LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2004 >> Optra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 1.6L (L91) - DTC P0336 To DTC P1402 >> DTC P1385 >> Test Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Description

  1. 3:  This step determines if an intermittent condition is current.
  1. 9:  This step determines if the wheel speed sensor is unable to generate the proper voltage.
Step Action Values Yes No
Schematic References: Engine Controls Schematics
Connector End View References: Engine Control Module Connector End Views or Engine Controls Connector End Views
1 Did you perform the Diagnostic System Check - Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2
  1. Start the engine.
  2. Operate the vehicle within the Conditions for Running the DTC.
  3. Observe the DTC Information with a scan tool.
Did DTC P1385 fail this ignition?		 - Go to Step 4  Go to Step 3 
3 
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Does the DTC fail this ignition?		 - Go to Step 4  Go to Diagnostic Aids
4 Is the vehicle equipped with an Anti-Lock Brake System (ABS)? - Go to Step 5  Go to Step 7 
5 Is the ABS lamp ON? - Go to Diagnostic System Check - ABS Go to Step 6 
6
  1. Turn OFF the ignition.
  2. Disconnect the electronic brake control module (EBCM).
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from rough road signal circuit at the EBCM harness connector to a good ground.
Is the voltage within the specified range?		 4.8-5.2 V Go to Step 14  Go to Step 10 
7
  1. Disconnect the wheel speed sensor.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage from the rough road signal circuit of the wheel speed sensor to a good ground with a DMM.
Is the voltage within the specified range?		 4.8-5.2 Volts Go to Step 8  Go to Step 11 
8
  1. Turn OFF the ignition.
  2. Measure the resistance of the low reference circuit of the wheel speed sensor to a good ground with a DMM.
Is the resistance less than the specified value?		 5 Ω Go to Step 9  Go to Step 12 
9 
IMPORTANT: If the wheel speed sensor harness is damaged in any way, DO NOT repair the harness.
    NOTE: Support the lower control arms in the normal horizontal position in order to avoid damage to the drive axles. Do not operate the vehicle in gear with the wheels hanging down at full travel.
  1. Raise and support the drive wheels.
  2. Start and idle the engine.
  3. Engage the transmission into 2nd gear or drive for an automatic.
  4. Turn the DMM to the AC scale.
  5. Measure the voltage between the rough road signal circuit and low reference of the wheel speed sensor at the sensor side with a DMM.
Is the voltage more than the specified value?		 70 mV Go to Step 15  Go to Step 13 
10 Test the rough road signal circuit between the electronic brake control module (EBCM) and the engine control module (ECM) for one of the following conditions:
  • An open
  • A short to ground
  • A short to voltage
  • High resistance

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 19  Go to Step 15 
11 Test the rough road signal circuit of the wheel speed sensor for one of the following conditions:
  • An open
  • A short to ground
  • A short to voltage
  • High resistance

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 19  Go to Step 15 
12 Test the low reference circuit of the wheel speed sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .
 
Did you find and correct the condition?		 - Go to Step 19  Go to Step 15 
13 Test for an intermittent and for a poor connection at the wheel speed sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals .
Did you find and correct the condition?		 - Go to Step 19  Go to Step 16 
14 Test for an intermittent and for a poor connection at the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals .
Did you find and correct the condition?		 - Go to Step 19  Go to Step 17 
15 Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals .
Did you find and correct the condition?		 - Go to Step 19  Go to Step 18 
16 Replace the wheel speed sensor.
Did you complete the replacement?		 - Go to Step 19  -
17 Replace the EBCM. Refer to Brake Pressure Modulator Valve Assembly Replacement .
Did you complete the replacement?		 - Go to Step 19  -
18 Replace the ECM. Refer to Engine Control Module Replacement .
Did you complete the replacement?		 - Go to Step 19  -
19
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 20 
20 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
scientia non olet · About LEMON Manuals