rebuilding a wrecked 98, got these codes p1514,p1571,andc1277,1278. anyone smart enough to tell me what parts to replace. also do you guys think this would keep the motor from reving past 2500 rpm and throwing out a reduced engine power display. any help would be appreciated. thanks greg

 

Does the codes have an "H" suffix or "HC"?

 

current codes not history codes

 

P1514H (tac system MAF performance)
P1571HC (ASR desired torque)
C1277H (requested torque signal CKT malfunction)
C1278H (TCS temporarally inhibited by PCM)
any clues what to fix. thanks greg

 

It appears the only one that is current is the first one. I'll list them all though:

P1571

CIRCUIT DESCRIPTION
The PCM supplies 5 volts on the desired torque circuit to the Electronic Brake And Traction Control Module (EBTCM) . The EBTCM toggles this 5 volt signal to a ground in order to produce a duty cycle signal. The signal is proportional to the amount of engine output torque reduction requested by the EBTCM. The EBTCM supplies this signal when it detects a wheel slip. In order to reduce engine output torque, the PCM reduces the amount of spark advance and in some cases, the PCM disables a number of fuel injectors. This diagnostic tests for a Desired Torque signal failure. If the PCM does not receive the Desired torque signal, this DTC sets.

CONDITIONS FOR RUNNING THE DTC


The traction control has not failed.
The engine speed is greater than 500 RPM for 20 second .
CONDITIONS FOR SETTING THE DTC
The desired torque signal is not received by the PCM for 3 seconds .

ACTION TAKEN WHEN THE DTC SETS


The PCM stores the DTC information into memory when the diagnostic runs and fails.
The Malfunction Indicator Lamp (MIL) will not illuminate.
The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC


A last test failed (current DTC) clears when the diagnostic runs and does not fail.
A History DTC clears after 40 consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
Use a scan tool in order to clear the MIL/DTC.
DIAGNOSTIC AIDS

IMPORTANT:


Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A. Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Diagrams.
Do not perform this diagnostic procedure if the customer's concern is not related to the ABS and/or the Traction Control systems. For an intermittent condition, refer to Symptoms. See: Diagnostic Information and Procedures\Symptoms
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.


This step determines if the EBTCM is receiving the 5 volts from the PCM. Use the connector test kit adaptor J 35616-A when probing the EBTCM connector.
If no DTCs are set, inspect connections at the EBTCM

C1277
Circuit Description
The PCM monitors various parameters and will not allow Traction Control/Active Handling (if equipped with RPO JL4) operation if any parameter falls beyond a predetermined value.

Conditions for Setting the DTC
A malfunction has been detected by the PCM. The PCM then causes TCS/Active Handling shutdown until the malfunction has been corrected.

Action Taken When the DTC Sets
This is a temporary operational malfunction. TCS/Active Handling (if equipped with RPO JL4) are disabled.


Indicators that turn on: Car Icon (TCS indicator)
Messages displayed on the DTC: Service Traction System
Service Active HNDLG (if equipped with RPO JL4)

Conditions for Clearing the DTC


Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
This code is for information only. It indicates there are no problems in the ABS/TCS/Active Handling system, is used as an aid to the technician.

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


Checks for proper duty cycle.
Checks for proper frequency.

C1278
Circuit Description
The PCM monitors various parameters and will not allow Traction Control/Active Handling (if equipped with RPO JL4) operation if any parameter falls beyond a predetermined value.

Conditions for Setting the DTC
A malfunction has been detected by the PCM. The PCM then causes TCS/Active Handling shutdown until the malfunction has been corrected.

Action Taken When the DTC Sets
This is a temporary operational malfunction. TCS/Active Handling (if equipped with RPO JL4) are disabled.


Indicators that turn on: Car Icon (TCS indicator)
Messages displayed on the DTC: Service Traction System
Service Active HNDLG (if equipped with RPO JL4)

Conditions for Clearing the DTC


Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
This code is for information only. It indicates there are no problems in the ABS/TCS/Active Handling system, is used as an aid to the technician.