DTC P1671 Malfunction Indicator Lamp (MIL) Control Circuit. Oldsmobile Intrigue 1999

For 1990-2009 cars only

Makes 🢒 Oldsmobile 🢒 1999 🢒 Intrigue 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 DTC P1671 Malfunction Indicator Lamp (MIL) Control Circuit

Engine Controls Components
Power, Ground, DLC and MIL
OBD II Symbol Description Notice

Circuit Description

Output driver modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding on. Unlike the quad driver modules (QDMs) used in prior model years, ODMs have the capability of diagnosing each output circuit individually. A DTC P1671 set indicates an improper voltage level on the output circuit which controls the malfunction indicator lamp (MIL).

Conditions for Setting the DTC

•	The ignition is on.

•	An improper voltage level has been detected on the MIL control circuit.

•	The above conditions are present for at least 30 seconds.

Action Taken When the DTC Sets

The PCM stores the conditions which were present when the DTC set as Fail Records data only.

Conditions for Clearing the MIL/DTC

•	A history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared using the scan tool Clear Info function or by disconnecting the PCM battery feed.

Diagnostic Aids

Inspect for the following conditions:

•	A faulty connection at the PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection.

•

Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM, turn the ignition on, and observe a digital multimeter connected between the MIL control circuit and ground at the PCM harness connector while moving the connectors and the wiring harnesses related to the MIL. A change in voltage indicates the location of the malfunction.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description

The number(s) below refer to the step number(s) on the Diagnostic Table.

Normally, ignition feed voltage should be present on the control circuit with the powertrain control module (PCM) disconnected and the ignition turned on.

Checks for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is causing an open circuit while being operated, resulting in a measured current of 0 milliamps.

Checks for a short to voltage on the control circuit.

This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read-only memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

DTC P1671 - MIL Control Circuit

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	Turn the ignition switch to the OFF position. Disconnect the PCM. Turn the ignition switch to the ON position. Use a digital multimeter (DMM) in order to measure the voltage between the malfunction indicator lamp (MIL) control circuit and ground at the PCM harness connector. Is voltage near the specified value?	B+	Go to Step 3	Go to Step 6
3	Use the DMM in order to measure the current between the MIL control circuit and ground at the PCM harness connector. Monitor the current reading on the digital multimeter for at least 2 minutes. Does the current reading remain between the specified values?	0.05-0.5 amps 50-500 mA	Go to Step 11	Go to Step 4
4	Turn the ignition switch to the OFF position. Disconnect the instrument panel. Leave the PCM disconnected. Turn the ignition switch to the ON position. Use the DMM in order to measure the voltage between the MIL control circuit and ground. Does the voltage equal the specified value?	0 V	Go to Step 10	Go to Step 5
5	Locate and repair a short to voltage in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	--	Go to Step 15	--
6	Inspect the ignition feed fuse for the instrument panel indicators. Is the fuse open?	--	Go to Step 7	Go to Step 8
7	Locate and repair a short to ground in ignition feed circuit for the instrument panel indicators. Refer to Wiring Repairs in Wiring Systems. Replace the fuse. Did you complete the repair?	--	Go to Step 15	--
8	Disconnect the instrument cluster. Turn the ignition switch to the ON position. Measure the voltage between the ignition feed circuit for the instrument cluster indicators and ground. Is voltage near the specified value?	B+	Go to Step 9	Go to Step 13
9	Test the MIL control circuit for an open or a short to ground. If a problem is found, repair the circuit. Refer to Wiring Repairs in Wiring Systems. Was a problem found?	--	Go to Step 15	Go to Step 10
10	Inspect the MIL control circuit and the instrument panel indicators ignition feed circuit for a faulty connection at the instrument panel and at the PCM. If a problem is found, replace the loose terminal(s). Refer to Connector Repairs in Wiring Systems. Was a problem found?	--	Go to Step 15	Go to Instrument Panel in Engine Electrical
11	Turn the ignition switch to the OFF position. Reconnect the PCM. Disconnect the instrument cluster. Turn the ignition switch to the ON position. Connect a test lamp between the MIL control circuit and the ignition feed circuit at the instrument panel harness connector. Use the scan tool outputs test function in order to cycle the MIL on and off. Does the test lamp flash?	--	Go to Diagnostic Aids	Go to Step 12
12	Inspect the MIL control circuit for a faulty connection at the PCM. If a problem is found, replace the loose terminal. Refer to Connector Repairs in Wiring Systems. Was a problem found?	--	Go to Step 15	Go to Step 14
13	Locate and repair an open in the ignition feed circuit to the instrument panel indicators. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	--	Go to Step 15	--
14	Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the repair?	--	Go to Step 15	--
15	Review and record the scan tool Fail Records data. Clear any DTCs. Operate the vehicle within the Fail Records conditions. Use the scan tool in order to monitor the Specific DTC info for DTC P1671. Does the scan tool indicate DTC P1671 Failed This Ign?	--	Go to Step 2	System OK