Service Manual Update - DTCs P0636 and P0637
Corporation.:00-02-36-001
Bulletin No.:
00-T-15
Category Type:
Chassis-02
Category:
Steering
Issue Date:
March, 2000
Subject:
Service manual update for the 2000 S-Series chassis service manual regarding DTCs P0636 and P0637 steering assist solenoid control circuit Low/High
Models Affected:
2000 Saturn S-Series Vehicles
Purpose:
The purpose of this bulletin is to update all the 2000 S-Series Chassis Service Manuals at your location.
Please obtain all the 2000 S-Series Chassis Service Manuals and make the necessary updates as indicated.
1. Cross out the following pages with a marker or pen:
^ Pages 142 and 143 for DTC P0636 Steering Assist Solenoid Control Circuit Low
^ Pages 144 and 145 for DTC P0637 Steering Assist Solenoid Control Circuit High
DTC P0636- STEERING ASSIST SOLENOID CONTROL UNIT-LOW VOLTAGE:
Service Manual update for pages 142 and 143 of the 2000 S-Series Chassis service manual. Refer to Technical Information Bulletin 00-02-36-001. March, 2000.
The electronic variable orifice (EVO) on DOHC engines varies the power steering pressure flow from the power steering pump. The PCM controls the steering assist solenoid by pulse width modulating (PWM) ignition voltage to the solenoid. The low side of the steering assist solenoid is tied directly to a low resistance resistor, which is tied directly to ground in the PCM. The PCM monitors the steering assist solenoid circuit for low and high voltage faults at all times (Off, On and PWM). DTC P0636 sets when the steering assist solenoid is commanded On or commanded to PWM (On-time only) and the feedback voltage at the PCM is low.
DTC PARAMETERS
DTC P0636 will set if the steering assist solenoid voltage is less than 3.0 volts when steering assist solenoid is commanded On.
DTC P0636 diagnostic runs continuously with ignition On and steering assist solenoid commanded On.
DTC P0636 is a type D DTC.
DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to command STEERING ASSIST SOLENOID On (No Assist), while monitoring the STEERING SOL.
- LOW VOLT test. When a fault (short to ground or shorted solenoid) exists, the scan tool will display TEST FAIL.
The test will fail only when the device is being commanded On and the voltage at the PCM is low. The test updates every 100 ms whenever the ignition is turned On and the device is being commanded On via the Scan tool or PCM.
Steering assist solenoid resistance: 8-12 ohms.
DTC P0367-STEERING ASSIST SOLENOID CONTROL CIRCUIT-HIGH VOLTAGE:
Service Manual update for pages 144 and 145 of the 2000 S-Series Chassis Service Manual. Refer to Technical Information Bulletin 00-02-36-001. March, 2000.
The electronic variable orifice (EVO) on DOHC engines varies the power steering pressure flow from the power steering pump. The PCM controls the steering assist solenoid by pulse width modulating (PWM) ignition voltage to the solenoid. The low side of the steering assist solenoid is tied directly to a low resistance resistor, which is tied directly to ground in the PCM. The PCM monitors the steering assist solenoid circuit for low and high voltage faults at all times (Off, On and PWM). DTC P0637 sets when the steering assist solenoid is commanded Off or commanded to PWM (Off-time only) and the feedback voltage at the PCM is high.
DTC PARAMETERS
DTC P0637 will set if the steering assist solenoid voltage is greater than 3.5 volts when steering assist solenoid is commanded Off.
DTC P0637 diagnostic runs continuously with ignition On and steering assist solenoid commanded Off.
DTC P0637 is a type D DTC.
DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to command STEERING ASSIST SOLENOID OFF (Full Assist), while monitoring the STEERING SOL. - OPEN or STEERING SOL. - HIGH VOLT test. When a fault (open or short to voltage) exists, the Scan tool will display TEST FAIL for both tests.
The test will fail only when the device is being commanded Off and the voltage at the PCM is high. The test updates every 100 ms whenever the ignition is turned ON and the device is being commanded Off via the Scan tool or PCM.
Steering assist solenoid resistance: 8-12 ohms.
Saturn bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer." They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your SATURN Retailer for information on whether your vehicle may benefit from the information.