P2161-VEHICLE SPEED SENSOR 2 ERRATIC (with ABS)

For a complete wiring diagram Refer to Section 8W.

When Monitored:
With engine run time greater than 5 seconds, ECT above –8° C (17.6° F), transmission not in park or neutral, brakes not applied, engine rpm greater than 1500, and no ECT, MAP, TPS, ETC, or brake switch stuck DTCs present.
Set Condition:
The PCM receives an erratic vehicle speed signal. One Trip Fault. Three good trips to turn off the MIL.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Diagnostic Test

1. ACTIVE DTC

NOTE: Diagnose and repair any communication DTCs before continuing with this test.

NOTE: Diagnose and repair any DTCs set in the ABS Module before continuing with this test.

NOTE: Verify that the correct Pinion Factor and tire size are programmed into the ABS module before continuing. If necessary, update and retest.

Start the engine and allow it to reach operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set.

With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

Go to 2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2. TIRE INSPECTION

NOTE: This DTC can set as a result of excessive wheel speed variation, caused by unequal tire circumference or by front or rear wheels slipping (on loose gravel or ice, due to hard acceleration, etc.)

Inspect all tires for proper inflation and excessive wear.
Review Freeze Frame information to determine road and driving conditions when the fault set.

Were any problems found?

Yes

Repair as necessary. If the DTC set during a front or rear wheel spin condition, no repair is necessary.

Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go to 3

3. POWERTRAIN CONTROL MODULE (PCM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Anti-lock Brake Module and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.

Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace the Powertrain Control Module (PCM) in accordance with the Service Information.
Perform the PCM Verification Test. (Refer to 9 - ENGINE - STANDARD PROCEDURE)