DTC C0244 or P1689. GMC Truck Savana 2005

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2005 🢒 Savana 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0244 or P1689

Circuit Description

The electronic brake control module (EBCM) supplies approximately 12 volts through an internal resistor to the powertrain control module (PCM) on the delivered torque signal circuit. The PCM toggles this voltage to ground in order to create the delivered torque signal at the EBCM. A signal with a frequency of 128 Hz +/- 5 percent and a duty cycle of 25-95 percent is a valid delivered torque signal. The percentage of duty cycle is proportionate to the percentage of delivered engine torque.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0244 or DTC P1689 Pulse Width Modulated (PWM) Delivered Torque

Conditions for Running the DTC

•	The ignition is ON.

•	The engine is running at a speed greater than 450 RPM for 1 second.

Conditions for Setting the DTC

C0244

The EBCM receives an invalid delivered torque signal for 300 milliseconds.

P1689

The PCM detects open or shorted delivered torque signal voltage as being less than 4.75 volts or greater than 5.25 volts.

Action Taken When the DTC Sets

•	The EBCM disables the vehicle stability enhancement system (VSES).

•	The stability indicator turns ON.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

•	Testing for Electrical Intermittents

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

•	Connector Repairs

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step tests for voltage supplied to the PCM from the EBCM.

This step tests for a shorted resistor in the EBCM or a short to voltage within the circuit, by verifying that a large voltage drop occurs in the circuit when the test lamp is placed in parallel with the DMM. The PCM may be damaged if either of these conditions is present.

Step	Action	Values	Yes	No
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Powertrain Control Module Connector End Views in Engine Controls - 4.8L, 5.3L and 6.0L, and Antilock Brake System Connector End Views
1	Did you performs the Diagnostic System Check - Vehicle?	--	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Use a scan tool in order to clear the DTCs. Turn OFF the ignition for 5 seconds. Start the engine. Does the DTC set?	--	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect from the powertrain control module (PCM), the harness connector containing the delivered torque signal circuit. Turn ON the ignition. Use a DMM in order to measure the voltage between the delivered torque signal circuit and a good ground. Does the voltage measure greater than the specified value?	10 V	Go to Step 4	Go to Step 5
4	With the DMM still connected to monitor the delivered torque signal circuit, connect one end of a test lamp to a good ground. Connect the other end of the test lamp to the positive lead of the DMM, while observing the DMM display. Does the voltage measure less than the specified value?	0.15 V	Go to Step 6	Go to Step 10
5	Test the delivered torque signal circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	--	Go to Step 13	Go to Step 8
6	Turn OFF the ignition. Reconnect the PCM harness connector. Start the engine. Select the vehicle stability enhancement system (VSES) Data Display function on the scan tool. Observe the Delivered Torque parameter on the scan tool. Does the scan tool display a duty cycle of the delivered torque signal within the specified range?	25-95%	Go to Step 7	Go to Step 11
7	Turn OFF the ignition. Install a J 39700 100-Pin Breakout Box and a J 39700-650 Adapter Cable. Install the equipment between the electronic brake control module (EBCM) and the EBCM harness connector. Start the engine. Use a DMM in order to measure the Hz frequency between the delivered torque signal circuit and a ground circuit. Does the Hz frequency of the delivered torque signal measure within the specified range?	121-134 Hz	Go to Step 9	Go to Step 12
8	Turn OFF the ignition. Inspect for poor connections at the harness connector of the EBCM. 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 13	Go to Step 9
9	Important: Following EBCM replacement, perform the set-up procedure for the EBCM and perform the Yaw Rate Reference Table Reset Procedure. Use the scan tool to perform the Tire Size Calibration procedure. Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems. Did you complete the replacement?	--	Go to Step 13	--
10	Test the delivered torque signal circuit 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 13	Go to Step 12
11	Inspect for poor connections at the harness connector of the PCM. 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 13	Go to Step 12
12	Important: Perform the setup procedure for the PCM. Replace the PCM. Refer to Control Module References in Computer/Integrating Systems. Did you complete the replacement?	--	Go to Step 13	--
13	Use the scan tool Clear All Class 2 DTCs function to clear all of the DTCs from all modules. Turn OFF the ignition for 5 seconds. Turn ON the ignition. 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