GM Service Manual Online
For 1990-2009 cars only

Object Number: 383823  Size: LF
Engine Controls Component Views
Cell 20: Manual Transmission Controls
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

An ignition voltage is supplied directly to the Reverse Inhibit solenoid. The PCM controls the solenoid by grounding the control circuit via an internal switch called a driver. The driver supplies the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low, near 0 volts. When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status changes, causing the DTC to set.

When the Reverse Inhibit solenoid energizes, the operator can shift the transmission into reverse. The PCM enables the Reverse Inhibit solenoid whenever the vehicle speed is below 5 mph. When the vehicle speed is above 5 mph, the PCM de-energizes the solenoid, which prevents the operator from shifting the transmission into reverse.

Conditions for Running the DTC

    • The engine speed is greater than 400 RPM.
    • Ignition voltage greater than 6 volts but less than 18 volts.

Conditions for Setting the DTC

    • The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
    • All conditions exist for a minimum of 5.0 seconds.

Action Taken When the DTC Sets

    • The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the MIL/DTC

    • A last test failed (current DTC) clears when the diagnostic runs and does not fail.
    • A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • Use a scan tool in order to clear the MIL/DTC.

Diagnostic Aids

Important: 

   • Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
   • For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616 . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

    • Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.
    • Low system voltage can cause this DTC to set. When reviewing captured data, verify if a low system voltage condition was present at the time the DTC was stored in memory.
    •  For an intermittent, refer to Symptoms .

Test Description

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

  1. Listen for an audible click when the solenoid operates. Command both the ON and the OFF states. Repeat the commands as necessary.

  2. This test can detect a partially shorted coil which would cause excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When warm the coil may open (Amps drop to 0), or short (goes above 0.75 amp).

  3. Listen for an audible click when the relay operates. Ground the circuit as necessary.

  4. If you find no trouble in the control circuit or the connection at the PCM, the PCM may be faulty. However, this is an extremely unlikely failure.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn ON the ignition leaving the engine OFF.
  2. Command the solenoid ON and OFF using a scan tool.

Does the solenoid turn ON and OFF when commanded?

--

Go to Step 3

Go to Step 5

3

  1. Turn OFF the Ignition.
  2. Disconnect the PCM connector C2 located on the opposite side of the manufacturer's logo. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement .
  3. Turn ON the ignition.
  4. Measure the current from the solenoid control circuit in the PCM harness connector to ground for 2 minutes using the DMM J 39200 on the 40 amp scale.
  5. Important: Replace the solenoid if the DMM goes to 0 amps during the current draw test.

Does the Current draw measure less than the value shown (but not 0)?

1.5A

Go to Diagnostic Aids

Go to Step 4

4

  1. Turn OFF the Ignition.
  2. Disconnect the solenoid.
  3. Measure the resistance from the solenoid control circuit in the PCM harness connector to ground using the DMM J 39200 .

Does the DMM display infinite resistance?

--

Go to Step 12

Go to Step 10

5

  1. Turn OFF the Ignition.
  2. Disconnect the solenoid.
  3. Connect the test lamp J 35616-200 between the terminals in the solenoid harness connector.
  4. Turn ON the ignition.
  5. Command the solenoid ON and OFF using a scan tool.

Does the test lamp turn ON and OFF when commanded?

--

Go to Step 8

Go to Step 6

6

Probe the ignition feed circuit in the solenoid harness connector with the test lamp J 35616-200 connected to ground.

Is the test lamp illuminated?

--

Go to Step 7

Go to Step 11

7

  1. Turn OFF the Ignition.
  2. Reconnect the solenoid.
  3. Disconnect the PCM connector C2 located on the opposite side of the manufacturer's logo. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement .
  4. Turn ON the ignition.
  5. Momentarily probe the solenoid control circuit in the PCM harness connector with a fused jumper wire connected to a ground. Refer to Probing Electrical Connectors and Using Fused Jumper Wires in Wiring Systems.

Does the solenoid turn ON when the control circuit is grounded and turn OFF when the circuit is opened?

--

Go to Step 9

Go to Step 10

8

  1. Inspect for a poor connection at the solenoid connector. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
  2. If you find a poor connection repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

9

  1. Inspect for a poor connection at the PCM connector. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
  2. If you find a poor connection repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

10

Repair the solenoid control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 14

--

11

Repair the faulty solenoid ignition feed circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 14

--

12

Replace the solenoid. Refer to Reverse Lockout Solenoid in Manual Transmission.

Is the replacement complete?

--

Go to Step 14

--

13

Important:: Program the replacement PCM. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement .

Replace the PCM.

Is the action complete?

--

Go to Step 14

--

14

  1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC option using the scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
  4. Operate vehicle within the Conditions for Running this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test failed?

--

Go to Step 2

Go to Step 15

15

Select the Capture Info option and the Review Info option using the scan tool.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to the applicable DTC table

System OK