NOTE: The following table is used to verify voltage at the Pass Key Decoder Module connector with the connector disconnected and the ignition switch in the "RUN" position.

PASS KEY DECODER MODULE TEST (TABLE 1A)

Measure Between	Correct Voltage	For Diagnosis
A1 (PNK/BLK) & GROUND	BATTERY	See 1
B8 (ORN) & GROUND	BATTERY	See 2
A1 (PNK/BLK) & B1 (BLK/WHT)	BATTERY	See 3
A2 (DK BLU) & B1 (BLK/WHT)	5 Volts	See 4

NOTE: The following table continues to verify voltage at the Pass Key Decoder Module connector with the connector disconnected and the ignition switch in the "START" position.

PASS KEY DECODER MODULE TEST (TABLE 1B)

Measure Between	Correct Voltage	For Diagnosis
A3 (DK GRN) & GROUND	BATTERY	See Step 5).
* If voltages are correct, go to PASS KEY DECODER MODULE TEST 2 .

Check the PNK/BLK (439) wire and ENG CNL Fuse for an open.
Check the ORN (440) wire and VATS Fuse for an open.
Check the BLK/WHT (450) wire for an open.
Check the DK BLU (229) wire for an open. If wire is good, replace ECM.
Check DK GRN (965) wire for an open. If wire is good, do PASS KEY DECODER MODULE TEST .

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Pass Key Decoder Module Test 1

Use the Manual With the Right Hardware

When to See a Mechanic