GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Montana 🢒 Engine 🢒 Engine Electrical 🢒 Ignition Relay Diagnosis

Circuit Description

The ignition relay supplies battery positive voltage to the following components:

    • Fuel injectors
    • Ignition control module
    • Heated oxygen sensors (HO2S)
    • A/C CLU relay
    • Mass air flow sensor
    • Evaporative emission (EVAP) solenoid
    • Air pump relay
    • Transmission solenoids

Diagnostic Aids

If the ignition relay fails to close:

    • Engine will crank, but does not run.
    • Instrument panel lights will illuminate.
    • Scan data will be available.

Test Description

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

  1. This step is testing the battery positive voltage circuit of the ignition relay.

    2.

  2. This step is testing the ignition 1 positive voltage circuit of the ignition relay.

    3.

  3. This step is testing the coil ground circuit of the ignition relay.

    4.

  4. This step isolates the circuit from the ignition relay. All of the circuits at the relay are good if the test lamp illuminates.

Step

Action

Value(s)

Yes

No

Schematic Reference: Power Distribution Schematics and Ground Distribution Schematics in Wiring Systems.

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Turn OFF the ignition.
  2. Remove the underhood fuse relay center cover.
  3. Remove the ignition relay with the J 43244 Relay Puller Pliers.
  4. Probe the battery positive voltage circuit for the ignition relay at the underhood fuse block with the test lamp connected to a good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 10

3

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit for the ignition relay at the underhood fuse block with the test lamp connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 6

4

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the coil ground circuit for the ignition relay at the underhood fuse block, with a test lamp connected to 12 volts.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Jumper the ignition relay battery positive voltage circuit and the ignition relay load circuit together at the underhood fuse block, using a fused jumper wire. Refer to Using Fused Jumper Wires in Wiring Systems.

    3. Important: At least one test point of each fuse must illuminate the test lamp.

  3. Probe the following fuses with the test lamp connected to a good ground.
    4. • IGN 1
    • ELEC IGN
    • INJ

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 10

6
  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable at the battery.
  3. Disconnect the underhood fuse block electrical connectors.
  4. Test the ignition 1 voltage circuit of the ignition relay at the underhood fuse block electrical connector for an open circuit or a short to ground. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

7
  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable, at the battery.
  3. Disconnect the underhood fuse block electrical connectors.
  4. Test the coil ground circuit of the ignition relay at the underhood fuse block electrical connector, for an open circuit. Refer to Testing for Continuity in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

8

Inspect for poor terminal contact at the ignition relay connector position of the underhood fuse block Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find a condition?

--

Go to Step 10

Go to Step 9

9

Replace the ignition relay.

Did you complete the replacement?

--

Go to Step 11

--

10

Important: Do not disassemble or attempt any repairs to the underhood fuse block.

Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the replacement?

--

Go to Step 11

--

11
  1. Remove all test equipment.
  2. Connect any disconnected components, fuses, etc.
  3. Turn OFF ignition for 30 seconds.
  4. Start the engine and operate the vehicle.
  5. Observe the MIL, vehicle performance and driveability.

Does the vehicle operate normally, with no MIL illumination and no stored DTCs?

--

System OK

Go to Diagnostic Trouble Code (DTC) List