tool Battery Voltage Signal parameter while commanding the power sliding door to OPEN and CLOSE by using the power sliding door switch. The parameter should be between 9.6-13.6 volts.

Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the appropriate PSDM.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 6 and ground.
  3. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Verify that a test lamp illuminates between the B+ circuit terminal 14 and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.