For 1990-2009 cars
ABS Components
ABS/ETS Schematics

### Circuit Description

Two-way serial communication is sent back and forth between the EBCM and the IPC. A message from the IPC is sent to the EBCM within seven seconds after ABS initialization. A serial communication failure does not allow the proper warning indicator commands to be sent back to the IPC. Refer to ABS/ETS System Description .

### Diagnostic Aids

The scan tool Serial Data Link (SDL) monitor used in this diagnostic is within the body portion of the scan tool. This requires exiting from the chassis portion of the scan tool to the main menu and entering into the body portion of the scan tool menu and selecting SDL MONITOR.

With the SDL monitor (ABS to IPC mode), any message that is being transmitted on the serial data link can be observed. Refer to Instrument Panel luster for further serial data link information.

The frequency of the malfunction can be checked by using the ENHANCED DIAGNOSTIC function of the scan tool, as described in Enhanced Diagnostics, found in this section.

The following conditions may cause an intermittent malfunction:

• | A poor connection

• | Rubbed-through wire insulation

• | A broken wire inside the insulation

Use the Lamp Test function of the Scan Tool in order to turn the indicator on while looking for an intermittent malfunction in the ETS OFF warning indicator circuitry.

Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:

• | Backed out terminals

• | Improper mating

• | Broken locks

• | Improperly formed or damaged terminals

• | Poor terminal-to-wiring connections

• | Physical damage to the wiring harness

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 |

1. Turn the ignition switch to the OFF position.
2. Install a Scan Tool .
3. Turn the ignition switch to the RUN position.
4. Select Special Functions on the Scan Tool .
5. Select Lamp Test on the Scan Tool .
6. Use the Scan Tool in order to turn the amber ETS OFF warning indicator on.

Did the amber ETS OFF warning indicator turn on?

--

Go to Step 3

Go to Step 4

3 |

1. Select Special Functions on the Scan Tool .
2. Select Lamp Test on the Scan Tool .
3. Use the Scan Tool in order to flash the amber ETS OFF warning indicator on and off.

Did the amber ABS warning indicator flash?

--

Go to Step 7

Go to Step 4

4 | Inspect all of the connectors and the terminals for the following conditions:

• | Poor terminal contact

• | Evidence of corrosion

Is there evidence of poor terminal contact or corrosion?

--

Go to Step 5

Go to Step 6

5 | Replace all of the terminals that exhibit signs of poor terminal contact or corrosion. Refer to Troubleshooting Procedures, Cell 4 in Electrical Diagnosis. Is the repair complete? | -- | Go to Diagnostic System Check | --
6 | Repair the instrument panel cluster. Refer to Instrument Cluster, Cell 80 in Electrical Diagnosis. Is the repair complete? | -- | Go to Diagnostic System Check | --
7 | The malfunction is not present at this time. Refer to Diagnostic Aids for more information. Is the action complete? | -- | System OK | --