GM Service Manual Online
For 1990-2009 cars only

Refer to Engine Controls Schematics

I/P and Driver Information Display


Object Number: 588160  Size: FS
Power, Ground and Door Locks
Power/Ground Distribution, Instrument Cluster and DID
Turn Signal Switch, PCM, IPC and Engine Oil Pressure Switch
DRL, Canister, PWR DROP, TURN, SIR, IP-IGN, CRUISE, and ECM Fuse
DRL, Canister, PWR DROP, TURN, SIR, IP-IGN, CRUISE, and ECM Fuse
Instrument Cluster Indicators, MSVA and Stop Lamp Switch
Handling ESD Sensitive Parts Notice
G200 (4 of 4)
G200 (3 of 4)
Handling ESD Sensitive Parts Notice
Engine Controls Components
Powertrain Control Module Description
IAC, I/P, Engine Oil Level Indicator Switch and PNP
MAF, EVAP Purge, EVAP Canister, EGR Valve
OBD II Symbol Description Notice
for a wiring diagram.

Circuit Description

The powertrain control module (PCM) uses the output driver modules (ODMs) in order to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM can control 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 are capable of individually diagnosing each output circuit. DTC P1673 will set an improper voltage level on the output circuit that controls the engine hot lamp.

Conditions for Setting the DTC

    • The ignition is ON.
    • An improper voltage level has been detected on the engine hot lamp control circuit.
    • The above conditions are present for at least 30 seconds.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Inspect for the following conditions:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    • Loose terminal connection
       -  Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
       -  Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
    • Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
    •  Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

  1. Normally, ignition feed voltage should be present on the control circuit with the PCM disconnected and with the ignition turned ON.

  2. This step tests for a shorted component, or for a short to B+ on the control circuit. Either condition will result in a measured current of more than 500 milliamps. This step also checks for a component that is causing an open circuit during operation, resulting in a measured current of 0 milliamps.

  3. This step tests for a short to voltage on the control circuit.

  4. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read-only memory (EEPROM). When you replace the PCM, you must program the new PCM.

DTC P1673 - Engine Hot Lamp Control Circuit

Step

Action

Values

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. Disconnect the PCM.
  3. Turn ON the ignition, leaving the engine OFF.
  4. Use a DMM in order to measure the voltage between the engine hot lamp control circuit at the PCM harness connector and ground.

Is the voltage near the specified value?

B+

Go to Step 3

Go to Step 6

3

  1. Connect a DMM in order to measure the current between the engine hot lamp control circuit at the PCM harness connector and ground.
  2. Monitor the current reading on the DMM for at least 2 minutes.

Is the current reading between the specified values?

0.05-0.5 Amps

(50-500 mA)

Go to Step 11

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the instrument panel, and leave the PCM disconnected.
  3. Turn the ignition ON, leaving the engine OFF.
  4. Use a DMM in order to measure the voltage between the engine hot lamp control circuit and ground.

Is the voltage at the specified value?

0 V

Go to Step 10

Go to Step 5

5

Locate and repair the short to voltage in the engine hot lamp 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

  1. Locate and repair any short to ground in ignition feed circuit for the instrument panel indicators. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse.

Did you complete the repair?

--

Go to Step 15

--

8

  1. Turn the ignition OFF.
  2. Disconnect the instrument cluster.
  3. Turn the ignition ON, leaving the engine OFF.
  4. Measure voltage between the ignition feed circuit for the instrument cluster indicators and ground.

Is the voltage near the specified value?

B+

Go to Step 9

Go to Step 13

9

  1. Test the engine hot lamp control circuit for an open or for a short to ground.
  2. If you find a problem, repair the condition as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

  1. Inspect the engine hot lamp control circuit and the instrument panel indicators ignition feed circuit for a poor connection at the instrument panel.
  2. If you find a problem, repair the condition as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

--

11

  1. Turn OFF the ignition switch.
  2. Reconnect the PCM.
  3. Disconnect the instrument cluster.
  4. Turn ON the ignition, leaving the engine OFF.
  5. Connect a test lamp between the engine hot lamp control circuit and the ignition feed circuit at the instrument panel harness connector.
  6. Use the scan tool outputs test function in order to cycle the engine hot lamp ON and OFF.

Does the test lamp flash ON and OFF?

--

Go to Diagnostic Aids

Go to Step 12

12

  1. Inspect the engine hot lamp control circuit for a poor connection at the PCM.
  2. If you find a problem, repair the condition as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Locate and repair any open in the ignition feed circuit to the I/P 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 replacement?

--

Go to Step 15

--

15

  1. Use a scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Setting the DTC, as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK