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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Catera 🢒 DTC 🢒 DTC P1502 Theft Deterrent Fuel Enable Signal Not Received

Object Number: 70490 Size: LF
Engine Controls Components
Cell 20: EBTCM and Theft Deterrent Module
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

This DTC will set if the ECM has not been programmed with the frequency code of the Theft Deterrent Module, or if there is a problem with the circuit used for transmitting the data (the Vehicle Speed/Theft Deterrent Signal circuit).

Conditions for Running the DTC

Engine cranking

Conditions for Setting the DTC

The ECM has not received the frequency code from the Theft Deterrent Module.

Action Taken When the DTC Sets

The ECM will not illuminate the malfunction indicator lamp (MIL).

Conditions for Clearing the MIL/DTC
    • The DTC clears after forty consecutive warm-up cycles if no failures report by this diagnostic or any other non-emission related diagnostic.
    • The scan tool clears the MIL/DTC.

Diagnostic Aids

If the ECM and the Theft Deterrent Module have not been properly programmed, this DTC may set and the vehicle will not start. Refer toTheft Deterrent System in Accessories for programming instructions.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step verifies whether or not the ECM is receiving vehicle speed data.

    2.

  2. The test light that is connected to B+ is used to simulate the B+ pull-up within the ECM. The DVM can be connected to the shaft of the test light and battery ground.

DTC P1502 - Theft Deterrent System - No Password Received

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn off the ignition.

    2. Caution: Suitably chock the front wheels in order to prevent any unintended vehicle movement if only the rear of the vehicle is to be lifted in order to prevent vehicle damage and personal injury.

  2. Raise the vehicle in order to lift the drive wheels off the ground.
  3. Turn on the ignition.
  4. Shift the gear selector to neutral.
  5. Rotate the left rear wheel by hand while observing the Vehicle Speed on the scan tool.

Does the scan tool indicate a vehicle speed above the specified value?

0.0 mph/km/h

Refer to Diagnostic Aids

Go to Step 3

3

  1. Turn off the ignition.
  2. Disconnect the ECM.
  3. Connect the test light J 34142-B from B+ to the Vehicle Speed/Theft Deterrent Signal circuit in the ECM connector and leave the test light in place.
  4. Use the DVM J 39200 set to AC, Hz, 4 volt scale, in order to measure the frequency between the vehicle speed/theft deterrent signal circuit in the ECM harness connector and ground.
  5. While monitoring the DVM, turn on the ignition leaving the engine off.

Does the DVM momentarily indicate frequency within the specified range?

100-900 Hz

Go to Step 5

Go to Step 4

4
  1. Turn off the ignition.
  2. Disconnect the Theft Deterrent Module harness connector.
  3. Check the Vehicle Speed/Theft Deterrent Signal Circuit for the following conditions:
    4. • An open circuit
    • A short to ground
    • A short to power

Was a problem found?

--

Go to Step 6

Go to Step 7

5

  1. Turn off the ignition.
  2. Reconnect the ECM.
  3. Disconnect Theft Deterrent Module harness connector.
  4. Connect the Signal Generator Tester J 38522 to the Vehicle Speed circuit in the Theft Deterrent Module harness connector (one terminal connected to the signal circuit and the other terminal connected to ground).
  5. Turn on the ignition.
  6. Turn on the tester and set to 12V, 50% Duty Cycle, 600 Hz.

Does the scan tool indicate the vehicle speed above the specified value?

0.0 mph/km/h

Go to Antilock Brake System (ABS)

Go to Step 8

6

Repair the Vehicle Speed/Theft Deterrent Signal circuit between the Theft Deterrent Module harness connector and the ECM.

Is the action complete?

--

Go to Step 10

--

7

Check for a poor connection or poor terminal tension at the Theft Deterrent Module harness connector. Refer to Electrical Diagnosis in Engine Electrical, and Trouble Shooting Procedures for the proper procedure. Also, refer to Checking Terminal Contact in Engine Control Module Diagnosis .

Was a problem found and corrected?

--

Go to Step 10

Go to Theft Deterrent System

8

Check for a poor connection or poor terminal tension at the ECM harness connector. Refer to Electrical Diagnosis in Engine Electrical, and Trouble Shooting Procedures for the proper procedure. Also, refer to Checking Terminal Contact in Engine Control Module Diagnosis .

Was a problem found and corrected?

--

Go to Step 10

Go to Step 9

9

Important: This vehicle is equipped with a Theft Deterrent System which interfaces with the Engine Control Module (ECM). Program the new ECM with the frequency code of the theft deterrent module that is currently on the vehicle.

Replace the ECM. Refer to Engine Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 10

--

10
  1. Clear the DTCs with the scan tool.
  2. Turn off the ignition for 15 seconds.
  3. Operate the vehicle with the conditions that are required for this vehicle to run. Refer to Conditions for Running the DTC.
  4. Check for any DTCs.

Is this DTC set?

--

Go to Step 2

Go to Step 11

11

Were there any additional DTCs noted during the Powertrain OBD System Check that have not been diagnosed?

--

Go to the applicable DTC table

The System is OK