When I use the turn signals all 4 corners of the car work fine. When the 4 way flashers are engaged three corners work fine but I get no Left Front blinker? Any ideas? How can the turn signals that go through the 4 way hazard switch work fine, but I lose the left front when the 4 ways are engaged?

 

Let's throw this up top again.

 

probably just the hazard switch on its way out.

 

I thought the same thing, but after abusing the hazard switch the song remains the same. I had thought that the turn signal circuit ran through the hazard switch, so it didn't make sense to me that although I lost the left front 4 way, I had all 4 corners of turn signals. I hate to swap known good parts without diagnosing the problem. But I agree, the hazard/flasher appears to be the weak link in the system.

 

On old cars you have a seperate flasher for the four ways and then the turn signals. Check the wiring diagrams, and look in the owners manual, to see where the flashers and 4 way boxes are. More then likley its the hazard portion of the flasher.

 

 

Tim, As I read it this article pertains to the turn signal indicators in the IPC (instrument panel cluster) which also work just fine. This is what's got me somewhat puzzled. Every lamp in the system works except the left front corner when the hazards are engaged.

 

DTC B2583 Left Front Turn Signal Monitor Circuit

Object Number: 74055 Size: MF

Circuit Description





The BCM monitors the LF turn signal circuit in order to determine the status of the turn signal switch. If the BCM detects an oscillating voltage on CKT 14, the BCM interprets this as a LF turn signal ON request from the turn signal switch. The BCM will stop energizing the LH DRL relay, which will disable the LF turn signal lamp (which is ON for the DRL), thus allowing the LF turn signal to flash. If the BCM does not detect an oscillating voltage on CKT 14, the BCM interprets this as the LF turn signal being OFF. The BCM will then energize the LH DRL relay and continue normal DRL operation. The BCM monitors the LF turn signal CKT 14 and determines how long voltage is applied. If the voltage is applied for longer than expected, a malfunction is present and a DTC will set.
Conditions for Setting the DTC

* The BCM detects continuous battery voltage on the LF turn signal monitor circuit.
* The condition must be present for longer than 5 seconds.

Action Taken When the DTC Sets

* Stores a DTC B2583 in the BCM memory.
* No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

* This DTC requires an ignition cycle in order to change from current to history.
* The BCM no longer detects continuous battery voltage on the LF turn signal monitor circuit for longer than 5 seconds.
* A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
* Use the IPC clearing DTCs feature.
* Use a scan tool.

Diagnostic Aids

* The following conditions may cause an intermittent malfunction:
o There is an intermittent short to voltage in CKT 14, CKT 16, or CKT 1314.
o The turn signal switch or the hazard switch is internally shorted or is sticking.
* The BCM needs to detect voltage oscillations on CKT 14 in order to de-energize the LF turn signal relay. If the BCM detects continuous voltage on CKT 14, the BCM interprets this as a short to voltage. The BCM will continue with normal DRL operation, and the LF turn signal will remain inoperative.
* If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Refer to Intermittents and Poor Connections .

Test Description

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

2.

This test will check if a DTC B2578 is stored in the BCM memory.
3.

This test will determine if there is a short to voltage in CKT 14.
4.

This test will determine if there is a short to voltage in CKT 1314.
5.

This step tests for an internal DRL relay short.
6.

This test determines if the short to voltage is located in the hazard warning switch.
7.

This test determines if the short to voltage is located in the turn signal switch.
8.

This test determines if the short to voltage is located in the I/P.

DTC B2583 -- LF Turn Signal Monitor Circuit Short to Voltage

Step


Action


Value(s)


Yes


No

1


Were you sent here from the BCM Diagnostic System Check?


--


Go to Step 2


Go to Diagnostic System Check - Body Control System

2


Using a scan tool, check for BCM DTC B2578.

Is DTC B2578 stored in the BCM memory?


