GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy C Pickup - 2WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Manual Transmission Shift Light

Object Number: 32861 Size: MF
Engine Controls Components
4.3L VCM, I/C, IAC
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The control module controls the shift lamp using the following inputs:

    • The Engine Coolant Temperature (ECT) sensor
    • The Throttle Position (TP) sensor
    • The Vehicle Speed sensor (VSS)
    • The Engine RPM

The control module uses the measured RPM and the vehicle speed in order to calculate what gear the vehicle is in. This calculation determines when the shift lamp should be turned ON.

Test Description

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

  1. This step checks the control module's ability to control the shift lamp.

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Turn ON the ignition.
  4. Command the shift lamp ON with the scan tool.

Is the shift lamp ON?

--

Go to Step 4

Go to Step 3

3
  1. Disconnect the control module connector that contains the shift lamp control circuit.
  2. Turn ON the ignition.
  3. Connect a fused jumper between the shift lamp control circuit and ground.

Is the shift lamp ON?

--

Go to Step 5

Go to Step 6

4

Command the shift lamp OFF and ON with the scan tool.

Does the shift lamp respond to the scan tool command?

--

System OK

Go to Step 8

5

Check the terminal connect at the control module for the shift lamp control circuit.

Was a problem found?

--

Go to step 7

Go to Step 10

6

Repair the open in the shift lamp circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 11

--

7

Repair as necessary.

Is the action complete?

--

Go to Step 11

--

8
  1. Turn OFF the ignition.
  2. Disconnect the control module connector that contains the shift lamp control circuit.
  3. Turn ON the ignition.

Is the shift lamp ON?

--

Go to Step 9

Go to Step 10

9

Repair the short to ground in the shift lamp control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 11

--

10
  1. Replace the VCM.
  2. Program the new VCM. Refer to VCM Replacement/Programming .
  3. Perform the VTD Password Learn Procedure. Refer to Password Learn .
  4. Perform the CKP System Variation Learning Procedure. Refer to Crankshaft Position System Variation Learn .

Is the action complete?

--

Go to Step 11

--

11
  1. Allow the engine to idle until the engine reaches normal operating temperature.
  2. Select DTC Failed This Ignition.

Are any additional DTCs displayed?

--

Go to the applicable DTC table

Go to Step 12

12

Display the Capture Info and the Review Capture Info function with a scan tool.

Are any new DTCs displayed?

--

Go to the applicable DTC table

System OK