DTC P1662 Cruise Lamp Control Circuit. Cadillac Catera 1999

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 1999 🢒 Catera 🢒 DTC 🢒 DTC P1662 Cruise Lamp Control Circuit

Handling ESD Sensitive Parts Notice
Engine Controls Components
Cell 20: Cruise Control
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The ECM turns the CRUISE lamp on whenever actual cruise operation is present. The ECM controls the lamp by grounding the control circuit with an internal solid state device called a driver.

Conditions for Running the DTC

•	The battery voltage is between 7.5-15 volts.

•	The engine speed is more than 40 RPM.

•	The cruise control is engaged.

Conditions for Setting the DTC

The ECM detects an open, a short to voltage, or a short to ground on the Cruise lamp control circuit.

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 40 consecutive warm up cycles in which no failures are reported by this diagnostic or any other non-emission related diagnostic.

•	The ECM battery voltage is interrupted.

•	The scan tool clears the MIL/DTC.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

The CRUISE lamp should remain OFF when the ignition is turned ON and the engine is OFF.

If the other indicator lamps in the instrument cluster are functioning, the feed circuit is OK.

If the CRUISE lamp is ON with the ECM connected and OFF with the ECM disconnected there is a problem in the ECM.

If the CRUISE lamp is OFF with the ECM disconnected and a short to ground is NOT present on the control circuit the fault is within the instrument panel.

After cruise is engaged, the CRUISE indicator lamp should illuminate.

DTC P1662 Cruise Lamp Control Circuit

Step

Action

Values

Yes

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

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Turn ON the ignition, leaving the engine OFF.

Is the CRUISE indicator OFF?

Go to Step 3

Go to Step 6

Check the fuse for the instrument cluster ignition feed circuit.

Is the fuse OK?

Go to Step 4

Go to Step 9

Turn OFF the ignition.
Disconnect the ECM.
Turn ON the ignition.
Use a fused jumper in order to jumper the CRUISE indicator control circuit in the ECM harness connector to ground.

Is the CRUISE indicator ON?

Go to Step 10

Go to Step 5

Check for the following conditions:

•	A damaged bulb, refer to Wiring Repairs in Wiring Systems.

•	An open ignition feed to the bulb, refer to Wiring Repairs in Wiring Systems.

•	A control circuit open or shorted to B+, refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 12

Command the CRUISE indicator OFF using the scan tool.

Does the CRUISE indicator turn OFF?

Go to Step 11

Go to Step 7

Turn OFF the ignition.
Disconnect the ECM.
Turn ON the ignition with the engine OFF.

Is the CRUISE indicator ON?

Go to Step 8

Go to Step 10

Repair the short to ground in the CRUISE control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 12

Repair the short to ground in the feed circuit to the instrument panel indicator lamps. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 12

Check for a poor connections or poor terminal tension at the ECM harness connector. Refer to Engine Control Module Diagnosis for proper procedure.

Did you find and correct a problem?

Go to Step 12

Go to Step 11

Important:

•	Perform the Idle Learn Procedure when replacing the ECM or throttle body.

•	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 12

Using the scan tool, clear the DTCs.
Operate the vehicle within the Conditions for Running this DTC.
Operate the vehicle with cruise engaged.

Does the scan tool indicate that the diagnostic Passed?

System OK

Go to Step 2