GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 GMC P42 Commercial Chassis 🢒 Body and Accessories 🢒 Instrument Panel, Gauges, and Console 🢒 Low Coolant Indicator Does Not Turn On

Low Coolant Indicator Does Not Turn On P72

P72 Engine Coolant Level Indicator Inaccurate

Step

Action

Value(s)

Yes

No

1

Does the engine coolant level indicator come on when the engine coolant level is low?

--

Go to Step 2

Go to Step 3

2
  1. Check the engine coolant level.
  2. Top off the engine coolant level if necessary.

Does the engine coolant level indicator go out when the engine coolant level is correct?

--

System OK

Go to Step 6

3
  1. Disconnect the engine coolant level indicator probe connector.
  2. Place the ignition switch in RUN.
  3. Connect a fused jumper wire from the engine coolant level indicator probe connector to the ground.

Does the engine coolant level indicator lamp come on?

--

Go to Step 4

Go to Step 5

4

Replace the engine coolant level indicator probe,

Is the repair complete?

--

Go to Step 1

--

5
  1. Locate the open in the YEL/BLK (68) wire between the engine coolant level indicator probe connector and the engine coolant level indicator light.
  2. Repair or replace the wire.

Is the repair complete?

--

Go to Step 1

--

6

With the engine coolant level indicator probe disconnected and the ignition switch in RUN, observe the engine coolant level indicator light.

Does the engine coolant level indicator lamp stay on?

--

Go to Step 5

Go to Step 4

Low Coolant Indicator Does Not Turn On P92

P92 Engine Coolant Level Indicator Inaccurate

Step

Action

Value(s)

Yes

No

1

Does the engine coolant level indicator come on when the engine coolant level is low?

--

Go to Step 2

Go to Step 3

2
  1. Check the engine coolant level.
  2. Top off the engine coolant level if necessary.

Does the engine coolant level indicator go out when the engine coolant level is correct?

--

System OK

Go to Step 6

3
  1. Disconnect the engine coolant level indicator probe connector.
  2. Place the ignition switch in RUN.
  3. Connect a fused jumper wire from the engine coolant level indicator probe connector to the ground.

Does the engine coolant level indicator lamp come on?

--

Go to Step 4

Go to Step 5

4

Replace the engine coolant level indicator probe.

Is the repair complete?

--

Go to Step 1

--

5
  1. Locate open in the WHT (306) wire between the engine coolant level indicator probe connector and the engine coolant level indicator light.
  2. Repair or replace the wire.

Is the repair complete?

--

Go to Step 1

--

6

With the engine coolant level indicator probe disconnected and the ignition switch in RUN, observe the engine coolant level indicator light.

Does the engine coolant level indicator lamp stay on?

--

Go to Step 5

Go to Step 4