DTC P1381 Misfire Detected - No Communication with Brake Control Module. GMC Truck Savana 1999

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 Savana 🢒 DTC 🢒 DTC P1381 Misfire Detected - No Communication with Brake Control Module

FIGURE - G Van DLC Comp Loc
Cell 23: PWR, GND and DLC
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

This diagnostic will detect a loss of serial communication from the electronic brake control module (EBCM) to the control module. This serial communication is essential in order to distinguish misfire from a rough road condition.

Conditions for Running the DTC

•	The vehicle speed is more than 1 mph

•	The engine speed is less than 5800 RPM

•	The engine load is less than 89%

•	A misfire condition is detected

Conditions for Setting the DTC

A serial data malfunction is preventing the VCM from receiving rough road detection data.

Action Taken When the DTC Sets

•	The control module stores the DTC in history after the first failure but will not illuminate the malfunction indicator lamp (MIL).

•	The control module records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

•	A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles.

•	A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle.

•	Use the scan tool Clear Information function.

Diagnostic aids

Check for the following conditions:

An intermittent may be caused by any of the following conditions:

•	A poor connection

•	Rubbed through wire insulation

•	A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

This step isolates an open serial data circuit from the EBCM system.

Step	Action	Value(s)	Yes	No
1	Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure Records for reference. The control module's data is deleted once the Clear Info function is used. Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?	--	Go to Step 2	Go to the Powertrain On Board Diagnostic (OBD) System Check
2	Check for any U-Codes. Did you find any U-Codes?	--	Go to te applicable DTC table	Go to Step 3
3	Disconnect the VCM and EBCM. Check the serial data circuit between the VCM and the EBCM for an open. Did you find a problem?	--	Go to Step 4	Go to Diagnostic System Check - ABS in Antilock Brake System
4	Repair the circuit as necessary. Refer to Wiring Repairs or Connector Repairs in Wiring Systems. Is the action complete?	--	Go to Step 5	--
5	Using the scan tool, clear the DTCs. Start the engine. Allow the engine to idle until the engine reaches normal operating temperature. Select the DTC and the Specific DTC function. Enter the DTC number which was set. Operate the vehicle with the Conditions for Setting this DTC, until the scan tool indicates the diagnostic Ran. Does the scan tool indicate the diagnostic Passed?	--	Go to Step 6	Go to Step 2
6	Does the scan tool display any additional undiagnosed DTCs?	--	Go to the Applicable DTC Table	System OK