--


Go to Step 14


Go to Step 3

3


1. Turn OFF the ignition switch.
2. Disconnect the LH DRL relay.
3. Turn ON the ignition switch.
4. Turn OFF the turn signals.
5. With a test light connected to ground, probe CKT 14 at the I/P electrical center LH DRL relay terminal. Refer to Electrical Center Identification Views for relay circuit location.

Is the test light ON?


--


Go to Step 6


Go to Step 4

4


With a test light connected to ground, probe CKT 1314 at the I/P electrical center LH DRL relay terminal. Refer to Electrical Center Identification Views for relay circuit location.

Is the test light ON?


--


Go to Step 13


Go to Step 5

5


Check for continuity between the LH DRL relay terminals 4 and 5 (or 87 and 87A).

Is there continuity?


--


Go to Step 17


Go to Step 9

6


1. Turn OFF the ignition switch.
2. Disconnect the hazard warning switch connector.
3. Turn ON the ignition switch.
4. With a test light connected to ground, probe CKT 14 at the I/P electrical center LH DRL relay terminal. Refer to Electrical Center Identification Views for relay circuit location.

Is the test light ON?


--


Go to Step 7


Go to Step 16

7


1. Turn OFF the ignition switch.
2. Disconnect the turn signal switch connector C211.
3. Turn ON the ignition switch.
4. With a test light connected to ground, probe CKT 14 at the I/P electrical center LH DRL relay terminal. Refer to Electrical Center Identification Views for relay circuit location.

Is the test light ON?


--


Go to Step 8


Go to Step 15

8


1. Turn OFF the ignition switch.
2. Disconnect the IPC connector.
3. Turn ON the ignition switch.
4. With a test light connected to ground, probe CKT 14 at the I/P electrical center LH DRL relay terminal. Refer to Electrical Center Identification Views for relay circuit location.

Is the test light ON?


--


Go to Step 11


Go to Step 12

9


Inspect for the following intermittent malfunctions:

* A short to voltage on CKTs 14, 16, or 1314.
* An internal short in the LH DRL relay.
* An internal short in the turn signal switch.
* An internal short in the hazard warning switch.
* A short at IPC terminal A14.

Was a problem found and repaired?


--


Go to Step 19


Go to Step 10

10


1. Turn OFF the ignition switch.
2. Reconnect or install any connectors or components that were disconnected or removed.
3. Turn ON the ignition switch.
4. Clear any DTCs. Refer to Clearing DTCs .
5. Wait 5 seconds and check for DTCs.

Does DTC B2583 set as current?


--


Go to Step 18


System OK

11


Locate and repair the short to voltage in CKT 14.

Is the circuit repair complete?


--


Go to Step 19


--

12


Locate and repair the short to voltage at the IPC connector terminal A15.

Is the circuit repair complete?


--


Go to Step 19


--

13


Locate and repair the short to voltage in CKT 1314.

Is the circuit repair complete?


--


Go to Step 19


--

14


Check for a short to voltage in CKT 16.

Was a condition found and repaired?


--


Go to Step 19


Go to Step 16

15


Replace the turn signal switch. Refer to Turn Signal and Multifunction Switch Assembly in Steering Wheel and Column.

Is the replacement complete?


--


Go to Step 19


--

16


Replace the hazard warning switch. Refer to Hazard Warning Switch Replacement - On Vehicle in Lighting Systems.

Is the repair complete?


--


Go to Step 19


--

17


Replace the LH DRL relay.

Is the replacement complete?


--


Go to Step 19


--

18


1. Replace the BCM. Refer to Body Control Module Replacement .
2. Program the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Is the replacement complete?


--


Go to Step 19


--

19


1. Turn OFF the ignition switch.
2. Reconnect or install any connectors or components that were disconnected or removed.
3. Turn ON the ignition switch.
4. Clear any DTCs. Refer to Clearing DTCs .

Are all DTCs cleared?


--


Go to Diagnostic System Check - Body Control System


--
Document ID# 187508
1997 Chevrolet/Geo Corvette

 

Wow! Tim, Thanks for your time. I will use this as a guide sometime tomorrow. Thanks again.